(acovs11) 5th (asc5) th · 2015. 9. 27. · proceedings of the 11th australian conference on...

PROCEEDINGS OF THE

11TH AUSTRALIAN CONFERENCE ON VIBRATIONAL SPECTROSCOPY

(ACOVS11) AND THE 5TH ASIAN SPECTROSCOPY CONFERENCE (ASC5)

Incorporating a two day Workshop Series

28th-29th September, 2015.

29TH SEPTEMBER – 2ND OCTOBER, 2015

THE UNIVERSITY OF SYDNEY

ACOVS11/ASC5 Book of Abstracts Preface

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Preface

On behalf of the Organising Committees of the 11th Conference on Vibrational Spectroscopy (ACOVS11) and the 5th Asian Spectroscopy Conference (ASC5) it gives me great pleasure to welcome you to the University of Sydney. A special welcome to all who have travelled from as far away as Ireland, the United Kingdom, the United States of America, Germany, Hungary, France, Italy, Korea, Taiwan, India, Japan, China, Singapore, Thailand, Switzerland and of course our friends and neighbours from New Zealand.

This year the conference includes a two-day Workshop series that will be presented by a number of distinguished speakers. Topics include:

• Synchrotron THz and IR spectroscopy • Chemometrics • IR Sampling and Troubleshooting • FTIR Imaging: Resolution for every application • Elsevier’s Authors Workshop

The scientific program we hope is as ambitious and as successful as previous conferences. The conference program includes a Keynote Lecture, 15 Plenary Lectures, parallel sessions including 29 invited talks, 77 contributed talks and 46 posters held over two sessions. In total 167 papers will be presented during the combined conferences. We trust that you enjoy the meeting and find the diversity of the sessions both stimulating and rewarding. The conference organisers are always keen to support and encourage younger scientists and it is heartening to note that forty-one of the papers that are to be presented are by post-graduate students. The conference organisers are pleased to offer four prizes for the best student oral and poster presentations. The Student Oral and Poster Conference Prizes recognises outstanding presentations made by postgraduate students at the conference. Student poster presenters must be present and available to discuss their research with other delegates during the poster session. Posters will be judged on content, clarity, and effectiveness of overall presentation. Student conference attendees will cast their votes by secret ballot for the "Student's Choice Award" for both the oral and poster prize and the Plenary speakers will also vote for the "Plenary's Choice Award" also for one oral and poster prize. We are very grateful to the NSW Trade and Investment Agency and Bruker Pty Ltd who have provided sponsorship money for the student travel bursaries. I would sincerely like to thank the instrument companies for their continued support of ACOVS and ASC. This year we will have the pleasure of their company for four days as they will be exhibiting and demonstrating instrumentation and accessories during the conference. The exhibitors have a wealth of knowledge so please drop by their booth and ask lots of questions, they would be delighted to have your company. Finally, we are indebted to those who have provided finance and sponsorship without your generosity we would not be able to hold this conference.

Elizabeth Carter ACOVS11 Conference Chair

ACOVS11/ASC5 Book of Abstracts Table of Contents

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TABLE OF CONTENTS Preface ............................................................................................................................................................................................................................ i Local Organising Committee .......................................................................................................................................................................................... iii Steering Committees ...................................................................................................................................................................................................... iv General Information ........................................................................................................................................................................................................ v Acknowledgements ....................................................................................................................................................................................................... vii Workshop Program ...................................................................................................................................................................................................... viii Conference Program ...................................................................................................................................................................................................... x

KEYNOTE LECTURE ............................................................................................................................................................................................... 1 PLENARY LECTURES ............................................................................................................................................................................................. 4

SESSION I – SYNCHROTRON ....................................................................................................................................................................... 21 SESSION II – PLASMONICS ........................................................................................................................................................................... 27 SESSION III – CHIRALITY ............................................................................................................................................................................... 32 POSTER SESSION I ........................................................................................................................................................................................ 37 SESSION IV – BIOSPECTROSCOPY I: Disease ............................................................................................................................................ 68 SESSION V – ULTRAFAST AND NON-LINEAR SPECTROSCOPY I ............................................................................................................. 73 SESSION VI – MATERIALS I ........................................................................................................................................................................... 83 SESSION VII – BIOSPECTROSCOPY II: Cells and Bacteria .......................................................................................................................... 88 SESSION VIII – FUNDAMENTAL .................................................................................................................................................................... 96 SESSION IX – SYNCHROTRON THZ ........................................................................................................................................................... 104 SESSION X – MATERIALS II ......................................................................................................................................................................... 109 SESSION XI – SINGLE MOLECULE ............................................................................................................................................................. 113 SESSION XII – AGRICULTURE .................................................................................................................................................................... 117 SESSION XIII – NANOTECHNOLOGY .......................................................................................................................................................... 122 SESSION XIV – BIOSPECTROSCOPY III ..................................................................................................................................................... 128 SESSION XV - MINEROLOGY/GEMMOLOGY ............................................................................................................................................. 133 SESSION XVI – FORENSICS ........................................................................................................................................................................ 138 SESSION XVII – CHEMOMETRICS .............................................................................................................................................................. 142 SESSION XVIII – EXHIBITORS ..................................................................................................................................................................... 146 SESSION XIX – BIOSPECTROSCOPY IV .................................................................................................................................................... 151 SESSION XX – ENVIRONMENTAL ............................................................................................................................................................... 156 POSTER SESSION II ..................................................................................................................................................................................... 163 SESSION XXI – ARCHEAOLOGY I ............................................................................................................................................................... 184 SESSION XXII – ULTRAFAST AND NON-LINEAR SPECTROSCOPY II ..................................................................................................... 188 SESSION XXIII – ARCHEAOLOGY II ............................................................................................................................................................ 198 SESSION XXIV – MAPPING AND IMAGING ................................................................................................................................................. 203 SESSION XXV – SYNCHROTRON III ........................................................................................................................................................... 206 SESSION XXVI – NEUTRON SPECTROSCOPY .......................................................................................................................................... 211 SESSION XXVII – PLASMONICS II ............................................................................................................................................................... 215

Author Index ............................................................................................................................................................................................................... 219

ACOVS11/ASC5 Book of Abstracts Local Organising Committee

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LOCAL ORGANISING COMMITTEE

ACOVS

Elizabeth Carter The University of Sydney

Annette Dowd University of Technology Sydney

Anne Rich University of NSW

ASC

Don McNaughton Monash University

Bayden Wood Monash University

Philiip Heraud Monash University

Peter Fredericks Queensland University of Technology

Keith Gordon University of Otago

Mark Waterland Massey University

Paul Stoddart Swinburne University

ACOVS11/ASC5 Book of Abstracts Steering Committees

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STEERING COMMITTEES

ACOVS

Robert Armstrong The University of Sydney

David Beatti The University of South Australia

Stephen Best The University of Melbourne

Bill Van Bronswijk Curtin University

Elizabeth Carter The University of Sydney

Peter Fredericks Queensland University of Technology

David Griffith University of Wollongong

Keith Gordon Otago University

Don McNaughton Monash University

ASC – International Steering Committee

I-Chia Chen Taiwan

Yit-Tsong Chen Taiwan

Sanong Ekgasit Thailand

Keith Gordon New Zealand

Hiro-o Hamaguchi* Japan

Koichi Iwata Japan

Taiha Joo S. Korea

Scott Kable Australia

Sang Kyu Kim S. Korea

Seong-Keun Kim** S. Korea

Soo-Ying Lee Singapore

Don McNaughton Australia

Nobuhiro Ohta Japan

Yukihiro Ozaki Japan

Mrinalini Puranik India

Bin Ren China

Tahei Tahara Japan

Zhong-Qun Tian** China

Siva Umapathy** India

Sanjay Wategaonkar India

Honxing Xu China

Edwin Yeow Singapore

Hairong Zheng China

* Founding Chairman

** Past ASC Meeting Chairmen

ACOVS11/ASC5 Book of Abstracts General Information

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GENERAL INFORMATION

Venue Location: The venue for ACOVS11 is the Holme Building on Science Road, which is located on the grounds of the University of Sydney. See the circled area on the map below.

The Keynote and Plenary lectures will be held in the Refectory, the parallel sessions will be held in the

Refectory as well as the Sutherland and Cullen Rooms and are located on level 1 of the Holme Building. The workshops held on Monday and Tuesday the 28th and 29th of September will be held in the Sutherland and Cullen rooms. The poster sessions will be held in the Bevery.

Registration: The registration and information desk is located in the Drawing room and/or Collanade and will be available

from 9.00 am Monday the 28th of September, 2015. Messages: An information board will be located in the registration area and any message received for delegates will be

posted on it. There is a fully serviced Australia Post office in Science Road in the Bank Building. Banking Facilities: These are located as follows (see map below): (A) Wentworth Building – Commonwealth Bank and National Australia Bank ATM’s are also available at these buildings. (B) ANZ ATM in the New Law Building Annex (C) Commonwealth Bank ATM in Manning House (D) Commonwealth Bank ATM in the Holme Building

Meals: Morning tea, lunch and afternoon tea will be provided on the Collanade and in the event of poor weather it

will be moved to the Bevery. Exhibition: The Exhibition will be open from Tuesday the 29th of September at 9 am until 12.00 pm on Friday, 2nd

October. Conference Mixers: All delegates are invited to the pre-Conference mixer and pre-registration, which will be held on Monday from

17.00 to 18.30. Conference Dinner: The Conference Dinner will be held on Wednesday evening at the Australian National Maritime Museum.

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ACOVS11/ASC5 Book of Abstracts General Information

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1) Warsash Scientific Pty Ltd 2) Renishaw plc 3) Agilent 4) Quark Photonics/Horiba 5) ThermoFisher Scientific 6) Lastek 7) PerkinElmer 8) Bruker Pty Ltd 9) NSW Government 10) WiTEC 11) QbDC 12) MEP Instruments

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ACOVS11/ASC5 Book of Abstracts Acknowledgements

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ACKNOWLEDGEMENTS

ACOVS11/ASC5 Book of Abstracts Workshop Program

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WORKSHOP PROGRAM

DAY 1 – MONDAY, 28TH SEPTEMBER

17.00 – 18.30 PRE-CONFERENCE MIXER + REGISTRATION

CHEMOMETRICS WORKSHOP – BRAD SWARBRICK SYNCHROTRON THZ AND IR WORKSHOP 9:00 - 9:40 BRAD SWARBRICK

Quality by Design Consultancy Introduction to Chemometrics

DOMINIQUE APPADOO Australian Synchrotron, Clayton, Australia New & Future Techniques at the THz/Far-IR beamline

9:40 – 10:20 Data Visualization MICHAEL MARTIN Advanced Light Source, Berkley, USA THz/Far-IR condensed matter applications

10.20 – 10.40 MORNING TEA 10.40 – 11.20 Pre-treatments used on Spectroscopic Data GREG METHA

The University of Adelaide, Australia Interpretation of metal custer spectra in THz/Far-IR using DFT calculation

11.20 – 12.00 ROBERT FALCONER University of Sheffield, Sheffield, UK THz spectroscopy of proteins

12.00 – 12.40 Principal Component Analysis of Spectra (Part 1) PASCALE ROY Soeil Synchrotron, France Far- and Mid-IR analysis of condensed matter at the AILES beamline - Synchrotron SOLEIL

12.40 – 13.40 LUNCH 13.40 – 14.00 Principal Component Analysis of Spectra (Part 2) ROBBIN VERNOOIJ

Monash University, Australia DNA + drugs + new liquid cell

14.00 – 14.20 COURTNEY ENNIS LaTrobe University, Australia Low-Temperature Reflection Technique at the THz beamline

14.20 – 14.40 MARK TOBIN Australian Synchrotron, Clayton, Australia Introduction to IR Microscopy beamline – capabilities and advantages

14.40 – 15.00 SORINA POPESCU Memjet, Australia Applications of Synchrotron Light in Inkjet Technology

15.20 – 15.40 AFTERNOON TEA 15.40 – 16.00 Chemometric Model Validation Techniques BAYDEN WOOD

Monash University, Australia Applications of Synchrotron IR in disease diagnosis

16.20 – 16.40

16.20 – 16.40 Using Multivariate Models in Practice KEITH BAMBERY Australian Synchrotron, Clayton, Australia Data analysis methods for synchrotron infrared microspectroscopy

16.40 – 17.00 Course Summary and Wrap Up

ACOVS11/ASC5 Book of Abstracts Workshop Program

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DAY 2 – TUESDAY, 29TH SEPTEMBER 8.30 – 9.00 Registration 10.20 – 10.40 Morning Tea – Assemble Posters

IR SAMPLING AND TROUBLESHOOTING 10.40 – 11.00 JENNI BRIGGS

PIKE Technologies, USA 11.00 – 11.20 11.20 – 11.40 11.40 – 12.00 12.00 – 12.20 12.20 – 12.40 12.40 – 13.40 LUNCH FTIR IMAGING – RESOLUTION FOR EVERY APPLICATION ELSEVIER – AUTHORS WORKSHOP 13.40 – 14.00 DAVID HAINES

Agilent, Melbourne, Australia Advances in FTIR Imaging – Breaking Spatial Resolution Limits

DON MCNAUGHTON Monash University, Australia How to structure/write a paper

14.00 – 14.20 FIONA BARRON Elsevier, Chatswood, Australia Ethics and Publishing – Plagiarism

14.20 – 14.40 THOMAS KLINGLER Elsevier, Chatswood, Australia Author and Journal Metrics: Impact Factors, Scopus/Mendeley

14.40 – 15.00 BAYDEN WOOD Monash University, Australia Biomedical applications of FTIR imaging

FIONA BARRON Elsevier, Chatswood, Australia Authorship

15.00 – 15.20 FIONA BARRON Elsevier, Chatswood, Australia Open Access

15.20 – 15.40 AFTERNOON TEA 15.40 – 16.00 PETER LASCH

Robert Koch-Institute, Berlin, Germany Technical aspects of Mid_IR hyperspectral imaging for biomedical applications

DON MCNAUGHTON Monash University, Australia The Role of the Editor and Reviewer

16.00 – 16.20 DON MCNAUGHTON Monash University, Australia WHY IS A PAPER REJECTED?

16.20 – 16.40 PHIL HERAUD Monash University, Australia FTIR Imaging of photosynthetic cells and tissues

DON MCNAUGHTON AND ELIZABETH CARTER Monash University and The University of Sydney, Australia GRILL AN EDITOR…..

16.40 – 17.00 Open discussion and wrap up

ACOVS11/ASC5 Book of Abstracts Conference Program

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CONFERENCE PROGRAM

DAY 1 – TUESDAY, 29TH SEPTEMBER

10.20 – 10.40 Morning Tea – Assemble Posters

13.00 – 14.00 Lunch

15.40 – 16.00 Afternoon Tea

8.30 – 9.00 REGISTRATION 9.00 – 9.20 OPENING ADDRESS – DR CHRISTOPHER ARMSTRONG

Director of the Office of the NSW Chief Scientist and Engineer 9.20 – 10.20 KEYNOTE LECTURE – GIULIETTA SMULEVICH

Università degli Studi di Firenze, Florence, Italy Bridging Molecular Dynamics and Resonance Raman Spectroscopy to Highlight the Structural Properties of Bacterial Hemoglobins

SESSION I – SYNCHROTRON CHAIR: R. J. FALCONER 10.40 – 11.20 PLENARY LECTURE – M. MARTIN

Advance Light Source, Berkley, USA Infrared Spectroscopy in 3D and at Nano Scales

11.20 – 11.40 M. RUZI*, C. P. ENNIS, D. R. T. APPADOO, E. G. ROBERTSON LaTrobe University, Australia Optical Constants of Aerosols from Synchrotron Infrared Spectroscopy

11.40 – 12.00 R. AUCHETTL*, C. ENNIS, M. RUZI, E. G. ROBERTSON LaTrobe University, Australia Synchrotron studies of Titan’s cyanide haze

12.00 – 12.20 M.J. TOBIN*, K. R. BAMBERY, J. VONGSVIVUT, D. E. MARTIN, L. PUSKAR, D. A. BEATTIE, E. P. IVANOVA, S. H. NGUYEN, H. K. WEBB

Australian Synchrotron, Clayton, Australia Single Contact ATR Mapping of Soft Materials by Synchrotron FTIR

12.20 – 12.40 R. R. VERNOOIJ*, T. JOSHI, B. R. WOOD, D. APPADOO, E. I. IZGORODINA, B. GRAHAM, P. J. SADLER, L. SPICCIA

Monash University, Australia Vibrational spectroscopic studies of photoactivatable diazido Pt(IV) anticancer complexes

12.40 – 13.00 M. CHEAH - INVITED The Australian National University, Canberra, Australia Mechanism of water oxidation by Photosystem II: water exchange kinetics, FTIR and isotope effects. A presentation in memory of Warwick Hillier

SESSION II – PLASMONICS CHAIR: A. DOWD 14.00 – 14.40 PLENARY LECTURE – B. REN

Xiamen University, Xiamen, China Surface- and Tip-Enhanced Raman Spectroscopy from Mechanism to Applications

14.40 – 15.00 N. HAYAZAWA -INVITED RIKEN, Saitama, Japan Nanoscale optical properties visualized by tip-enhanced Raman & THz Raman spectroscopy

15.00 – 15.20 G. C. PHAN-QUANG, H. K. LEE, I. Y. PHANG, X. Y. LING* Nanyang Technological University, Singapore Plasmonic Colloidosomes as Three-dimensional SERS Platforms with Enhanced Surface Area for Multiphase Sub-microliter Toxin Sensing

15.20 – 15.40 Y. LIU*, S. PEDIREDDY, Y. H. LEE, R. HEGDE, W. W. TJIU, Y. CUI, X. Y. LING Nanyang Technological University, Singapore Designing Hot Spots over Hot Spots for More Efficient Surface-enhanced Raman Scattering (SERS)

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17.00 – 18.00 Poster Session 1 (see next page)

SESSION III – CHIRALITY CHAIR: B. R. WOOD 16.00 – 16.20 T. ISHIBASHI*, M. OKUNO - INVITED

University of Tsukuba, Tsukuba, Japan Heterodyne-detected chiral Vibrational SFG spectroscopy

16.20 – 16.40 H. OKAMOTO - INVITED Institute of Molecular Science, Okazaki, Japan Circular Dichroism Nanospectroscopy of Metal Nanostructures

16.40 – 17.00 S. OSTOVAR POUR*, L. ROCKS, K. FAULDS, D. GRAHAM, V. PARCHANSKY, P. BOUR, E. W. BLANCH RMIT University, Melbourne, Australia Through-Space Transfer of Chiral Information Mediated by a Plasmonic Nanomaterial


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17.00 –18.30 POSTER SESSION I PSI-1 A. M. RICH*, N. H. HAZRIN-CHONG, C. E. MARJO, T. DAS, M. MANEFIELD

Surface Analysis by ATR-FTIR Reveals Biogenic Oxidation of Sub-bituminous Coal by Pseudomonas fluorescens PSI-2 J. LEE*, B. WEN, E. CARTER, V. COMBES, G. E. GRAU, P. LAY

Infrared Spectroscopic Differentiation of the Biochemistry of Pathogenic Cellular Microparticles Released from a Cellular Model of Septic Shock

PSI-3 B. STORK AND A. DOWD*

Vibrational spectroscopy structural study of the spontaneous membrane inserting protein CLIC1 PSI-4 K. AL-JORANI*, L. LIN, G. B. DEACON, D. MCNAUGHTON, B. R. WOOD

Characterization of polyfluorophenyl substituted organoamidoplatinum(II) compounds using some spectroscopic methods PSI-5 R. HAPUTHANTHRI*, G. DEACON, R. OJHA, D. MCNAUGHTON, E. LIPIEC, B. R. WOOD

Vibrational Spectroscopic Investigation into the Binding of Platinum Complexes with DNA PSI-6 L. YANG*, C. FUI ,S. XU, W. XU

Highly selective and sensitive detection of thrombin using aptamer-based SERS sensor PSI-7 R. DENG*, H. QU, L. LIANG, W .XU, C. LIANG, S. XU

SERS Spectroscopy for Probing Biomolecular Dynamic Changes of Cancer Cell Treated with Aptamer-drug Conjugate PSI-8 A. SAFITRI*, J. LEE, E. A. CARTER, K. BAMBERY, M. J. TOBIN, A. LEVINA, P. A. LAY

Investigating the Effects of Anti-diabetic Drugs on Glucose Metabolism in Insulin-sensitive Cells by Combining Biospectroscopic Study and Biochemistry Assay

PSI-9 S. KUBOTA*, M. MIZUNO, H. KANDORI, Y. MIZUTANI Chromophore structures in the early intermediates of light-driven chloride ion pumps

PSI-10 K. OIKAWA*, M. MIZUNO, H. KANDORI, Y. MIZUTANI Long-range coupling between the chromophore and the proton donor in the K intermediate of Gloeobacter rhodopsin

PSI-11 D. CHRISTENSEN*, B. R. WOOD, P. COOK, J. BEARDALL Using Vibrational spectroscopy and multivariate statistics to quantify seagrass health

PSI-12 R. LYU*, L. WANG, X. WANG, B. LIU, Y. DAI Construction of an angle-resolved spectrometer based on rotational arms

PSI-13 M. GEISLER, A. DOWD*, S. ZHU A comparative study of geometries for surface enhanced Raman spectroscopy

PSI-14 D. STOCKDALE*, A. DOWD Controlling the Structure of Silver Nanosponges for SERS Substrates

PSI-15 M. N. EKVALL, Y. CUI, M. R. LEE*, I. Y. PHANG, X. Y. LING

Conferring Temporal and Mechanical Stability to Surface-enhanced Raman Scattering (SERS) Plasmonic Security Label by Combining Atomic Layer Deposition and Polymeric Coating Techniques

PSI-16 J. SON*, C. KULSHRESHTHA, K. CHO, T. JOO Charge Transfer Mechanism Study of Polymer/PC[70]BM Bulk heterojunction Films & Implications for Organic Photovoltaics

PSI-17 W. HEO*, N. UDDIN, C. H. CHOI, T. JOO Excited State Proton Transfer Dynamics of HPTS

PSI-18 M. ANAN*, T. TAKAYA, K. IWATA Excited State Dynamics of Three Carotenoids Observed with Femtosecond Time-Resolved Absorption and Stimulated Raman Spectroscopy in Near-IR

PSI-19 C. E. MARJO, S. GATENBY*, A. RICH, S. CHEE Deterioration of the polyurethane ester PUR (ES) in the Speedo swimwear collection and monitoring the chemical aging by ART-FTIR measurement of the urethane peak

PSI-20 J.-H. ZHONG*, J. ZHANG, X. JIN, J.-Y. LIU, D.-Y. WU, D.-P. ZHAN, B. REN Raman Spectroelectrochemistry Study of Interfacial Capacitance and Defect Density Dependent Electrochemical Activity of Single Layer Graphene

PSI-21 T. CHAROENSUK*, C. SIRISATHITKUL AND U. BOONYANG

Structural Changes in 3DOM-BG Scaffold by Additional Phase Component PSI-22 G. LEE, T. JOO*

Photoluminescence of Carbon Nanodots PSI-23 T. T. M. HO, K. E. BREMMELL, M. KRASOWSKA, S. V. MACWILLIAMS, C. J. E. RICHARD, D. N. STRINGER, D. A. BEATTIE*

In Situ ATR FTIR Spectroscopic Study of Formation and Hydration of a Fucoidan/Chitosan Polyelectrolyte Multilayer PSI-24 S. SESHADRI*, M. P. RASHEED

Vibrational Spectroscopic (FTIR And FT-RAMAN) Studies, Homo Lumo Analysis, NMR Chemical Shifts and Electrostatic Potential Surface of 2,3-Dibromofuran

PSI-25 E. YOON*, T. JOO Tunable Near-infrared Femtosecond Optical Parametric Oscillator Based on a PPSLT Crystal

PSI-26 C.-C. CHEN, F.-Y. LIU, H.-P. LIN, W. W. LEE* Controlled Hydrothermal Synthesis of BiOCl/PbBiO2Cl, BiOCl/PbBiO2Cl/PbO, and PbBiO2Cl/PbO Composites Exhibiting Visible-Light Photocatalytic Activity

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WITHDRAWN


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DAY 2 – WEDNESDAY, 30TH SEPTEMBER

10.40 – 11.00 Morning Tea

SESSION IV – BIOSPECTROSCOPY I: DISEASE

SESSION V – ULTRAFAST AND NON LINEAR SPECTROSCOPY I

SESSION VI – MATERIALS I

CHAIR: P. HERAUD CHAIR: H. IHEE CHAIR: S. WATEGAONKAR 9.00 – 9.20 PLENARY LECTURE - A. G. SHEN,

X. D. ZHOU, J. M. HU* Wuhan University, Wuhan, China Bio-Raman spectroscopy: A Bridge between Pathological Research and Clinical Diagnosis of Disease

PLENARY LECTURE - M. FUJII Tokyo Institute of Technology, Yokohama, Japan Gas Phase Spectroscopy of Neurotransmitters and Partial Peptides of Receptor by IR-UV Double Resonance Spectroscopy

N. OHTA - INVITED National Chiao Tung University, Hsinchu, Taiwan Electroabsorption and Electrophotoluminescence Spectroscopies in Optoelectronic Materials

9.20 – 9.40 C. WANG - INVITED National Sun Yat-Sen University, Taiwan VUV Photoelectron Spectroscopy of Aqueous Aerosols: Implications in the Biological and Environmental Sciences

9.40 – 10.00 H. SATO*, B. B. ANDRIANA, H. MATSUYOSHI Kwansei Gakuin University, Sanda, Japan Raman Spectroscopy for Practical Application in Medicine and Biology

D. L. PHILLIPS - INVITED University of Hong Kong, Hong Kong Time-Resolved Spectroscopic Studies of Selected Aromatic Carbonyl Compounds in Aqueous Solutions

M. R. WATERLAND Massey University, Palmerston North, New Zealand Using resonant Raman scattering from excitonic states to determine orientation of electronic transition dipoles

10.00 – 10.20 D. PEREZ-GUITA*, P. HERAUD, T. PATCHARAPORN, M. WONGWATTANAKUL, P. CHATCHAWAL, A. KHOSHMANESH, P. JEARANAIKOON, M. W. A. DIXON, L. TILLEY, D. MCNAUGHTON, B. R. WOOD Monash University, Australia Diagnosis of malaria using ATR-FTIR. First trial study

H.-S. TAN - INVITED Nanyang Technological University, Singapore Ultrafast multi-dimensional electronic spectroscopy and its applications to the study of Light Harvesting Complexes

D. A. BEATTIE*, J. ADDAI-MENSAH, A. BEAUSSART, G. V. FRANKS, K.-Y. YEAP University of South Australia, Mawson Lakes, Australia In Situ Particle Film ATR FTIR Spectroscopy of poly (N-isopropyl acrylamide) Adsorption on Talc

10.20 – 10.40 A. LEVINA, J. B. AITKEN, E. A. CARTER, J. LEE, H. H. HARRIS, R. MAK, M. WOOD, H. O’RILEY, A. I. MCLEOD, L. WU, B. LAI, L. FINNEY, S. CHEN, S. VOGT, D. PATERSON, D. L. HOWARD, M. D. DE JONGE, M. J. TOBIN, P. A. LAY* The University of Sydney, Australia Multi-modal Imaging/Mapping: Understanding Disease Processes and Their Treatments

S. DONG, D. TRIVEDI, S. CHAKRABORTTY, T. KOBAYASHI, Y. CHAN, O. V. PREZHDO, Z.-H. LOH* - INVITED

Nanyang Technological University, Singapore Ultrafast Charge Migration and Coherent Phonon Dynamics Driven by Excitonic Quantum Coherence in CdSe Nanocrystals

WITHDRAWN


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12.30 – 13.30 Lunch (ASC International Steering Committee Meeting in the Chancellors Room) 13:30 Delegates touring ANSTO assemble at the Bevery 13:45 Delegates touring the AINST Building assemble at the Registration Desk 13:30 Delegates touring the Macleay Museum assemble at the Bevery

18.00 – 23.00 CONFERENCE DINNER – AUSTRALIAN NATIONAL MARITIME MUSEUM

18:00 – 18:45 COCKTAILS ON THE HMAS VAMPIRE

18:30 – 19:00 PRIVATE AFTER HOURS TOUR OF THE MUSEUM

19:00 – 23:00 CONFERENCE DINNER

SESSION VII – BIOSPECTROSCOPY II: CELLS AND BACTERIA

SESSION V (CONT.) – ULTRAFAST AND NON LINEAR SPECTROSCOPY I

SESSION VIII – FUNDAMENTAL

CHAIR: J. M. HU CHAIR: M. FUJII CHAIR: E. K. L. YEOW 11.00 – 11.20 M. M. HLAING, M. DUNN,

S. L. MCARTHUR, P. R. STODDART* -INVITED Swinburne University of Technology, Hawthorn, Australia Factors Influencing Bacterial Identification by Raman Spectroscopy

PLENARY LECTURE – H. IHEE KAIST & IBS, Daejeon, South Korea Ultrafast X-ray liquidography and crystallography capture molecular structural dynamics

S. WATEGAONKAR *, A. BHATTACHERJEE - INVITED Tata Institute of Fundamental Research, Mumbai, India CH•••O Hydrogen bond mediated microsolvation of imidazole derivatives

11.20 – 11.40 M. ANDO, H. HAMAGUCHI* - INVITED Waseda University, Tokyo, Japan Automatic and Objective Cell Discrimination by Raman Spectroscopy with Multivariate Curve Resolution Analysis

M. MIZUNO*, A. NAMAJIMA, H. KANDORI, Y. MIZUTANI - INVITED Osaka University, Osaka, Japan Structural evolution of the retinal chromophore in the photocycle of microbial ion pumps

11.40 – 12.00 N. I. SMITH - INVITED Osaka University, Osaka, Japan Quantitative approaches to surface-enhanced Raman measurements inside a cell

Y. MIZUTANI*, M. KONDOH, N. FUJII, M. MIYAMOTO, M. MIZUNO, H. ISHIKAWA - INVITED Osaka University, Osaka, Japan Watching energy flow in proteins

B. D. ADAMSON, N. J. A. COUGHLAN, P. MARKWORTH, E. J. BIESKE* University of Melbourne, Australia Photoisomerization Action Spectroscopy – Using Light to Change the Shape of Molecular Ions

12.00 – 12.20 P. HERAUD*, O. SACKETT, K. PETROU, J. BEARDALL Monash University, Australia Vibrational Spectroscopy of Southern Ocean Phytoplankton: a new approach for understanding drivers of primary productivity

M. IWAMURA*, K. NOZAKI, S. TAKEUCHI, T. TAHARA - INVITED University of Toyama, Toyama, Japan Structural Change Dynamics of Oligomers of Gold(I) Complex Observed by Ultrafast Spectroscopy

H. R. ZHENG*, W. GAO, E. J. HE, Q. Y. HAN, AND J. DONG Shaanxi Normal University, Xi’an, China Spectral enhancement of lanthanide doped luminescent hybrid nanosystem

12.20 – 12.40 H. NOOTHALAPATI*, M. KAWAMUKAI, T. YAMAMOTO Shimane University, Shimane, Japan Visualizing Fungal Cell Wall Architecture by Confocal Raman Microscopy

W. Q. CHEN, F. ZHOU, W. JI * - INVITED National University of Singapore, Singapore Multiphoton Absorption Spectroscopy of Two-Dimensional Materials

S. K. KIM Seoul National University, Seoul, South Korea Spectroscopic study of anomalous charge distributions in molecular ions

12.40 – 13.00 H. KANDORI - INVITED

Nagoya Institute of Technology, Nagoya, Japan Spectroscopic Study of Light-Driven Sodium-Pumping Rhodopsin

T. ISHIKAWA, Y. NAITO, Y. KAWAKAMI, H. ITOH, K. YAMAMOTO, H. KISHIDA, T. SASAKI, M. DRESSEL, Y. TANAKA, K. YONEMITSU, S. IWAI* Tohoku University, Sendai, Japan Driving charge and vibrational motions in strongly correlated organic conductors by nearly single-cycle 7fs, 10 MV/cm infrared strong field

O. KRECHKIVSKA, G. B. BACKSAY, T. P. TROY, K. NAUTA, S. H. KABLE, T. W. SCHMIDT* UNSW Sydney, Australia C2 – A Remote Probe for Combustion and Astrophysics


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DAY 3 – THURSDAY, 1ST OCTOBER

10.40 – 11.00 Morning Tea – Assemble Posters

SESSION IX – SYNCHROTRON THZ SESSION X – MATERIALS II SESSION XI – SINGLE MOLECULE CHAIR: P. FREDERICKS CHAIR: M. WATERLAND CHAIR: G. SMULEVICH 9.00 – 9.20 PLENARY LECTURE - R. J. FALCONER*,

V. P. WALLACE, J. A. ZEITLER , S. UDDIN, C. F. VAN DER WALLE University of Sheffield, Sheffield, UK Terahertz Spectroscopy of Proteins, Peptides and their Respective Hydration Layers

Q. XIONG Nanyang Technological University, Singapore Interlayer Vibrational Modes in 2D Transitional Metal Dichalcogenides

PLENARY LECTURE - E. K. L. YEOW Nanyang Technological University, Singapore Hard Truths about Soft Matter: From Single Polymer Chains to Single Swarming Bacteria 9.20 – 9.40 G. S. HUFF*, W. K. C. LO,

J. D. CROWLEY, K. C. GORDON University of Otago, Dunedin, New Zealand Coupling between excited states in TPA-substituted pyridyl-triazole complexes

9.40 – 10.00 A. MECHLER*, R. SEOUDI, K. KULKARNI, M. DELBORGO, P. PERLMUTTER, M-I AGUILAR, A. DOWD LaTrobe University, Australia Synchrotron far-IR characterization of self-assembling β3 peptides

A. GUPTA*, M. AGRAWAL M.J.P. Rohilkhand University, Bareilly, India Analysis of Experimental Spectra (FT-IR, FT Raman, UV and NMR) of some pharmaceutical compounds based on Density Functional Theory Calculations

T. D. M. BELL*, D. R. WHELAN, A. BRICE, G. W. MOSELEY - INVITED Monash University, Australia Single molecule super-resolution imaging of microtubules in cells expressing Rabies virus proteins

10.00 – 10.20 D. APPADOO*, R. PLATHE, C. MEDCRAFT, A. WONG, C. ENNIS Australian Synchrotron, Clayton, Australia THz/Far-IR condensed-phase capabilities & studies at the Australian Synchrotron

J. E. BARNSLEY*, C. B. LARSEN, G.SHILLITO, H. VAN DER SALM, N. T. LUCAS, K. C. GORDON University of Otago, Dunedin, New Zealand Donor-Acceptor Interactions of 2,1,3-Benzothiadiazole Push-Pull Dyes; An Experimental and Computational Study

10.20 – 10.40 T. L. TAN*, G. ARUCHUNAN, L. L. NG, M. G. GABONA, A. WONG, D. R. T. APPADOO, D. MCNAUGHTON Nanyang Technological University, Singapore High-resolution synchrotron FTIR spectroscopy of cis-ethylene-d2 (cis-C2H2D2): rovibrational constants of the ground and ν7 = 1 states

H. SOLEIMANINEJAD*, T. A. SMITH, C. A. SCHOLES University of Melbourne, Australia Time-Resolved and Polarised Evanescent Wave-Induced Fluorescence Spectroscopic Measurements of Fluorophores Near an Interface

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12.40 – 13.40 Lunch (ACOVS Steering Committee Meeting in the Chancellors Room)

SESSION XII – AGRICULTURE SESSION XIII – NANOTECHNOLOGY SESSION XIV – BIOSPECTROSCOPY III CHAIR: E. A. CARTER CHAIR: A. DOWD CHAIR: R. S. ARMSTRONG 11.00 – 11.20 PLENARY LECTURE - D. COZZOLINO

The University of Adelaide, Adelaide, Australia Truth or Fraud – The Role of Vibrational Spectroscopy in Food Authenticity

M.-J. CHIU, L.-K. CHU* National Tsing Hua University, Hsinchu, Taiwan Using Tryptophan as an in situ Fluorescent Thermometer to Quantify the Photothermal Efficiency of Gold Nanoparticles

E. W. BLANCH – INVITED RMIT University, Melbourne, Australia Raman optical activity: Biospectroscopy with a twist

11.20 – 11.40 M. A. KHAN*, R. K. ZHENG The University of Sydney, Australia Insight into CMOS-MEMS device using Energy Dispersive X-Ray Spectroscopy

T. OGURA*, S. NAKASHIMA, K. SHINZAWA-ITOH, S. YOSHIKAWA - INVITED University of Hyogo, Hyogo, Japan Molecular Mechanisms of Cytochrome c Oxidase as Studied by Vibrational Spectroscopy

11.40 – 12.00 S. FOWLER, H. SCHMIDT, R. VAN DE VEN, D. L. HOPKINS NSW Department of Primary Industries, Cowra, Australia Prediction of lamb meat quality using a Raman spectroscopic hand held device

S. L. ZHU*, L. XIAO, M. CORTIE University of Technology Sydney, Broadway, Australia Surface Enhanced Raman Spectroscopy on Metal Nitride Thin Films

M. M. HLAING*, B. R. WOOD, D. MCNAUGHTON, D. Y. YING, M. A. AUGUSTIN CSIRO Breakthrough Bioprocessing, Victoria, Australia Characterisation of the molecular composition and impact of stresses on microencapsulated Lactobacillus rhamnosus GG using Raman spectroscopy

12.00 – 12.20 G. P. S. SMITH*, S. E. HOLROYD, K. C .GORDON University of Otago, Dunedin, New Zealand Imaging Processed Cheese Components Using Raman Microscopy

R. BENFERHAT Horiba Instrument Pty Ltd, Singapore Latest development in Nano-Raman Spectroscopy and application to materials analysis

B. R. WOOD*, E. LIPEC, P. HERAUD, D. WHELAN, D. MCNAUGHTON, J. ZHANG, D. Y. PARKINSON, J. BIELECKI, W. M. KWIATEK, M. LEKKA, M. TOBIN, K. R. BAMBERY, C. B. ADIBA, G. DIETLER, A. KULIK, A. JAPARDIZE, F. S. RUGGERI Monash University, Australia DNA conformation and nuclear ultrastructure analysed with synchrotron FTIR, Soft X-ray Tomography, NanoIR and TERS

12.20 – 12.40 M. K. NIEUWOUDT*, S. E. HOLROYD, C. MCGOVERIN, M. C. SIMPSON, D. E. WILLIAMS The University of Auckland, Auckland, New Zealand Raman spectroscopy for rapid screening of nitrogen-rich adulterants in milk

I. BLAKEY*, P. DENMAN, M. SIAUW, K. JACK The University of Queensland, St. Lucia, Australia Surface Enhanced Raman Scattering Based Sensors for Small Molecules

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SESSION XV – MINEROLOGY/GEMMOLOGY

SESSION XVI – FORENSICS SESSION XVII – CHEMOMETRICS

CHAIR: D. COZZOLINO CHAIR: B. H. STUART CHAIR: P. LASCH 13.40 – 14.20 PLENARY LECTURE - L. KIEFERT

Gubelin Gem Lab Ltd., Luzern, Switzerland Spectroscopic Methods in Gemstone Testing

PLENARY LECTURE – M. LOGAN Queensland Fire and Emergency Services, Cannon Hill, Australia It is an emergency: Spectroscopy outside the laboratory

PLENARY LECTURE - A. G. RYDER*, B. LI, A. CALVET, C. MORRIS, Y. CASAMAYOU-BOUCAU National University of Ireland, Galway, Ireland Low-concentration Analyte Quantification in the Solid State Using Raman Spectroscopy and Chemometrics

14.20 – 14.40 S. SHARMA, T. RODEMANN*, G. DAVIDSON, D. R. COOKE University of Tasmania, Hobart, Australia Raman Mapping of Molybdenite in Graphitic Metasediments

B. J. RILEY*, V. SPIKMANS, C. LENNARD, S. FULLER University of Western Sydney, Penrith, Australia Evaluation of the Evidentiary Significance of Asphaltene Profiling for Application in Forensic Source Determination of Oil Spills

B. SWARBRICK*, F. WESTAD, G. R. FLAATEN, L. GIDSKEHAUG Quality by Design Consultancy, Petersham, Australia Assumption Free Modeling Approach for the Monitoring and Control of Batch Processes

14.40 – 15.00 C. LAUKAMP*, I.C. LAU, R. WANG CSIRO Mineral Resources, Kensington, Australia Tracing exchange vectors of minerals in hydrothermal systems using SWIR and TIR active functional groups

T. M. BEDWARD*, L. XIAO, S. FU University of Technology Sydney, Broadway, Australia Application of Raman Spectroscopy in the Detection of Cocaine in Food Matrices

M. ANDO*, S. YABUMOTO, H. HAMAGUCHI Waseda University, Tokyo, Japan Quantitative Raman Spectroscopy of Complex Systems by Hypothetical Addition Multivariate Analysis with Numerical Differentiation

15.00 – 15.20 M. A. WELLS*, E. R. RAMANAIDOU, J. BOURDET CSIRO, Kensington, Australia Raman Spectroscopic Characterisation of Al/Mg-Chromite Oxidation in New Caledonian Ni laterite

W. VAN BRONSWIJK*, M. MARIC, S. W. LEWIS Curtin University, Perth, Australia The Application of Infrared and Raman Spectroscopies to the Characterisation of Automotive Clear Coats for Forensic Purposes

E. LIPIEC, K. R. BAMBERY*, J. LEKKI, M. J. TOBIN, C. VOGEL, D. WHELAN, B. R. WOOD, W. M. KWIATEK Australian Synchrotron, Clayton, Australia Synchrotron FTIR microspectroscopy coupled with Principal Component Analysis shows evidence for the cellular bystander effect

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xviii

ACommercial presentations. Not scientifically reviewed

17.00 – 18.00 Poster Session 2 (see next page)

SESSION XVIII – EXHIBITORS SESSION XIX – BIOSPECTROSCOPY IV SESSION XX – ENVIRONMENTAL CHAIR: R. S. ARMSTRONG CHAIR: A. G. RYDER CHAIR: W. VAN BRONSWIJK 15.40 – 16.00 M. KRESS*, T. DIEING, S. LEE,

O. HOLLRICHER, U. SCHMIDT WITec GmbH, Ulm, Germany New generation Raman imaging: Confocal 3D Raman imaging meets highest spectral resolution

J. P. NUNN*, G. S. WALKER, K. P. KIRKBRIDE, N. E. I. LANGLOIS, D. APPADOO Flinders University, Adelaide, Australia Spectroscopic identification and analysis of haemoglobin components in bruises

J. J. LIN - INVITED Academia Sinica, Taipei, Taiwan Reactivity and Spectroscopy of Simple Criegee Intermediates and Implications in Atmospheric Chemistry

16.00 – 16.20 K. TAM*, A. BALES, G. ZACHMANN, M. JÖRGER2 Bruker Pty Ltd, Alexandria, Australia The reinvention of interleaved time-resolved FT-IR spectroscopy

A. DOWD*, E. A. CARTER, M. B. CORTIE, P. A. LAY University of Technology Sydney, Broadway, Australia Microstructural Investigation of Biogenic Carbonates in Mollusc Shells with Raman Spectroscopy

Y.-P. LEE*, Y.-H. HUNAG, L.-W. CHEN, Y.-I. WANG - INVITED National Chiao Tung University, Hsinchu, Taiwan Infrared Spectroscopy of Criegee Intermediates (CH2OO, CH3CHOO, and (CH3)2COO) and Iodoalkylperoxyl Radicals (ICH2OO)

16.20 – 16.40 R. BENFERHATA

Horiba Instrument Pty Ltd, Singapore Singapore Introduction to HORIBA Scientific

S. SUZUKI*, L. GRØNDAHL, E. WENTRUP-BYRNE Queensland Eye Institute, South Brisbane, Australia FTIR Spectroscopic Investigation of Phosphate Polymers for Biomedical Applications

G. SRINIVASULU, B. RAJAKUMAR* Indian Institute of Technology Madras, Chennai, India Measurement of absorption spectrum of the propionyl radical (CH3CH2CO) radical using Cavity Ring Down Spectroscopy (CRDS)

16.40 – 17.00 C. F. KONGA

PerkinElmer, Australia FTIR microscopy and Imaging

E. A. CARTER*, A. LEVINA, A. I. MCLEOD, A. SAFITRI, S. TARR, S. GASPARINI, J. LEONG, M. WOOD, P. A. LAY The University of Sydney, Australia Adipocytes: A Key to Unlocking the Secrets of Glucose Metabolism

A. BALES*, P. MAAS, A. GEMBUS Bruker Pty Ltd, Alexandria, Australia Measuring from a Distance - Remote Sensing By FTIR Technology

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xix

17.00 – 18.30 POSTER SESSION II PSII-1 K. M. SAFIANOWICZ*, T. BELL, M. KERTESZ

Spectroscopy of solid-state microbial fermentation: fingerprinting for button mushroom production PSII-2 A. TREASURE*, V. OTIENO-ALEGO, N.SMITH

FTIR and Raman analysis of Colonial medicine chest bottles held in the collection of the National Museum of Australia PSII-3 E. A. CARTER*, M. WOOD, S. J. KELLOWAY, N. KONONENKO, R. TORRENCE

Characterisation of Microscopic Organic Residues Preserved on Ancient Stone Tools using SR-FTIR Spectroscopy PSII-4 M. KAUR*, A. K. JAIN, H. MOHAN, P. S. SINGH, S. SHARMA

Vibrationally Elastic Cross-sections for Electron Interactions with Environmentally Related Methane Molecules PSII-5 J. E. HALSTEAD*, E. A. CARTER, J. A. SMITH, M. A. BROWNE, E. L. JOHNSTON

Getting to the ‘guts’ of plastic pollution: identification of ingested polymers PSII-6 L. XIAO*, M. SUDEN, N. KRAYEM, S. FU

Analysis of Cocaine Analogues Impregnated into Textiles by Raman Spectroscopy PSII-7 J. S. ROONEY*, A. MCDOWELL, C. J. STRACHAN , K. C. GORDON

Vibrational spectroscopic methods to identify and quantify adulterants in weightloss herbal medicines PSII-8 L. RINTOUL*, A. WORTHY, K. FISHER, J. BOUZAID, J. MCMURTRIE

Raman Mapping of Two Metal Ligand Co-crystals PSII-9 G. E. ROBERTS*, P. F. REY, E. A. CARTER

Raman spectroscopic study of inclusions in precious opals offer insights into Martian-like weathering processes PSII-10 H. LIU*, C. YANG

The current of the QDIP with illumination PSII-11 C. F. TIAN*, P. WANG, T. Y. XIE, Z. X.GAO, J. X. FANG

3D-FDTD Simulation of the Gold urchin-like nanopartilces for the spectral properties of Localized Surface Plasmon Resonance PSII-12 Q. Y. HAN*, C. Y. ZHANG, L. X. YAN, Z. L. ZHANG, E. J. HE, J. DONG, Z. J. WANG, H. R. ZHENG

In situ monitoring and detecting catalytic reaction with surface-enhanced Raman scattering PSII-13 C. H. HEATH*, B. PEJCIC, M. MYERS

Infrared characterisation of calixarene-polymer composite materials for surface modified ATR waveguides PSII-14 J. L. CAO*, Y. B. JIANG

Halogen Bonding Assisted Formation of Supramolecular Helical Structure with Chiral Amplification PSII-15 C. F. KONG

Polymer Recycling PSII-16 Y. YUAN*, X. S.YAN, Y. B. JIANG

β-Turn Based Ratiometric Fluorescent Beacon Receptor for Anion PSII-17 O. KRECHKIVSKA*, K. NAUTA, K. L. K. LEE, Y. LIU, S. H. KABLE, T. W. SCHMIDT

REMPI Spectroscopy of Toluene+H. Hydrogenation and Deuteration effects on Methyl Rotor PSII-18 M. KAUR*, H. MOHAN, A. K. JAIN, P. S. SINGH, S. SHARMA

Role of Multiple Ionization in L X-ray Fluoroscopic Spectrum of Platinum PSII-19 A. BALES*, K. TAM, G. ZACHMANN, M. KEßLER2

MIR-FIR Spectroscopy by a Single Step Data Acquisition PSII-20 R. S. SEOUDI*, A. DOWD, M. DEL BORGO, K. KULKARNI, P. PERLMUTTER, M.-I. AGUILAR, A. MECHLER

Terahertz spectroscopy of a supramolecular assembly: helical fibres of N-acetylated tri-β3-peptides

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xx

DAY 4 – FRIDAY, 2ND OCTOBER

10.40 – 11.00 Morning Tea

12.20 – 13.20 Lunch

SESSION XXI – ARCHEAOLOGY I SESSION XXII – ULTRAFAST AND NON-LINEAR SPECTROSCOPY II

CHAIR: L. KIEFERT CHAIR: K. IWATA 9.00 – 9..40 PLENARY LECTURE - B. H. STUART*, P. S. THOMAS,

A. HUNT, L. CHUA University of Technology Sydney, Broadway, Australia Shedding light on indigenous art: using vibrational spectroscopy to understand Australasian paint chemistry

PLENARY LECTURE - T. JOO POSTECH, Pohang, South Korea Molecular Reaction Dynamics in Condensed Phase by Extreme Time-Resolved Fluorescence

9.40 – 10.00 R. A. GOODALL*, D. MEASDAY Museum Victoria, Carlton, Australia The Identification of Coatings and Adhesives on Museum Victoria’s Palaeontology Collection using ATR - FTIR

H.-H. YAO, H.-H. CHENG, J.-S. YANG, I.-C. CHEN* - INVITED National Tsing Hua University, Hsinchu, Taiwan Dynamics of Excited States of Arylaminostilbene Derivatives

10.00 – 10.20 L. BORDES University of Wollongong, Wollongong, Australia Surface-Enhanced Raman Spectroscopy for detection of wood residues on stone artefacts by silver nanolayer covering: preliminary results on experimental grinding and scraping tools

T. TAKAYA*, M. SHINOHARA, G. MOHRI, K. IWATA - INVITED Gakushuin University, Tokyo, Japan Ultrafast Charge Separation Dynamics of Neutral π-Conjugate Systems in Solution Observed by Time-Resolved Near-IR Absorption and Stimulated Raman Spectroscopy

10.20 – 10.40 P. DREDGE*, L. PUSKAR, L. ALLEN, M. SAWICKI, R. WUHRER Art Gallery of New South Wales, Sydney, Australia Binders Used in Metallic Paints Investigated by Micro-FTIR and Synchrotron-sourced FTIR

F. NOVELLI, G. H. RICHARDS, A. ROOZBEH*, A. NAZIR, K. E. WILK, P. M. G. CURMI, J. A. DAVIS Swinburne University of Technology, Hawthorn, Australia Vibronic Resonances Enable Excited State Coherence in Light Harvesting Proteins at Room Temperature

SESSION XXIII – ARCHEAOLOGY II SESSION XXII (CONT.) – ULTRAFAST AND NON-LINEAR SPECTROSCOPY II

CHAIR: M. LOGAN CHAIR: T. JOO 11.00 – 11.20 E. NOAKE*, P. NEL, D. LAU

University of Melbourne, Australia FTIR-ATR identification of cellulose nitrate in museum collections: Middle Eastern archaeological pottery case study

S.-Y. LEE*, Y.C. WU, B. ZHAO - INVITED Nanyang Technological University, Singapore Time dependent Frequencies of Vibrations from Off-resonant Femtosecond Stimulated Raman Spectra

11.20 – 11.40 L. C. PRINSLOO*, R. FULLAGAR, M. W. MORLEY, S. LUONG, L. BORDES, E. HAYES, E. FLANNERY, T. SUTIKNA, R. ROBERTS University of Wollongong, Wollongong, Australia Vibrational Spectroscopy in the Stone Age: identification of residues on stone tools

Y. OHSHIMA - INVITED Tokyo Institute of Technology, Tokyo, Japan Coherent Nonlinear Optical Manipulation of Molecular Vibration and Rotation

11.40 – 12.00 E. BLAKE, T. D. MURPHY*, P. DREDGE, D. HINTON, C. LENNARD, V. SPIKMANS, R. WUHRER University of Western Sydney, Penrith, Australia Analysis of Polymer Art Works for Restoration and Optimise Storage Conditions

K. IWATA - INVITED Gakushuin University, Tokyo, Japan Weak Molecular Interaction in Condensed Phases Examined with Time-resolved spectroscopies - Raman and Near-Infrared Absorption

12.00 – 12.20 W. J. READE*, E. A. CARTER, M. ALLON The University of Sydney, Australia Identification of the Coating on the Marble Buddhist Inscriptions of the Kuthodaw Pagoda Complex, Myanmar (UNESCO Memory of the World Register)

J. WANG, M. XU, Z. HUANGFU, Y. WANG, Y. HE, W. GUO, Z. WANG* Xiamen University, Xiamen, China Sum-Frequency Generation Spectroscopy of Thiocyanate Oxidation on Polycrystalline Au Surface

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xxi


16.00 – 16.15 STUDENT PRIZES 16.15 – 16.30 CLOSING REMARKS

SESSION XXIV – MAPPING AND IMAGING SESSION XXV – SYNCHROTRON III CHAIR: P. A. LAY CHAIR: D. MCNAUGHTON 13.20 – 13.40 PLENARY LECTURE - P. LASCH*, M. STÄMMLER, M. ZHANG,

K. MAJZNER Robert Koch-Institute, Berlin, Germany FTIR Hyperspectral Imaging for Rapid Identification of Pathogenic Microorganisms

E. G. ROBERTSON*, A. WONG, C. MEDCRAFT, M. RUZI, D. MCNAUGHTON, D. APPADOO LaTrobe University, Australia Heavy snow: IR spectroscopy of isotopically diluted water ice particles

13.40 – 14.00 J. TAMMARO, O. PIRALI, G. MOURET, F. HINDLE, A. CUISSET, J-F. LAMPIN, G. DUCOURNAU, E. ROUSSEL, C. SZWAJ, C. EVAIN, S. BIELAWSKI, L. MANCERON, J. B. BRUBACH, M. A. TORDEUX, M. E. COUPRIE, P. ROY* SOLEIL Synchrotron, France THz coherent Synchrotron Radiation used for Ultra High resolution Spectroscopy and Ultra-fast THz measurements

14.00 – 14.20 C. AUSTIN*, T. M. SMITH, E. A. CARTER, J. LEE, P. A. LAY, B. J. KENNEDY, M. ARORA The University of Sydney, Australia Mapping Signals of Early Life Stress Events in Teeth Using Raman Spectroscopy

S. P. GNANSEKAR, M. GOBET, R. GEORGES, E. ARUNAN* Indian Institute of Science, Bangalore, India Molecular Beam Microwave Spectroscopy and Slit-jet IR Spectroscopy: From carbon bond to gas phase nucleation

14.20 – 14.40 A. RAJKUMAR*, G. L. CLARE, J. C. AITCHISON, E. A. CARTER The University of Sydney, Australia Clues to UHPM — using Raman spectroscopy and mineral equilibria modelling to examine pressure variation in UHP garnet from Dabie Shan and Tso Morari eclogites

F. WANG*, S. BEST, C. CHANTLER, S. ISLAM, T. ISLAM, R. TREVORAH, D. APPADOO Swinburne University of Technology, Australia Temperature and environmental effects on the IR spectra of ferrocene – The meeting place of experiment and theory

SESSION XXVI – NEUTRON SPECTROSCOPY SESSION XXVII – PLASMONICS II CHAIR: P. R. STODDART CHAIR: B. REN 15.00 – 15.20 A. STAMPFL

ANSTO, Lucas Heights, Australia Vibrational neutron spectroscopy on organic and inorganic molecules

Q.-H. XU - INVITED National University of Singapore, Singapore Aggregation Enhanced Two-Photon Photoluminescence of Metal Nanoparticles

15.20 – 15.40 D. H. YU*, G. J. KEARLEY, G. F. LIU, R. A. MOLE, X. T. TAO ANSTO, Lucas Heights, Australia On the phase-transition mechanism of CuQ2-TCNQ molecular crystals

J. YI, S.-Y. DING, Z.-Q. TIAN* - INVITED Xiamen University, Xiamen, China Toward Plasmonic Fano-resonance Enhanced Spectroscopy: From Raman to Infrared Scattering

15.40 – 16.00 R. RUSSELL*, T. DARWISH, P. HOLDEN, L. JOHN, R. FOSTER ANSTO, Lucas Heights, Australia Deuterium labelling at Australia’s National Deuteration Facility: Characterization of Biopolymer Nanocomposite Systems using Infrared Microspectroscopy

J.-H. ZHONG*, X. WANG, B. REN Xiamen University, Xiamen, China Tip-Enhanced Raman Spectroscopy Study on Bimetallic Catalyst Surfaces

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WITHDRAWN

ACOVS11/ASC5 Book of Abstracts Keynote Lecture

1

KEYNOTE LECTURE


2

Bridging Molecular Dynamics and Resonance Raman Spectroscopy to Highlight the Structural Properties of Bacterial Hemoglobins G. SMULEVICH Dipartimento di Chimica “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3-13,50019 Sesto Fiorentino (Fi), Italy [email protected]

The first observation of hemoglobins (Hbs) in microorganisms was made by Warburg in the 1930s and reported, 20 years later by Keilin, who assigned the oxygen dependent hemoglobin-like absorption bands in moulds, fungi and protozoa [1]. It is now known that Hbs are present in organisms from virtually all kingdoms. Based on sequence alignment, three groups of Hbs have been characterized in unicellular organisms. Among them, the group called truncated hemoglobins (TrHbs) consists of proteins with 110–140 amino acid residues and a novel two-over-two α-helical sandwich motif. TrHbs are widely distributed in bacteria, archaea and plants and are also found in some unicellular eukaryotes. They display less than 20% overall identity with respect to the 3-on-3 animal Hbs, and are classified into three groups, designated I (trHbN), II (trHbO) and III (trHbP) [2]. Unlike the Hb of vertebrates, which is an oxygen carrier that transports oxygen to local tissues through the vascular system, the highly polar distal heme pocket of TrHbs from unicellular organisms results in a very tight oxygen bond.

In this presentation, the combination of resonance Raman (RR), electronic absorption and molecular dynamics (MD) simulation for two members of the group II (trHbO) will be presented. The results will be discussed in the context of the structural and functional properties since the physiological role of most microbial globins remains unknown. In particular, the TrHbs from the thermophilic actinobacterium Thermobifida fusca and that from Pseudoalteromonas haloplanktis TAC125, a cold-adapted Antarctic marine bacterium will be compared. The aim of the study has been to understand the structural parameters that lead to thermostability and the behavior of the highly reactive heme moiety towards heat stress (T. fusca) and to the ability of an organism to survive and grow in the cold (P. haloplanktis).

Over the past several decades resonance Raman spectroscopy has been extensively applied to the study of structure, function, folding, and dynamics of heme proteins [3]. In general, the combined analysis of electronic absorption and RR spectra enables some general conclusions to be obtained. The electronic absorption spectrum is characterized by the π→π* electronic transitions in the Soret (380-440 nm) and visible Q bands (500-600 nm) regions deriving from the heme chromophoric group [4]. In addition, high spin (HS) ferric heme proteins show also weak bands assigned to porphyrin to iron charge transfer transitions in the 450-470 nm (CT2) and 600-650 nm (CT1) regions [5]. When heme proteins are excited with a laser wavelength coincident with these electronic transitions, only the Raman spectrum of the heme moiety is enhanced. In particular, excitation in the Soret and Q bands leads to the intensification of the heme vibrational modes; moreover, in resonance with the Soret transition and/or by excitation in the CT bands, Fe-Ligand stretching modes in the low frequency region of the RR spectrum are intensified. Therefore, vibrational spectroscopy offers a powerful tool since interactions of ligands with the protein side-chains that line the heme pocket are critical for discriminating among the binding of the various ligands, and for regulating the subsequent protein conformational changes or the ligand reactivity. Steric contacts can prevent ligand binding or induce slight distortions of the porphyrin ring geometry thus modifying the Fe-ligand electronic properties; polar and hydrogen-bond interactions with side-chains distal to the bound ligand can polarize the Fe-ligand bond. To highlight the physical and chemical properties of heme protein functions is fundamental to gain an understanding of these interactions. Since the iron-ligand stretching frequency is strongly modulated by the interactions between the ligand and the surrounding amino acids, information on the role of the heme cavity residues in ligand stabilization and the hydrogen bonding network lining the proximal and distal sides of the heme can be obtained. Moreover, computer simulation provides an important tool to complement the experimental studies. In fact, the hydrogen bond network of truncated hemoglobins is dynamic and several conformations can be considered; in particular, we focus our attention on the interactions between distal site residues and the ligand coordinated to the heme iron. Furthermore, comparison of single point mutants performed in-silico also helps to clarify the individual residue contributions to ligand affinity.

The TrHb from T. fusca is one of the most extensively studied truncated hemoglobins, both in terms of spectroscopic and molecular dynamics studies. Its active site is characterized by a highly polar distal environment in which TrpG8, TyrCD1, and TyrB10 provide three potential H-bond donors in the distal cavity capable of stabilizing the incoming ligands. The role of these residues in key topological positions, and their interplay with the iron-bound ligands, has been addressed in studies carried out on the CO, F-, OH-, CN-, and HS- adducts formed with the wild-type protein and a combinatorial set of mutants, in which the distal polar residues, TrpG8, TyrCD1, and TyrB10, have been singly, doubly, or triply replaced by a Phe residue. In this context, such a complete analysis provides an excellent benchmark for the investigation of the relationship between protein structure and function, allowing one to translate the physico-chemical properties of the active site into the observed functional behaviour. The subtle features observed for each Fe-ligand complex account for the observed differences in ligand binding behaviour. The body of experimental observations and MD simulations indicate that a multiplicity of interactions modulate the properties of Fe-ligand moieties in this truncated hemoglobin and, hence, dominate the dynamics of ligand entry and escape and possibly also modulate ligand stabilization [6-12].

The analysis of the crystal structure of the TrHb from P. haloplanktis revealed that in common with T. fusca, in the distal cavity a TrpG8 and a TyrB10 are conserved, while the CD1 topological position is occupied by a His [13].


3

Interestingly, the TrHb from P. haloplanktis shares only a few common features with T. fusca and the overall data depict a flexible architecture in its heme pocket, rarely reported for other globins [13-16]. The results highlight the unique adaptive structural properties of the protein that enhance its overall flexibility, as recently demonstrated by its resistance to pressure-induced stress [17]. Although some of these adaptive mechanisms are undoubtedly species-specific, the remarkable access of the TrHb from P. haloplanktis to unusual conformations may represent a molecular property encoded in the TrHb group II structure to face the dynamic and functional requirements posed by the Antarctic environment.

Taken together, these results highlight the considerable potential afforded by the combination of RR spectroscopy and MD simulations, which can provide complementary microscopic insight, to widen our understanding on the complex interactions that modulate the relationship between structure and reactivity in this important group of proteins. Hydrogen bond stabilization plays the main role in ligand binding, and it is clear that the unique structural features of these proteins are optimized to perform functions different from oxygen transport. Acknowledgement I acknowledge all members of my research group and all co-workers who are responsible for some of the work reviewed in this presentation; their names are listed in the appropriate references. References [1] D. Keilin, Nature, 172, (1953), 390-393. [2] S. Vinogradov, M. Tinajero-Trejo, R. K. Poole, D. Hoogewijs, Biochim Biophys Acta 1834, (2013), 1789–1800. [3]T.G. Spiro, (Ed.); Biological Applications of Raman Spectroscopy: Resonance Raman Spectra of Hemes and Metalloproteins,

Vol. 3 Wiley, New York (1988) [4] M. Gouterman, In The Porphyrins; Volume III, D. Dolphin, D (Ed.), Academic Press, New York (1978), 1–165. [5] F. Adar, The Porphyrins; Volume III, D. Dolphin, D (Ed.), Academic Press, New York (1978), 167–209. [6] F.P. Nicoletti, A. Comandini, A. Bonamore, L. Boechi, F. M. Boubeta, A. Feis, G. Smulevich, A. Boffi, Biochemistry, 49,

(2010), 2269-2278. [7] E. Droghetti, F. P. Nicoletti, A..Bonamore, L..Boechi, P. Arroyo-Manez, D. A. Estrin, A. Boffi, G. Smulevich, A. Feis,

Biochemistry, 49,( 2010), 10394-10402 [8] E Droghetti, F. P. Nicoletti, A. Bonamore, N. Sciamanna, A. Boffi, A. Feis, G. Smulevich, J. Inorg. Biochem.,105, (2011), 1338-

1343. [9] F. P. Nicoletti, E. Droghetti, L. Boechi, A. Bonamore, N. Sciamanna, D. Estrin, A. Feis, A. Boffi, G. Smulevich, J. Am. Chem.

Soc., 133, (2011) 20970-20980. [10] F. P. Nicoletti, E. Droghetti, B. D Howes, J. P Bustamante, A. Bonamore, N. Sciamanna, D. A Estrin, A. Feis, A. Boffi, G.

Smulevich BBA - Proteins and Proteomics, 1834, (2013) 1901-1909.

[11] L. Capece, L. Boechi, L. L Perissinotti, P. Arroyo-Manez, D. E Bikiel, G. Smulevich, M. A Marti, D. A. Estrín, BBA - Proteins and Proteomics 1834, (2013),1722-1738.

[12] F. P. Nicoletti, J. P. Bustamante, E. Droghetti, B. D. Howes, M. Fittipaldi, A. Bonamore, P. Baiocco, A. Feis, A. Boffi, D. A. Estrin, G. Smulevich, Biochemistry 53, (2014), 8021−8030.

[13] D. Giordano, A. Pesce, L. Boechi, J.P. Bustamante, E. Caldelli, B. D. Howes, A. Riccio, G. di Prisco, M. Nardini, D. Estrin, G. Smulevich, M. Bolognesi, C. Verde, Febs J. (2015), in press.

[14] B. D. Howes, D. Giordano, L. Boechi, R. Russo, S. Mucciacciaro, C. Ciaccio, F. Sinibaldi, M. Fittipaldi, M. A. Martì, D. A. Estrin, G. di Prisco, M. Coletta, C. Verde, G. Smulevich, J. Biol. Inorg. Chem., 16, (2011), 299-311.

[15] A. Merlino, B.D. Howes, G. di Prisco, C. Verde, G. Smulevich, L. Mazzarella, A. Vergara, IUBMB Life, 63, (2011), 295-303. [16] D. Giordano, R. Russo, C. Ciaccio, B. D. Howes, G. di Prisco, M. C. Marden, G. Hui Bon Hoa, G. Smulevich, M. Coletta, C.

Verde, IUBMB Life, 63, (2011), 566-573. [17] R- Russo, D. Giordano, G. di Prisco, G. Hui Bon Hoa, M. C. Marden, C. Verde, L. Kiger, Biochim Biophys Acta 1834, (2013), 1932–1938.

Fig. 1. UV-Vis and RR spectra of wild-type T. Fusca TrHb at different pHs. The corresponding MD simulations at pH 6.1 and 10.1 are also reported [10].

ACOVS11/ASC5 Book of Abstracts Plenary Lectures

4

PLENARY LECTURES


5

Infrared Spectroscopy in 3D and at Nano Scales M. C. MARTIN1*, H. A. BECHTEL1, D. Y. PARKINSON1, M. J. NASSE2, C. J. HIRSCHMUGL3, E. A. MULLER4,5, R. L. OLMON4,5 AND M. B. RASCHKE4,5 1Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA USA 2Laboratory for Applications of Synchrotron Radiation, Karlsruhe Institute of Technology, Karlsruhe, Germany 3Physics Department, University of Wisconsin–Milwaukee, Milwaukee, Wisconsin, USA

4Departments of Physics and Chemistry, University of Colorado, Boulder, CO 80309

5JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309 Synchrotron infrared beamlines use the diffraction-limited beam properties to enable a variety of cutting edge

science at the micron length scale in both reflection and transmission. It has enabled a wide variety of users to perform science across numerous fields. In this talk, I will explore how can we go further?

I will describe two new techniques we have recently developed and demonstrated. First, 3D FTIR tomography [1] provides spectrally rich, label-free, non-destructive visualizations of distinctive chemical compositions throughout intact biological or materials samples. The technique has combined Fourier Transform Infrared (FTIR) spectroscopy with computed tomography (CT) to create a non-destructive 3D imaging technique that provides molecular-level chemical information of unprecedented detail on biological and other specimens with no need to stain or alter the specimen. We are installing a new IR imaging and tomography endstation at beamline 2.4 of the Advanced Light Source (ALS). I will describe how the technique works and present application examples spanning a variety of scientific disciplines.

Second, by combining scattering-scanning near-field optical microscopy (s-SNOM) with mid-infrared synchrotron radiation, Synchrotron Infrared Nano-Spectroscopy (SINS) enables molecular and phonon vibrational spectroscopic imaging, with rapid spectral acquisition, spanning the full mid-infrared (500-5000 cm-1) region with nano-scale spatial resolution [2]. This highly powerful combination provides access

to a qualitatively new form of nano-chemometric analysis with the investigation of nanoscale, mesoscale, and surface phenomena that were previously impossible to study with IR techniques. We have installed a SINS end-station at Beamline 5.4 at the ALS at Lawrence Berkeley National Laboratory, making the s-SNOM technique widely available to non-experts, such that it can be broadly applied to biological, surface chemistry, materials, or environmental science problems. We demonstrate the performance of synchrotron infrared nano-spectroscopy (SINS) on semiconductor, biomineral and protein nanostructures, providing vibrational chemical imaging with sub-zeptomole sensitivity.

Acknowledgement The ALS is supported by the Director, Office of Science, Office of Basic Energy Sciences, and the BSISB is supported by the Office of Biological and Environmental Research, all through the U. S. Department of Energy (DOE) under Contract No. DE-AC02-05CH11231. M.R. acknowledges supported by the U. S. DOE, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award No DE-FG02-12ER46893. References [1] Michael C. Martin, Charlotte Dabat-Blondeau, Miriam Unger, Julia Sedlmair, Dilworth Y. Parkinson, Hans A. Bechtel, Barbara Illman, Jonathan M. Castro, Marco Keiluweit, David Buschke, Brenda Ogle, Michael J. Nasse, Carol J. Hirschmugl, Nature Methods, 10, 861-864 (2013). [2] Hans A. Bechtel, Eric A. Muller, Robert L. Olmon, Michael C. Martin, Markus B. Raschke, Proceedings of the National Academy of Sciences, 111(20), 7191–7196 (2014).

Figure 1. Spectro-microtomographic images of a human hair show absorptions of protein (red) and phospholipid (blue-green). Center, the medulla is observed to have little protein. Bottom, the medulla has higher concentrations of phospholipids.

Figure 2. This peptoid nanosheet, produced by Gloria Olivier and Ron Zuckerman at Berkeley Lab, is less than 8 nanometers thick at points. SINS makes it possible to acquire spectroscopic images of these ultra-thin nanosheets for the first time.

Figure 3. Experimental setup for SINS that includes the synchrotron light source, an atomic force microscope, a rapid-scan Fourier transform infrared spectrometer, a beamsplitter, mirrors and a detector.


6

Surface- and Tip-Enhanced Raman Spectroscopy from Mechanism to Applications K. Q. LIN1, B. J. LIU1, C. ZONG1, X. WANG1, W. SHEN1, Z. C. ZENG1, B. REN1*

1State Key Laboratory of Physical Chemistry of Solid Surfaces, MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Collaborative Innovation Center of Chemistry of Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China e-mail: [email protected]

It is known that the major contribution to surface-enhanced Raman spectroscopy (SERS) as well as tip-enhanced

Raman spectroscopy (TERS) is the localized surface plasmon resonance (LSPR) of plasmonic nanostructures. Although it has been most frequently assumed in the literature that the SERS/TERS enhancement approximately equals the fourth power of the electric field (E4), an in-depth understanding of the enhancement mechanism requires a more detailed understanding of the meaning of E in the expression. The simplest example is on the origin of the background of SERS and TERS, which is still in debate. We demonstrated with well controlled single nanorods experiment that the inevitable background is indeed not from the fluorescence of dye molecule or the surface impurities, instead it shares a similar enhancement mechanism of SERS and TERS. It is not from the molecule but from the photoluminescence of the metallic nanostructure. With this understanding, we proposed a way to correct the relative Raman intensity of molecular species with the SERS background and bulk photoluminescence, which is able to remove the influence of plasmon shaping effect and allows us to recover the original Raman spectra. In this way, the corrected Raman spectra can faithfully reflect the chemical interaction of the molecules with the substrate. This result clearly indicates that the relative intensity in the SERS or TERS is shaped by the emission pattern of the plasmonic system. On the other hand, the SERS overall enhancement is affected more significantly by the excitation electric field, which is dominated by the local near field strength of the plasmonic nanostructure. Only when the molecule is located at the position with highly enhanced near field, will the Raman signal be significantly enhanced. With this understanding, it seems the SERS background becomes the fundamental noise limit of SERS. We then explored a way to suppress the background but retain a high SERS enhancement, which is of important implication to practical SERS applications.

We further proposed a time-resolved SERS measurement strategy for probing analytes with ultralow surface concentration to effectively eliminate the background noise and improve the detection sensitivity. Only when a molecule enters into the enhanced region, it will produce the signal. However, when the molecule is outside the enhanced region, only the noise instead of the signal can be detected. As a result, the SERS spectrum obtained by a long exposure time contains two parts of contribution: signal (signal plus background noise, when the molecule is in the enhanced region) and noise (when the molecule is outside the enhanced region). But if we shorten the exposure time, we may be able to selectively detect the signal and discard the noise to improve the signal to noise ratio. In this way, the detection sensitivity of ultralow concentration analytes can be significantly improved by shortening the spectra acquisition time.

Another way to improve the detection sensitivity is to enhance the interaction of probe molecules with the metal nanoparticles. We were able to achieve reliable label-free detection of protein and protein mixtures, as well as DNA molecules with single-base sensitivity. To deal with the quantitative analysis issue, we further developed core-molecule-shell nanoparticles (CMS NPs) with two components in the molecular layer, a framework molecule to form the shell and a probe molecule as Raman internal standard, for the quantitative SERS analysis. The signal of the embedded Raman probe provides an effective feedback to correct the fluctuation of samples and measuring conditions. Meanwhile, the shell can be completely adsorbed by target molecules with different affinities. This method allows the quantitative analysis of target molecules over a large concentration range.

Another way to improve the spectral quality is to use technique with a high spatial resolution, like TERS. The high spatial resolution allows extraction of signals from the “some molecules” or even “single molecules” by significantly lowering the background averaged signal. We further demonstrate how TERS allows us to obtain the dynamic process at the single molecule level. We will also introduce our recent progress related to electrochemical TERS. Acknowledgement Financial supports from MOST (2013CB933703 and 2011YQ03012406), NSFC (21227004, 21321062, J1310024, 21021120456) and MOE (IRT13036) are highly acknowledged. References [1] K. Q. Lin, J. Yi, S. Hu, B. J. Liu, J. Y. Liu, Z. C. Lei, X. Wang, J. Aizpurua, R. Esteban, B. Ren, in preparation [2] G. T. Boyd, Z. H. Yu, Y. R. Shen, Phys. Rev. B, 33(1986), 7923–7936. [3] L. J. Xu, Z. C. Lei, J. X. Li, C. Zong, C. Y. Yang, B. Ren, J. Am. Chem. Soc, 137 (2015)5149−5154. [4] W. Shen, X. Lin, C. Jiang, C. Li, H. X. Lin, J. Huang, S. Wang, G. K. Liu, X. M. Yan, Q. L. Zhong, B. Ren, Angew. Chem. Int.

Ed., 54 (2015) 7308 –7312. [5] B. J. Liu, K. Q. Lin, S. Hu, X. Wang, Z. C. Lei, H. X Lin, B. Ren, Anal. Chem., 87(2015)1058–1065.

Fig. 1. Recovering the intrinsic chemical information (right panel) from the original SERS spectra (left panel) of the same molecule on different Au nanorods.


7

Bio-Raman spectroscopy: A Bridge between Pathological Research and Clinical Diagnosis of Disease A. G. SHEN1, X. D. ZHOU1 AND J. M. HU1*

1Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China [email protected]

As a vibrational spectroscopic technique, Raman spectroscopy is sensitive to the structural and conformational changes of biomolecules. Currently, the structural and conformational changes of biomolecules within tissue may initiate pathological changes and occur as a result of the development of the disease. Most biomolecules, such as proteins, lipids, nucleic acids and chromophoric-molecules, exhibit sharp features of Raman spectra. These Raman bands are characteristic for specific structures and conformations of biomolecules within tissues and cells, and provide more specific molecular information about normal and diseased tissue. As a rapid, nondestructive and noninvasive technique, Bio-Raman spectroscopy is widely used in pathological research and clinical diagnosis [1].

In general, single Raman band of characteristic biomolecule is used as Raman marker for diagnosis of diseased tissue. But only one Raman marker can’t be satisfactorily used for pathological research and clinical diagnosis of tissue. My group developed a “Raman beacon” for diagnosis of diseased tissue. The Raman beacon is consisted of two or more Raman marker bands of two or more biomolecules in tissue. The use of Raman beacon increases greatly the sensitivity and specificity of diagnosis of diseased tissue.

Till now, my group has used Raman beacon to develop a series of Bio-Raman spectroscopic studies of organic tissues and cells and to realize pathological research and early, nondestructive and noninvasive of significant diseases. We use this method for pathological research of Alzheimer’s disease, pterygium, tooth discoloration, spinal injury, liver injury, tumors of oral cavity, bladder and upper gastrointestinal tract early diagnosis of Alzheimer’s disease and gastric cancer, differential diagnosis among Alzheimer’s disease, Parkinson’s disease and vascular dementia. In combination with morphological evaluation tests, we employ Bio-Raman spectroscopy and Raman beacon methodology to select higher potentially reproductive embryos during in vitro fertilization (IVF) based on chemical composition of embryos culture medium. With the help of optical tweezers, we also realize real-time molecular profiling of photochemically induced rat thrombosis in vivo through Raman analysis of both arterial and venous blood. Acknowledgement We thank for the financial support from National Natural Science Foundation of China (81471696, 21475100, 21175101 and 41273093), National Major Scientific Instruments and Device Development Project (2012YQ16000701) and Foundation of China Geological Survey (12120113015200), and the Fundamental Research Funds for the Central Universities (2042014kf0260). References [1] P. Chen, A. G. Shen, X. D. Zhou, J. M. Hu, Anal. Methods, 3 (2011), 1257-1269.


8

Gas Phase Spectroscopy of Neurotransmitters and Partial Peptides of Receptor by IR-UV Double Resonance Spectroscopy M. FUJII Chemical Resources Laboratory, Tokyo Institute of Technology, R1-15, 4259 Nagatsutacho, Midori-ku, Yokohama, 226-8503, Kanagawa, Japan [email protected]

A supersonic jet - laser spectroscopy is a powerful tool to study structures and dynamics of molecules and molecular clusters in the ground, excited and ionic states. Particularly the IR spectra obtained by IR-UV double resonance spectroscopy directly give the structural information with help of quantum chemical calculations. However, application to biomolecules and supramolecules is limited because these molecules are nonvolatile and are easily destroyed by pyrolysis with simple heating. Recently, this problem has been solved by the laser desorption of graphite matrix (see Fig. 1) [1] or the electrospray with cold ion trap techniques [2]. Here, the UV and IR spectroscopy of catecholamines and the partial peptide of the receptor obtained by the laser desorption technique will be presented.

Neurotransmitters such as adrenaline, dopamine and DOPA (see Fig. 3) [3] are molecules that are used to transfer signals in nerves. When neurosystem works, the neurotransmitters are emitted in synapse and recognized by a specific receptor. Because of its high selectivity, this molecular recognition is called as ‘a lock and a key’. However, all the neurotransmitters are flexible molecules with single bonds that are possible to take various forms. It is not straightforward why such a soft molecule can work as a key: a key should be sold in our daily life.

The first step to understand the molecular recognition by such soft molecules is to know their intrinsic, possible conformations. From this motivation, we have been studied the number of conformations and structures in neurotransmitters (catecholamines) and related molecules by the laser-desorption supersonic jet spectroscopy combined with REMPI and UV-UV Hole-Burning (HB) spectroscopy and IR dip spectroscopy.

Principle of HB spectroscopy is shown in the left panel of Fig. 2. The frequency of the probe laser νp is fixed to a specific band in the REMPI spectrum which corresponds to a UV absorption. The burn laser νb is introduced before νp and scans over the S1 region. When νb is resonant to the transitions originated from the conformer that νp is fixed, the ion current due to the resonant enhanced two-photon ionization of νp decreases because of the decrease of the ground state population. Thus the UV transition of a single conformer can be measured by the decrease of the ion current (HB spectrum). For tyrosine (right panel in Fig. 2)[4], 12 different HB spectra are observed and all the bands observed in the REMPI spectrum are found in the HB spectra. It means that tyrosine has 12 conformers even under the low temperature in a jet. On the other hand, only a single conformer is found in DOPA (see Fig. 3). Such smaller number of conformers in comparison with their analogue are found all of catecholamines.

In the presentation, systematic survey of conformations will be shown and the specific conformational reduction in the catecholamine will be discussed. The spectroscopy of SIVSF penta-peptide, which is the receptor pocket of b2- adrenaline receptor, will also be discussed. Acknowledgement This work is the collaboration with Prof. Shun-ichi Ishiuchi in Chemical Resources Laboratory, Tokyo Institute of Technology. This study was supported by MEXT (innovative area 2503 Japan). References [1] H. Mitsuda, et al.,JPCL., 1, 1130(2010) and references there in. S. Ishiuchi et al., PCCP. 13, 7812 (2011). [2] O. Boyarkin et al., JACS. 128, 2816 (2006). [3] S. Ishiuchi et al., PCCP. 13, 7812 (2011). [4] Y. Shimozono et al., PCCP. 15, 5163 (2013).

Fig. 1. Experimentaln setup for the laser desorption supersonic jet laser spectroscopy

Fig. 2. Principle of hole-burning (HB) spectroscopy (left) and REMPI and HB spectra of tyrosine molecule in a supersonic jet. HB spectra show that tyrosine has 12 conformers.

Fig. 3. REMPI and HB spectra of DOPA. Only a single conformer is found in spite of its flexible structure.


9

Ultrafast X-ray liquidography and crystallography capture molecular structural dynamics H. IHEE Center for Nanomaterials and Chemical Reactions, IBS, Daejeon 305-701, South Korea [email protected] Department of Chemistry, KAIST, Daejeon 305-701, South Korea

The pump-probe X-ray diffraction and scattering techniques have now been fully established as a powerful method to investigate molecular structural dynamics [1-5]. We have employed the techniques to study structural dynamics and spatiotemporal kinetics of many molecular systems including diatomic molecules, haloalkanes, organometallic complexes and protein molecules over timescales from ps to milliseconds. X-ray crystallography, the major structural tool to determine 3D structures of proteins, can be extended to time-resolved X-ray crystallography with a laser-excitation and X-ray-probe scheme, but has been limited to a few model systems due to the stringent prerequisites such as highly-ordered and radiation-resistant single crystals. These problems can be overcome by applying time-resolved X-ray diffraction directly to protein solutions rather than protein single crystals. To emphasize that structural information can be obtained from the liquid phase, this time-resolved X-ray solution scattering technique is named time-resolved X-ray liquidography (TRXL) in analogy to time-resolved X-ray crystallography where the structural information of reaction intermediates is obtained from the crystalline phase. We will present our recent results including the achievement of femtosecond TRXL by using an X-ray free electron laser. References [1] “Direct observation of bond formation in solution with femtosecond X-ray scattering”, K. H. Kim, J. G. Kim, S. Nozawa, T. Sato, K. Y. Oang, T. W. Kim, H. Ki, J. Jo, S. Park, C. Song, T. Sato, K. Ogawa, T. Togashi, K. Tono, M. Yabashi, T. Ishikawa, J. Kim, R. Ryoo, J. Kim, H. Ihee*, S. Adachi, Nature, 2015, 518, 385-389. [2] “Volume-conserving trans-cis isomerization pathways in photoactive yellow protein visualized by picosecond X-ray crystallography”, Y. O. Jung, J. H. Lee, J. Kim, M. Schmidt, K. Moffat, V. Srajer, H. Ihee*, Nat. Chem., 2013, 5, 212-220. [3] “Visualizing Solution-Phase Reaction Dynamics with Time-Resolved X-ray Liquidography”, H. Ihee*, Acc. Chem. Res., 2009, 42, 356-366 (Review Article). [4] “Tracking the structural dynamics of proteins in solution using time-resolved wide-angle X-ray scattering”, M. Cammarata*, M. Levantino, F. Schotte, P. A. Anfinrud, F. Ewald, J. Choi, A. Cupane, M. Wulff, H. Ihee*, Nat. Methods, 2008, 5, 881-887. [5] “Ultrafast X-ray diffraction of transient molecular structures in solution”, H. Ihee*, M. Lorenc, T. K. Kim, Q. Y. Kong, M. Cammarata, J. H. Lee, S. Bratos, M. Wulff, Science, 2005, 309, 1223-1227.

Fig. 1. Femtosecond TRXL has captured the formation of chemical bond in a gold trimer complex, [Au(CN)2

-]3 in solution.


10

Terahertz Spectroscopy of Proteins, Peptides and their Respective Hydration Layers R. J. FALCONER1*, V.P. WALLACE2, J. A. ZEITLER3, S. UDDIN4 AND C. F. VAN DER WALLE4

1University of Sheffield, Mappin Street, Sheffield S1 3JD, South Yorkshire, United Kingdom [email protected] 2University of Western Australia, Crawley, 6009, WA, Australia 3University of Cambridge Street No., Cambridge, CB2 3RA, Cambridgeshire, United Kingdom 4MedImmune, Grant Park, Cambridge, CB21 6GH, Cambridgeshire, United Kingdom

THz spectroscopy (THS) can detect the secondary structure of peptides using frequencies between 300-500 cm-1.[1] Below 300 cm-1 the spectra are complex but data-rich and worthy of further work. Analysis of peptides and proteins in aqueous conditions at physiological temperatures is confounded by the relatively high absorbance of the water compared to the protein. To see peptide resonances between 0-500 cm-1 the water absorbance needs to be negated by either freezing or drying the sample. While THS is capable of detecting secondary structure in peptides it is unlikely to be widely used for this application as existing techniques like circular dichroism spectroscopy are widely used for this application.

Early work using Terahertz time-domain spectroscopy (THz-TDS) with small synthetic peptides in solution noted a non-linear drop in absorbance with increased peptide concentration that plateaued at ~25 mM which was consistent with a hydration layer around 11-17 Å thick.[2] This finding supported the finding of Martina Havenith’s group for an extended hydration layer around proteins. Later we confirmed this observation using bovine serum albumin (BSA) as the analyte and THS using the Diamond Light Source operating in a low alpha mode to generate coherent synchrotron radiation that covered a useable spectral bandwidth of 0.3-3.0 THz (10-100 cm-1).[3] Using an overlapping hydration layer model the hydration layer was estimated to extend 15 Å from the protein and provided evidence for complexity in the population of water around this protein. While this finding is consistent with previous research it does ask the question of what are we observing and is it relevant to the properties of the protein.

Most recently THz-TDS was used to detect overlapping extended hydration layers around antibodies and deliberately modulate the hydration layer with small molecules like arginine, proline and sucrose. Changes were detected in the extended hydration layer by THz-TDS but were not translated to shifts in the thermal stability or protein interactions measured by differential scanning calorimetry and dynamic light scattering, respectively.

The challenge is still there to determine how information gleaned by THS can be used to better understand protein structures, the relationship between proteins, water and small cosolutes.

Acknowledgement We thank Prof. Anton Middelberg, Dr Tao Ding, Dr Thomas Huber, the Australian Synchrotron for access to their infrared beam-line, Dr Dominique Appadoo for his assistance, Prof. David Fairlie for the KARAD peptides and MedImmune for funding the later studies. References [1] T. Ding, R. Li, J.A. Zeitler, T. Huber, L.F. Gladden, A.P.J. Middelberg, R.J. Falconer, Optics Express 18 (2010), 27431-27444. [2] T. Ding, T. Huber, A.P.J. Middelberg, R.J. Falconer, J. Phys. Chem. A 115 (2011), 11559-11565. [3] J.W. Bye, S. Meliga, D. Ferachou, G. Cinique, J.A. Zeitler, R.J. Falconer, J. Phys. Chem. B 118 (2014), 83-88.

Fig. 1. The corrected absorbance (αcorr) of BSA in solution versus the number of water molecules around the protein. The solid line is αcorr at 3 THz and dashed line is αcorr at 2 THz.


11

Truth or Fraud – The Role of Vibrational Spectroscopy in Food Authenticity D. COZZOLINO

The University of Adelaide, Waite Campus, Adelaide, 5064, SA, Australia [email protected]

The increasing market and consumer desire for quality food has created a need for efficient and accurate analytical methods for the measurement of chemical composition as well as for the authentication and traceability of foods. Several analytical methods have been or are currently in use to authenticate or trace foods such as UV spectroscopy, High Performance Liquid Chromatography (HPLC), gas chromatography (GC), Liquid Chromatography (LC), and mass spectrometry (MS) among others (Cozzolino, 2012, 2014).

Authentication, traceability, denomination of origin (geographical) or counterfeit of foods and agricultural products is of primary importance to keep consumers demands and to maintain the sustainable nature of the food industry. From a legislative point of view, quality standards were established by the industry and governments in order to set the requirements for quality labels that specify the chemical composition of raw materials and foods. From an economic point of view, product authentication is essential in order to avoid unfair competition that can eventually create a destabilized market and disrupt regional or national economies. These issues in food have two different aspects, one related with authenticity with respect to production (e.g. geographical origin, organic vs. non-organic) and two authenticity with respect to the description (e.g. adulteration issues). For example, geographical and botanical origins of food, such as “natural,” “organic,” “raw,” “unheated”, “fresh vs frozen” has been analyzed using different methods and techniques (e.g. volatile compounds, minerals, carbohydrates, and protein identification) (Cozzolino, 2012).

In recent years, new and challenging risks have emerged as food supply chains have become increasing global and complex (Moore et al., 2012). One of such risks gaining attention from industry, governments, and standards setting organizations is food fraud conducted for economic gain by food producers, manufacturers, processors, distributors, or retailers. Food fraud has been defined as a collective term that encompasses the deliberate substitution, addition, tampering, or misrepresentation of food, food ingredients, or food packaging, as well as the false or misleading statements made about a product for economic gain (Moore et al., 2012).

New approaches such as the use of new algorithms, data pre-processing, the combination of different sensors (sensor fusion) and the developments in hyperspectral spectroscopy proved to be an alternative to the “classical” use of analytical methods in order to improve such approaches. Vibrational spectroscopy techniques such as near (NIR) and mid infrared (MIR) spectroscopy with its intrinsic benefits such as being non-invasive, rapid, and almost no sample preparation, have being able to determine simultaneously physical and chemical parameters in different foods matrices as well as to authenticate and trace different foods (Cozzolino, 2012).

The main advantages of these techniques over traditional chemical and chromatographic methods (e.g. HPLC, GC, GC-MS) are the speed, minimal sample preparation and ease to use in an industrial setting or routine operations. However, adapting and applying this method to efficiently and consistently monitor authenticity, we need to increase our understanding about the chemical and biochemical basis associated with origin/authenticity/traceability derived from the IR spectra, in order to maintain a sustainable food production and to guarantee to the consumers the origin of the foods.

This presentation will provide with an overview of different applications of NIR and MIR spectroscopy to target issues associated with authenticity, discrimination or traceability in several foods, including meat, honey, wine, cereals. Acknowledgement The author wishes to thanks colleagues at INIA La Estanzuela - Uruguay, The Australian Wine Research Institute and The University of Adelaide and the funding bodies Grape and Wine Research Development Corporation and the Grain Research Development Corporation. References [1] D. Cozzolino, App. Spectrosc. Rev. 47 (2012), 518–530. [2] D. Cozzolino, Food Res. Inter. 60 (2014), 262–265. [3] J.C. Moore, J. Spink and M. Lipp, J. Food Sci. 77 (2012), 118–126.


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Spectroscopic Methods in Gemstone Testing L. KIEFERT

Gubelin Gem Lab Ltd., Maihofstrasse 102, Luzern, 6006, Switzerland. [email protected]

Gemmology has long been considered as not being a proper science. Until the 1970's, gemmology was performed by scientists and non-scientists alike only looking at microscopic features, luminescence under UV lamps, specific gravity, refractive index, etc. This was enough to identify the nature of a gemstone and any treatment. Origin determinations were not an issue as long as the gemstone was beautiful. However this changed after the 1970's when with advanced technology gemstone treatments also became more sophisticated. At the same time, new discoveries of gem deposits made it desirable to determine the origin of a gemstone, as some origins are higher regarded than others.

This development made it necessary for gemmological laboratories to explore into new methods of analysis and new instruments. These methods had to be destruction-free. The instruments suitable for such analyses also offered a great possibility to investigate into properties of gemstones that were previously not known. Today, a well-equipped gemmological laboratory uses, besides the above methods, UV-Vis spectroscopy, FTIR spectroscopy, Raman spectroscopy, XRF spectroscopy, as well as LA-ICP mass spectroscopy.1

Some of the applications of the various instruments are listed below: UV-Vis-NIR spectroscopy: Colour is one of the most important characteristics of gems and minerals, and is

generally directly related to certain trace elements, e.g., Ti, Cr, Fe. Certain colours are caused by charge transfer of the electrons such as in sapphire. Sapphire gets its blue colour by the charge transfer between Ti and Fe. UV-Vis-NIR picks up on the state of the element, eg. if a Fe ion is Fe2+ or Fe3+ will be shown in the spectrum. Certain ions are more common in sapphires from different geological settings, and ions can also be changed by certain treatments.2, 3

UV-Vis-NIR spectroscopy is also applied to diamond testing in order to determine a possible treatment. An irradiated diamond shows a peak at 741 nm, which can be removed by annealing. However, the annealing process produces a peak at 594 nm, which again can be removed by excessive heat. However, if the 741 or 594 nm peak is present, one can assume that the diamond has been irradiated.4

FTIR spectroscopy: The best known application of FTIR is the characterization of diamond as they are divided into four major types (Type Ia, Ib, IIa and IIb), based on the amounts and aggregation type of nitrogen traces as well as boron in detectable amounts. Sometimes, the diamond type identification can help to separate natural from synthetic diamonds (Shigley et al., 1995). The presence of peaks at about 4935 and 5165 cm-1 (a.k.a. H1b and H1c respectively) is considered as a positive proof of treatment in diamonds (Collins et al., 1986; Fritsch et al., 1988).5, 6 Rubies from certain sources develop a series of peaks centered around 3309 cm-1when they are heated (Smith, …..).7

Another major application of FTIR spectroscopy is the identification of various types of jade such as jadeite, nephrite, omphacite, and kosmochlor, and their treatments. In the Asian market, jadeite is an important gemstone. The most expensive jadeite comes from Burma, is very dense, and has a transparent to translucent strong green colour. However, the majority of jadeite has a lighter colour and often dark inclusions. Such jadeite is usually bleached to remove the dark inclusions. The bleaching process opens the pores of the gem, which is subsequently filled with a resin or a dye (with or without resin). Resin peaks are readily visible in the FTIR spectrum, so the distinction between a treated and an untreated jadeite is easily made.8, 9

Oil and resin is also used as clarity enhancement in various gemstones, mostly in emerald. FTIR spectroscopy distinguishes between untreated gems, resin treated and oil treated gems. Often this method is used in combination with Raman spectroscopy.10

Raman spectroscopy: Gemmological laboratories started to use Raman spectroscopy in the mid-1990's, when emeralds were not only treated with oil, which was a well established method and already described by Plinii the Elder, but polymer resins came into use. These could not be cleaned out as easily as oil, and therefore caused problems when setting the stone in rings or getting in touch with other chemicals. Therefore the trade needed to know which substance has been used for enhancing the clarity of their emerald. Back then, micro-FTIR was not readily available to gemmological laboratories, so micro-Raman spectrometers allowed the analysis not only of the bulk stone as in FTIR, but concentrate on an individual fissure.10

Since then, the Raman spectrometer has found a wide range of applications, either to identify a gem, an inclusion, or a treatment. The altered state of the zircon lattice shows itself as a difference in FWHM of the various major Raman bands and can help in heat treatment determination. Treatment detection on diamonds (HPHT treatment) and spinel is performed by using the laser of the Raman spectrometer as source for photoluminescence.11, 12

XRF spectroscopy: This is one of the most important methods to determine the major and trace elements of gemstones. The chemical composition of a gem gives information about the nature of the material, distinguishes synthetic from natural materials, reveals certain treatments, and is used for the origin determination of a certain gem by comparing the trace elements.

As an example for treatment identification, inorganic substances such as silver salts and iodine are used to improve the colour of cultured pearls. Such elements can be detected with this instrument.13 Similarly, lead of lead-glass filled diamonds and rubies as well as coatings on gemstones can be detected.14,15

For some gemstones, it is important in the gemstone trade to know their geographic origin. This could either be for ethical reasons ("blood diamonds") or for added value of the gemstone. Certain origins are regarded "higher" as others due to the history behind their deposits. For example, emeralds from Colombia are the ones most highly regarded due to the fact that they have the nicest green, but also because their history goes back to the Spanish Conquerors. Emeralds are mainly coloured by chromium and/or vanadium as well as iron in different concentrations. In general, Colombian


13

emeralds always contain a high amount of V and Cr compared to Fe. The vast majority of the other emeralds contain Cr>>V, most of these found in Brazil, Zambia, Zimbabwe etc. However, there are some other “vanadium rich” emeralds besides Colombia (contain V>Cr); e.g. some Brazilian (Salininha, Bahia), some Chinese (Malipo, Yunnan), and Panjir (Afghanistan) emeralds. The iron concentration is then used for an additional sorting between the “vanadium-rich” emeralds; Colombian emeralds frequently contain very low iron.16,17,18

Laser ablation–inductively coupled plasma–mass spectroscopy (LA-ICP-MS): At the beginning of the 2000's, a large amount of heated orange to orangey-pink sapphires resembling the highly priced so-called padparadscha sapphires entered the gemstone market. These gemstones appeared to be diffusion treated, but none of the advanced methods used in gemmological laboratories at the time showed any differences to the traditionally heated pink to orange corundum. It was only when some further testing using LA-ICP-MS and laser-induced breakdown spectroscopy (LIBS) was performed, that it was noted that the treated samples contained considerable traces of beryllium (Be) compared to the untreated or only heated samples. The beryllium content decreased towards the center of the stone, confirming a diffusion treatment.19

As a consequence, several of the major gemmological laboratories upgraded their instrumentation by acquiring a LA-ICP-MS. Meanwhile, this instrument is mainly used to refine origin determination by taking into consideration trace elements that cannot be detected by XRF. For example, based on the barium concentration and the rare earth element pattern (REE) opals coming from sedimentary environments can be separated from those of volcanic environments.73 Opals from volcanic environments (e.g. from Mexico) present an anomaly to the REE pattern (europium and cerium) and barium concentrations are usually below 110 ppm. On the other hand, opals from sedimentary environments (e.g. from Australia) present no anomaly to the REE pattern and contain barium concentrations above 110 ppm. Taking into account other trace elements, it is sometimes possible to do the geographic origin of opals.20

Spinel is becoming increasingly popular as a gemstone, and consequently there is also demand for origin determination. Recent studies have shown that the elements such as Ti, Fe, V, Cr, Ni, Zn, Zr, Ga and Sn are useful to differentiate gem quality spinels from the Himalayan mountain belt and Eastern Asia, i.e. spinels from Mogok (Myanmar), Luc Yen (Vietnam) and Kuh-i-Lal (Tajikistan). More precisely, spinels from Mogok show the highest Zn, Ti, V, Cr, and Sn concentrations compared to the other two, Luc Yen spinels show the highest Fe content and the lowest Ti and Sn content and Kuh-i-Lal samples show intermediate Zn, Ti, V, Cr, V, Fe and Ga as well as Ni and Zr around the detection limit.21 LA-ICP-MS also helps in the origin determination of corundum, emerald, and alexandrite.

Conclusions: The previous paragraphs showed how gemmology has turned into a science with new requirements in gemstone testing. Nowadays, advanced instrumentation is routinely used on nearly all gemstones. Often the methods are complementary and more than one method is used to determine gemstone treatments and origins. This contribution can only cover a small selection of the applications. More applications, illustrations and extensive references, can be found in1. References [1] L. Kiefert, S. Karampelas, In Analytical Archaeometry; H.G.M.Edwards, P. Vandenabeele (Eds.), Royal Society of Chemistry Publishing (2012), 291-317. [2] H.A. Hänni, J. Gemm., 24 (1994), 139–148. [3] H.P. Kan-Nyunt, S. Karampelas, K.Link, K. Thu, L. Kiefert, P. Hardy, Gems & Gemol., 49 (2013), 223–232. [4] C.D. Clark, A.T. Collins, G.S. Woods, In The Properties of Natural and Synthetic Diamond; J.E. Field (Ed.), Academic Press,

London (1992), 35–79. [5] A.T. Collins, G. Davies, G.S. Woods, J. of Physics C. Solid State Physics (1986), 3933. [6] E. Fritsch, J.E. Shigley, C.M. Stockton, J.I. Koivula, Gems & Gemol., 24 (1988), 165-168. [7] C.P. Smith, J. Gemm., 24 (1995), 321. [8] E. Fritsch, S.-T. Ten Wu, T. Moses, S.F. McClure, M. Moon, Gems & Gemol., 28 (1992), 176-187. [9] L. Kiefert, Gemguide, 31 (2012), 2-7. [10] L. Kiefert, H.A. Hänni, J.-P. Chalain, W. Weber, J. Gemm., 26 (1999), 501-520. [11]J.-P. Chalain, E. Fritsch, H.A. Hänni, J. Gemm., 27 (2000), 73-78. [12] W. Wang, K. Scarratt, J.L. Emmett, C.M. Breeding, t.r. Douthit, Gems & Gemol., 42 (2006), 134-150. [13] S. Elen, Gems & Gemol., 38 (2002), 156-159. [14] J.E. Shigley, S. McClure, Elements, 5 (2009), 175-178. [15] S.F. McClure, C.P. Smith, W. Wang, M. Hall, Gems & Gemol., 42 (2006), 22-34. [16] C.P. Smith, Rapaport Diamond Report, 32 (2009), 139. [17] D. Schwarz, J-C. Mendes, L. Klemm, P-H.S. Lopes, InColor, 16 (2011), 36-46. [18] D. Schwarz, V. Pardieu, InColor, 12 (2009), 2. [19] J.L. Emmett, K. Scarratt, S.F. McClure, T. Moses, T.R. Douthit, R. Hughes, S. Novak, J.E. Shigley, W. Wang, O.

Bordelon, R.E. Kane, Gems Gemol., 39 (2003), 84-135. [20] E. Gaillou, A. Delaunay, B. Rondeau, M. Bouhnik-le-Coz, E. Fritsch, G. Cornen, c. Monnier, Ore Geol. Rev., 34 (2008), 113. [21] A. Malsy, L. Klemm, Chimia, 64 (2010), 741.


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It is an emergency: Spectroscopy outside the laboratory M. LOGAN

Research and Scientific Branch, Queensland Fire and Emergency Services, 24 Corporate Drive., Cannon Hill, 4170, Queensland, Australia [email protected]

An academic laboratory is a secure and clean environment where a variety of vibrational spectroscopic techniques and instruments can be applied to materials identification and analysis. These laboratories often incorporate dedicated expertise to support research and teaching activities. Consider applying those processes and equipment outside that environment where it is not secure, or clean, might be raining, hot, on land, or at sea. This is the situation that confronts emergency responders every day at a hazardous materials emergency. Furthermore, people may be hurt, the incident might be a crime scene, and the identity of the hazardous materials may not be certain. Identifying those hazardous materials is essential. This information is applied to assess how the hazardous materials might affect the safety of emergency responders or that of the surrounding community. The identity of these materials also informs the selection of risk control measures that are applied to safely resolve the incident. The spectroscopic equipment must be suitable to be used in these environments and available 24 hours a day, seven days a week, wherever it is required. Their use must also be supported by robust sampling approaches, as well as ready access to expertise to support their operation and analysis of the spectra obtained.

The Queensland Fire and Emergency Services (QFES) responds to more than 65,000 incidents annually across Queensland. Its response area is about 1.7 million km2. Many incidents involve hazardous materials. They are often mixtures and found in a variety of circumstances, with no obvious identifying features. These circumstances include on surfaces with no obvious container, within containers (both sealed and unsealed), or a spillage adjacent to containers. They may be solids, liquids, and gases. They may be toxic, flammable, corrosive, and exhibit some or all of those intrinsic properties. These incidents may occur on land or at sea. Consequently, the situation may pose considerable challenges and time pressures for emergency responders to safely sample and identify the hazardous materials. The emergency responders often require specialist protective clothing, respiratory protective equipment, detection equipment and operational support structures, such as decontamination and medical support.

The QFES detection and identification capability requires many elements including personnel, equipment, doctrine, and training. Delivery and development of the capability is led by the Research and Scientific Branch. Seven scientists and eight fire-fighters are attached to the Branch and they support about fifty volunteer scientific officers located across Queensland. The Branch also ensure those capabilities are available whenever required.

The QFES has sixteen FTIRs and Raman instruments located across Queensland including gas-phase FTIR and Spatial Offset Raman (SORS) instruments [3]. They include comprehensive spectral libraries and sampling accessories developed by the Branch. The instruments available and used within the QFES include: MIDAC Titan FTIR; Smiths FTIR; Perkin Elmer FTIR; Ahura Raman; and Cobaltlight SORS Raman.

The possession of spectroscopic instruments is a start, but there remain many challenges to ensure they can be operationally deployed outside a laboratory environment. Most samples within academic based laboratories include few other components and usually do not pose an unacceptable risk to the spectroscopists safety or life. Firstly, consider the classical approach to sample presentation using mulls or salt based discs using transmission FTIR and its suitability outside the laboratory. In the past 15 years, a variety of Attenuated Total Reflectance (ATR) based FTIR instruments have become commercially available [1] for use in challenging operational environments. They have found wide application at hazardous materials incidents, including identifying “white powders”, illicit drugs and other materials.

Miniaturised and portable Raman spectrometers have also become widely commercially available [1,2,4]. They have found application for the identification of illicit drugs and energetic materials, commonly known as home-made explosives. These energetic materials are often particularly sensitive to accidental initiation, especially if they are impure.

These field portable FTIR and Raman instruments often combine proprietary spectral libraries with chemometric techniques to identify the spectrum and its components. Many users rely solely on the outcome of a search. However, expertise is still required to understand sample presentation and interpretation of the spectrum.

The QFES has invested much effort to adapt classical laboratory sampling techniques (solid, liquid and gas) and develop new techniques to demonstrate their utility in field operations with both FTIR and Raman instruments. The QFES has also extended the application of these instruments at emergency situations. The operational environments have ranged from maritime (on a ship) to land and operators requiring the use of personal protective equipment, such as a vapour tight protective ensemble.

The presentation will illustrate the operational challenges confronting the QFES and other emergency response organisations applying traditional laboratory based vibrational spectroscopy. These needs and challenges will be contrasted with those occurring in a laboratory based environment.

The presentation will also highlight approaches that have been successfully used to sample hazardous materials and identify them at a variety of emergency incidents. In some cases the materials of interest were synthesised, and then the sampling and identification approaches tested to determine their suitability for successful application at emergency incidents. An example is the FTIR spectrum of triacetone triperoxide (TATP) obtained from a subsample that was prepared as a thin-film of quantity found at a residence. The QFES has also demonstrated, for the first time the gas-phase FTIR spectrum of the same material obtained without any need to directly handle the sensitive material.


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Further examples highlighting approaches using Raman instruments will be discussed including, applying the novel SORS instruments to operational environments. These include identification of a “dark” energetic material and materials within sealed containers. References [1] D.Sorak, L.Herberholz, S.Iwascek, S.Altinpinar, F.Pfeifer, H.Siesler, Applied Spectroscopy Reviews. 47, (2012) 83-115 [2] K.Carron, R.Cox, Analytical Chemistry. 82, (2010), 3419-3425. [3] P.Matousek, I.Clark, E.Draper, M.Morris, A.Goodship, N.Everall, M.Towrie, W.Finney, A.Parker, Applied Spectroscopy. 59,

(2005), 393-400. [4] E.Izake, Forensic Science International. 202, (2010), 1-8.


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Hard Truths about Soft Matter: From Single Polymer Chains to Single Swarming Bacteria E. K. L. YEOW

Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore [email protected]

Many important insights into materials science and biomedical science can be gained by examining the motion of individual entities in real time. In this presentation, I will discuss how time-lapse microscopy is used to understand ubiquitous phenomena such as polymer crystallization,1 phase separation in binary polymeric systems,2 coffee ring formation,3 and soft matter phase transition. In addition, this technique is also used to examine drug interactions occurring in swarming bacteria.4 References [1] Bi, W.; Teguh, J.S.; Yeow, E.K.L., Phys. Rev. Lett. 2009, 102, 048302. [2] Bi, W.; Yeow, E.K.L., Phys. Rev. Lett. 2011, 106, 078001. [3] Bi, W.; Wu, X.; Yeow, E.K.L., Langmuir 2012, 28, 11056-11063. [4] Lu, S.; Bi, W.; Liu, F.; Wu, X.; Xing, B.; Yeow, E.K.L., Phys. Rev. Lett. 2013, 111, 208101.


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Low-concentration Analyte Quantification in the Solid State Using Raman Spectroscopy and Chemometrics A. G. RYDER1*, B. LI1, A. CALVET1, C. MORRIS1, AND Y. CASAMAYOU-BOUCAU1 1Nanoscale Biophotonics Laboratory, School of Chemistry, National University of Ireland-Galway, Galway, Ireland. Email: [email protected]

Many solid-state materials such as active pharmaceutical ingredients (APIs) contain impurities that are typically present at concentrations of <0.5% w/w. These impurities need to be identified and quantified, and high performance liquid chromatography (HPLC) is typically the method of choice in pharmaceutical applications. Unfortunately, HPLC is not capable of analysing for some solid-state contaminants such as polymorphs and some solvates. Raman spectroscopy on the other hand is very well suited to the identification and quantification of most impurities including polymorphs and solvates. However, in the solid-state, the application of Raman spectroscopy for routine analyte quantification below ~0.5% w/w is not routine.

Raman imaging (or more correctly, in this context, high-number, point-sampling, HNPS) has been used for low level (0.025 to 0.1% w/w) impurity detection in tablets [1]. To extend this to achieve robust and accurate, low content (<0.1% w/w) quantification, we have been investigating the use of the signal heterogeneity contained in Raman imaging data. Pixel-to-pixel Raman signal variation is caused by local fluctuations in sample consistency, and this sample heterogeneity can be correlated with, for example, the concentration of impurities in the bulk sample. To extract the relevant composition information to make these correlations we have to combine HNPS, with standard chemometric methods and statistical analyses to provide robust and accurate quantification in the 0.01 to 0.1% w/w concentration range.

The first model system we studied comprised of solid mixtures of piracetam and proline (61 samples prepared in triplicate), which was selected because both components have nearly equal Raman scattering co-efficiencies. For each sample, ~8400 Raman spectra were collected from a 29×29 pixel map using a PhAT Imaging workstation (Kaiser). The quantification method involved first building several discrete piracetam concentration models using partial least-squares (PLS) regression [3]. These PLS models were then used to predict the local concentration of piracetam at each pixel. The combined local concentration predictions were finally statistically analysed to generate the true sample concentration. The piracetam contaminant concentration was quantified with a relative accuracy of ~2.4% over the 0.05−1.0% w/w concentration range [2] and the limit of detection was 0.03% (comparable with HPLC). For this approach to be feasible in an industrial setting, all steps in the data analysis had to be automatable including baseline and cosmic ray artefact correction [4], and informative variable selection. A similar HNPS approach is now also being applied to more complex four component powders and tablets, with a goal of quantifying API concentrations in the 0.001 to 0.1% w/w range. Acknowledgement: This work was undertaken as part of the Synthesis and Solid State Pharmaceutical Centre funded by Science Foundation Ireland and industry partners, and Enterprise Ireland (Grant No: TC-2012-5106). We thank Kaiser Optical Systems, Inc. and Mr. H. Owen for the loan of the Raman instrumentation. References: [1] S. Šašić, S. Mehrens, Anal. Chem., 84, 1019 (2012). [2] B. Li, A. Calvet, Y. Casamayou-Boucau, C. Morris, and A.G. Ryder, Anal.l Chem., 87(6), 3419 (2015). [3] S. Wold, M. Sjostrom, L. Eriksson, Chemom. Intell. Lab. Syst., 58, 109 (2001). [4] B. Li, A. Calvet, Y. Casamayou-Boucau, A.G. Ryder, in preparation.


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Shedding light on indigenous art: using vibrational spectroscopy to understand Australasian paint chemistry B. H. STUART1*, P. S. THOMAS1, A. HUNT1 AND L. CHUA1 1University of Technology Sydney, 15 Broadway, Ultimo, 2007, NSW, Australia e-mail. [email protected]

The use of infrared and Raman spectroscopies for questions in art conservation and archaeology has expanded in recent years with technological developments in the field. In particular, the availability of improved micro-spectroscopic sampling methods has allowed precious minute cultural heritage specimens to be examined without damaging artefacts, while being able to take advantage of improved resolution. The results of spectroscopic projects underway at the University of Technology Sydney involving indigenous artworks from Australia and Papua New Guinea will be presented. Projects include the analysis of Arhnem Land rock art and artefacts from the Highlands of Papua New Guinea.

In 2007 spectacular remote rock art sites located in Jawoyn country on the Arnhem Land plateau located in northern Australia were rediscovered. The art at these sites is made up of paintings of different ages with an array of materials and styles associated with the different generations employed. A current project in collaboration with Monash University, the University of Bordeaux and the University of Savoie in France involves the characterisation of the paints used at one of the sites, an enclosed rock shelter known as Dalakngalarr 1. Obtaining a clear understanding of the age and material types at such important archaeological sites is a challenge as the remote location makes in situ analysis difficult. However, permission was kindly provided by the traditional owners to remove minute specimens of paint from the site in order to carry out chemical analysis. One of the techniques being employed is infrared spectroscopy to gain insight into the chemical composition of specimens of different colour and generations from the Dalakngalarr 1 site. Some examples of the identification of the mineral content and possible alteration products of the pigments found at the site will be described

The Art Gallery of New South Wales (AGNSW) holds a significant collection of painted ceremonial objects from the Highlands of Papua New Guinea (PNG). In order to appropriately care for such objects, it is necessary to determine the nature of the paint applied to the objects. A detailed characterisation of the paint chemistry will also provide an understanding of the source of the variety of pigments employed during different periods in the Highland region of PNG. FTIR and Raman spectroscopy have been used to determine the composition of paint fragments collected from a variety of artefacts, including shields, hats and wigs, from the AGNSW that were collected during the mid-20th century.


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FTIR Hyperspectral Imaging for Rapid Identification of Pathogenic Microorganisms P. LASCH1*, M. STÄMMLER1, M. ZHANG1 AND K. MAJZNER2

1Robert Koch-Institute, ZBS6 - Proteomics and Spectroscopy, Seestraße 10, Berlin, D-13353, Germany, [email protected] 2Jagiellonian University, Faculty of Chemistry, 3 Ingardena, 30-060 Krakow, Poland

The past decade has witnessed substantial progress towards the application of infrared (IR) microspectroscopic imaging as a useful diagnostic tool for characterization of microbial, cytological and histological specimens. In this presentation the application of mid-IR hyperspectral imaging for rapid, objective and cost effective diagnosis of pathogenic microorganisms will be illustrated

The proposed method involves a relatively short cultivation step of microorganisms under standardized conditions, transfer of the material onto suitable IR windows by a replica method, IR hyperspectral imaging measurements and image segmentation analysis by means of artificial neural networks (ANNs).

For this purpose, aliquots of the initial microbial cell suspension are sufficiently diluted to guarantee single colony growth on solid agar plates. After an incubation period of 6-8 hours microbial microcolonies have typically diameters between 30 and 150 µm. Microcolony imprints can be subsequently produced by using a specifically developed stamping device. The stamping technique allows spatially accurate transfer of the microcolonies’ upper cell layers onto IR windows, usually CaF2, glued in specific Teflon® holders. The stamping device is equipped with a plastic hose that prevents twisting or lateral displacement during stamping. Using this device, stamping is carried out by gently lowering the holder onto the agar plates. After stamping, the microcolony imprints are allowed to dry and are then transferred to the IR imaging device. Dried sample spots are measured operator-controlled by means of video techniques for specifying regions of interest and for documentation purposes. FTIR hyperspectral imaging measurements are carried out by employing an Agilent Cary 620 focal plane array (FPA) micro-spectroscopic imaging system (Agilent Technologies, Santa Clara, USA) which is equipped with a 128×128 multi-element MCT (HgCdTe) FPA detector. The pixel size of each single detector element is about 5.5×5.5 µm2 giving an effective lateral spatial resolution of approximately 12 µm at 1000 cm-1. Spectral data analysis involved application of supervised ANN models. These models are required to be trained and validated in an initial teaching phase by means of labelled subsets of teaching spectra. In the test phase false-color ANN segmentation images are obtained by converting the ANN output functions to color values and combining them with the available spatial information: ANN imaging involves plotting of colored pixels at the spatial coordinates at which the individual pixel spectra were measured. The resulting segmentation maps thus encode the spatial distribution of taxon-specific spectral patterns.

An example of how the IR micro-spectroscopic imaging technique can be used in combination with the ANN image segmentation method is given in Figure 1. The left column of this figure shows microphotographs of stamping imprints obtained from a mixed culture of Escherichia coli, Bacillus subtilis and Staphylococcus aureus. The right column of Figure 1 illustrates the results of ANN image segmentation. Dark grey colored regions (3) illustrate the presence of spectra with the typical features of S. aureus, while grey areas (1) encode regions where spectra of E. coli are found. Black colored pixels denote regions with unclassifiable spectra. Currently we are systematically examining much larger spectral data sets to prove the hypothesis that spectra obtained from microbial microcolonies can be used to differentiate, classify and identify very small amounts of microorganisms at the genus, species and at the strain level.

References [1] P. Lasch, D. Naumann, Infrared Spectroscopy in Microbiology, Encyclopaedia of Analytical Chemistry (2015), 1–32.

Fig. 1. Characterization of microcolony imprints using mid-IR microspectroscopic imaging data collected by means of a 128×128 FPA FTIR imaging system, chemical imaging and a segmentation approach based on artificial neural network (ANN) analysis..


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Molecular Reaction Dynamics in Condensed Phase by Extreme Time-Resolved Fluorescence T. JOO

Department of Chemistry, POSTECH, 77 Cheongam-Ro, Pohang, 790-784, Korea, [email protected]

Elementary time scale of the nuclear motions in molecules corresponds to the periods of molecular vibrations, which are in the range of 10−100 fs. Femtosecond spectroscopy is therefore an ideal tool to study a variety of nuclear dynamics in molecules including chemical reactions. Although pump/probe transient absorption is the standard technique of femtosecond spectroscopy, time-resolved spontaneous fluorescence (TRF) provides intuitive, accurate, and direct information on the dynamics at the expense of lower time resolution. By the advances made in our laboratory for the high time resolution, sensitivity, and TRF spectra acquisition without the spectral reconstruction, we can now routinely achieve 30 fs time resolution in TRF, which allows direct observation of the vibrational wave packet motions in the excited state. We use ultrahigh time-resolved fluorescence to investigate the dynamics of electronic excited states in liquids including solvation dynamics, vibrational wave packet motions, vibronic relaxation, internal inversion, excite state intramolecular proton transfer (ESIPT), and excited state intramolecular charge transfer reactions.

When a molecule is excited impulsively by a short pulse of light, that is, the pulse duration is shorter than half of the vibrational periods, coherent vibrational wave packets can be created. The wave packet motions thus created are manifested in the oscillations of the time-resolved absorption and emission spectra in frequency as well as in intensity. For the Franck-Condon transition, the amplitude of a coherent vibrational wave packet in the impulsive excitation is proportional to the projection of the displacement between the ground and excited states onto the normal mode in the excited state, which is the well-known Huang-Rhys factor. The same procedure can be extended to the case of ultrafast intramolecular chemical reactions, where the displacement vector is now between the reactant and product. The vibrational modes coherently excited in the product and their decay provide a wealth of information on the dynamics and molecular structures of the states involved.

I will present some of our recent developments on the ultrafast processes in molecules. (1) Ultrafast intramolecular charge transfer (ICT) dynamics of 4-(dimethylamino)benzonitrile (DMABN) and related compounds [1-2]. The ICT of DMABN proceeds in several time scales ranging from <30 fs, ~100 fs, and a few picosecond. The initially excited S2 state undergoes rapid transition to both LE and ICT state through a conical intersection. The LE state undergoes LE-ICT conversion in 100-200 fs time scale and a few picosecond time scale, followed by the intramolecular solvation on the ICT state involving mainly the rotation of the dimethylamino group. (2) ESIPT of 2-(2′-hydroxyphenyl)benzothiazole (HBT), 10-hydroxybenzo[h]quinoline (HBQ) and related molecules [3-4]. Here we found that the rate of ESIPT depends strongly on the distance between the proton and the proton acceptor (usually nitrogen) through the hydrogen bond. I will also discuss on the role of proton in the ESIPT, active or passive. (3) Coherent internal conversion processes in molecules. We have found many examples of the coherent internal conversion processes in large molecules such as porphyrins and rhodamines. By the observation of the coherent wave packet motion in the final S1 state, the nuclear coordinates that couples strongly with the internal conversion could be identified. Acknowledgement I thank all the former and current members of the Ultrafast Dynamics Laboratory at POSTECH. References [1] M. Park, C.H. Kim, T. Joo, J. Phys. Chem. A 117 (2013), 370. [2] M. Park, D. Im, Y.H. Rhee, T. Joo, J. Phys. Chem. A 118 (2014), 5125. [3] S.N. Lee, J. Park, M. Lim, T. Joo, Phys. Chem. Chem. Phys. 16 (2014), 9394. [4] J. Lee, C.H. Kim, T. Joo, J. Phys. Chem. A 117 (2013), 1400.

ACOVS11/ASC5 Book of Abstracts Session I - Synchrotron

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SESSION I – SYNCHROTRON


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Optical Constants of Aerosols from Synchrotron Infrared Spectroscopy M. RUZI1*, C. P. ENNIS1, 2, D. R. T. APPADOO2, AND E. G. ROBERTSON1

1Department of Chemistry and Physics, Latrobe Institute for Molecular Sciences, Latrobe University, Melbourne, 3086, Victoria, Australia [email protected] 2Australian Synchrotron, Blackburn Rd., Clayton, 3168, Victoria, Australia

Aerosols are important constituents of the atmosphere. They affect the radiation budget and hydrological cycle of earth. Depending on the composition and size, aerosols have either net warming or cooling effect. Aerosols also have been observed in the interstellar medium, and in the atmosphere of other planets such as Titan, a moon of Saturn.1 Aerosol size and complex refractive indices are two important parameters from the perspective of understanding radiation budget and remote detection. These parameters dictate the amount of light that aerosols absorb/scatter and the pattern of such interactions. The absorption/scattering of light by aerosols is responsible for some everyday phenomena, such as low visibility smog in cities and the blue haze in Blue Mountains.2

Complex refractive indices of aerosols are needed for understanding radiation budget and interpreting spectral data whether it is of earth’s atmosphere or of extraterrestrial environments. Refractive indices for the material of interest can be retrieved from conventional spectroscopic techniques, such as FTIR. Traditionally, such measurements are conducted on thin films deposited on substrates where interference effects at interfaces can cause distortion and baseline shifts in spectra. Although it is called ‘thin film’, in practice the films are not ‘thin’ enough compared to the IR wavelength. The refractive indices extracted from such thin film spectra can be quite different from those obtained from aerosols which are usually suspended in a buffer gas, similar to atmospheric aerosols.

In this study, we present various methods to retrieve the complex refractive indices of aerosols from FTIR spectra and discuss the ease of application and accuracy for each method. Small aerosols (<100 nm) attenuate the IR beam mainly by absorption which can be easily simulated by Rayleigh scattering, whereas scattering is dominant for larger particles (> a few micron) where more rigorous Mie scattering theory is needed.3 The analysis and discussions are corroborated using aerosol FTIR spectra taken at the Australian Synchrotron over the years. These aerosols are of atmospheric or astrophysical importance, which include water ice (H2O), carbon dioxide (CO2), formic acid (HCOOH), acetonitrile (CH3CN), propionitrile (CH3CH2CN), and ethane (C2H6). Acknowledgement We acknowledge the assistance of staff of the THz/Far-IR Beamline at the Australian Synchrotron, and the facility for providing access. M. Ruzi acknowledges the Latrobe University LTUPRS scholarship. References [1] K. Rages, J. B. Pollack, P. H. Smith, J. Geophys. Res. 88 (1983), 8721-8728. [2] F. W. Went, Nature 87 (1960), 641-643 [3] C. F. Bohren and D. R. Huffman, Absorption and scattering of light by small particles, John Wiley & Sons, New York, 1983


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Synchrotron studies of Titan’s cyanide haze. R. AUCHETTL1*, C. ENNIS1, M. RUZI1 AND E. G. ROBERTSON1

1Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, Victoria, Australia

In 2004, the NASA/ESA [1,2] Cassini-Huygens space mission allowed our first orbiting rendezvous with Saturn’s largest moon Titan; unveiling its chemically diverse atmosphere and shrouded, icy surface [3]. To date, Titan is observed to be the only other planetary body with a level of molecular complexity comparable to that of Earth [4]. For example, gas-phase reactions appear to proceed within the dense Titan atmosphere driven by photolytic and radiolytic processes which leads researchers (see [5] and references therein), to question if there is a link between the stellar organic chemistry of Titan and the chemical pathways that seeded life on our planet. As the Cassini probe continues to explore Saturn’s chemical environment, there has been an effort amongst astrochemists to research the reactivity of the observed species under simulated planetary conditions using theoretical modelling and laboratory experiments; with the findings likely to give new insight towards prebiotic chemistry on Earth [6].

The NASA Voyager space probes in the 1980s showed that Titan’s atmosphere was comprised mainly of N2 and CH4 [7]. Here, ongoing photolytic and radiolytic interactions with these precursor molecules yield a suite of nitrile (CN family) species such as hydrogen cyanide (HCN), acetonitrile (CH3CN) and ethyl cyanide (CH3CH2CN). Further processing is also proposed to generate the polymeric species (tholins) that are observed to condense at specific altitudes; ultimately forming suspended aerosol species which contribute to the distinctive orange haze layer associated with the Titan atmosphere. These species are also observed to appear and disappear with the Titan seasons, as seen via suspected aerosol far-infrared (far-IR) absorption bands at 220 cm-1 [9]. However, to complicate assigning these features, there have been no previous mid-IR and far-IR spectroscopic analyses on the morphology and optical constants of nitrile aerosols - such as HCN, CH3CN and CH3CH2CN - under astrochemical conditions comparable to Titan. Researchers have also not yet determined the importance of temperature, pressure and particle size on the morphology and spectra of pure nitrile aerosols (CH3CN and HCN) over IR wavelengths. Yet without such an understanding, the fundamental morphology of the nitrile aerosols will remain unresolved and the unidentified emission features observed in the stratosphere of Titan cannot be identified.

In this talk we present preliminary results from mid-infrared and far-infrared studies of select nitrile aerosols under conditions replicating that of the Titan atmosphere. The laboratory study was completed at the Australian Synchrotron Terahertz/Far-Infrared beamline using a specialised enclosive flow cooling (EFC) cell to generate populations of nitrile aerosol. This work builds upon previous methodologies with pure water aerosol investigations [13–16]. Our research will provide the astrochemistry community complete infrared signatures of pure nitrile aerosols in the mid-infrared and far-infrared regions over a wide range of astrochemical conditions. This work will shed light on the temperature, pressure and particle size dependence on the morphology and spectra of nitrile aerosols in the mid and far-infrared. Acknowledgement This research was undertaken on the THz/Far-Infrared beamline at the Australian Synchrotron, Victoria, Australia. R.A is a recipient of a La Trobe University Postgraduate Research Scholarship (LTUPRS). MR is a recipient of a La Trobe University Postgraduate Research Scholarship (LTUPRS). References [1] ESA (2015) . [Online]. Available: http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens. [Accessed: 06-Jul-2015] [2] NASA (2015) . [Online]. Available: http://saturn.jpl.nasa.gov/. [Accessed: 06-Jul-2015] [3] Niemann, H.B. et al. (2005) Nature. Nature 438, 779–84 [4] Raulin, F. (2007) Orig. Life Evol. Biosph. 37, 345–9 [5] Ali, A. et al. (2015) Planet. Space Sci. 109–110, 46–63 [6] Raulin, F. et al. (2012) Chem. Soc. Rev. 41, 5380–93 [7] Hanel, R. et al. (1981) Science 212, 192–200 [8] Israël, G. et al. (2005) Nature. Nature 438, 796–9 [9] Jennings, D.E. et al. (2012) Astrophys. J. 754, L3 [10] Li, Q. (2003) J. Geophys. Res. 108, 8827 [11] Kleinböhl, A. et al. (2006) Geophys. Res. Lett. 33, L11806 [12] Becker, K.H. and Ionescu, A. (1982) Geophys. Res. Lett. 9, 1349–1351 [13] Medcraft, C. et al. (2013) Phys. Chem. Chem. Phys. DOI: 10.1039/c3cp43974g [14] Medcraft, C. et al. (2012) Astrophys. J. 758, 17 [15] McNaughton, D. et al. (2010) Anal. Chem. 82, 7958–7964 [16] 1Robertson, E.G. et al. (2009) Phys. Chem. Chem. Phys. 11, 7853–60


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Single Contact ATR Mapping of Soft Materials by Synchrotron FTIR M.J. TOBIN1*, K.R. BAMBERY1, J. VONGSVIVUT1, D.E. MARTIN1, L. PUSKAR2, D.A. BEATTIE3, E.P. IVANOVA4, S.H. NGUYEN4, H.K. WEBB4

1Australian Synchrotron, 800 Blackburn Road, Clayton, VIC 3168, Australia 2BESSY II Synchrotron, Helmholtz-Zentrum Berlin, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany 3Ian Wark Reserch Institute, University of South Australia, Mawson Lakes, Adelaide, SA 5095, Australia 4Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, Australia

Attenuated Total Reflection (ATR) is a sampling method frequently used for FTIR microanalysis of samples which

cannot be prepared as thin sections for transmission analysis [1]. Generally, an ATR prism is attached to the front of the microscope objective and 2D mapping achieved by repeated contacts with the ATR crystal. The method is more suited to harder materials, since the multiple ATR contacts may lead to damage of softer materials. We have developed ATR devices for the purpose of analysing softer materials, where only gentle contact can be made with the sample surface, in which the ATR crystal is attached to the microscope stage rather than the objective. Figure 1A shows our latest ATR device which is similar in principle to the “Macro” ATR devices offered by some manufacturers, but employs more precise piezoelectric sample alignment and ATR contact control. A modified micro-compression cell in which a ZnSe ATR prism is brought gradually into contact with the surface of the sample has also been used to study the hydration water in chitosan-hyaluronic acid model biolubricant, as a function of pressure [2]. Figure 1B shows the OH spectral shift between bulk water (plot 3) and less strongly hydrogen bonded hydration water within the film (plot 2).

As part of a study of the resistance of insect wings to biofilm formation, the same ZnSe ATR has been used to map the surface of structured fatty acid films. Figure 1C shows a map of the relative peak position of νCH2 absorption of a textured stearic acid film on graphite, being studied as an analogue to the dragonfly wing epicuticle.

Fig 1: A. Piezo controlled sample mount with ATR crystal attached to stage, B. OH absorption in chitosan-hyaluronic acid model biolubricant, C. νCH2 relative peak position of a textured stearic acid film.

As with conventional mapping ATR microspectroscopy, the sampling area which is probed by the IR beam is reduced in size by the refractive index of the ATR material; 2.4x for ZnSe and 4x for germanium. However, unlike conventional mapping ATR, the use of an ATR prism which remains in contact with the sample also reduces the step size of beam translation across the sample each time the microscope stage is moved. This step size reduction also scales with the refractive index of the ATR material, further enhancing the potential of the technique to resolve features within the sample. This custom ATR device is anticipated to have ongoing applications in the IR microanalysis of softer materials, including biological tissues, polymers and food products. References [1] W. van Bronswijk and R. Pidgeon, Vibrational Spectrosopy 75, 149-153 [2014]. [2] D.A. Beattie et al., Langmuir 28, 1683-1688 [2012].


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Vibrational spectroscopic studies of photoactivatable diazido Pt(IV) anticancer complexes R. R. VERNOOIJ1*, T. JOSHI1, B. R. WOOD1,2, D. APPADOO3, E. I. IZGORODINA1, B. GRAHAM4, P. J. SADLER5 AND L. SPICCIA1 1School of Chemistry, Monash University, Wellington Road, 3800 VIC, Australia, [email protected] 2Centre for Biospectroscopy, Monash University, Wellington Road, 3800 VIC, Australia 3Australian Synchrotron, 800 Blackburn Road, 3168 VIC, Australia 4 Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, 3052 VIC, Australia 5Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK

Photoactivated anticancer Pt(IV) pro-drugs have the potential to overcome the side-effects encountered with the current clinically-approved Pt-based chemotherapeutics such as cisplatin, carboplatin and oxaliplatin, and Pt resistance on account of their novel mechanism of action. Pt(IV) diazido complexes are promising candidates [1,2], for example trans,trans,trans-[Pt(N3)2(OH)2(pyridine)2] (C1, Figure 1), which exhibits potent activity towards a range of cancer cells upon irradiation with UV-A and visible light. Detailed studies to elucidate the mechanism of action of C1 suggest that Pt(II), nitrene and radical photoproducts, as well as cleaved ligands, act in concert to elicit the observed multi-targeted biological activity [2,3]. In this work, we use state-of-the-art vibrational spectroscopic techniques to gain insight into the mechanism of action of such photoactivated Pt(IV) compounds. More specifically the nature of the photo-adducts with nucleic acids as well as cellular and biomolecular interactions of the Pt(IV) pro-drugs upon irradiation. Spectroscopic techniques used to study these interactions include Infrared and Raman spectroscopy, Synchrotron Far-Infrared spectroscopy and Synchrotron Infrared Microspectroscopy. These techniques offer excellent non-destructive and label-free methods for the analysis of biological specimens [4]. Density Functional Theory calculations have been carried out in concert to complement the spectroscopic analysis. References [1] N.J. Farrer, J.A. Woods, L. Salassa, Y. Zhao, K.S. Robinson, G. Clarkson, F.S. Mackay, P.J. Sadler, Angew. Chem. Int. Ed., 2010, 49, 8905-8908. [2] Y. Zhao, J.A. Woods, N.J. Farrer, K.S. Robinson, J. Pracharova, J. Kasparkova, O. Novakova, H. Li, L. Salassa, A.M. Pizarro, G.J. Clarkson, L. Song, V. Brabec, P.J. Sadler, Chem. Eur. J., 2013, 19, 9578-9591. [3] H.-C. Tai, R. Brodbeck, J. Kasparkova, N.J. Farrer, V. Brabec, P.J. Sadler, R.J. Deeth, Inorg. Chem., 2012, 51, 6830-6841. [4] M.J. Baker, J. Trevisan, P. Bassan, R. Bhargava, H.J. Butler, K.M. Dorling, P.R. Fielden, S.W. Fogarty, N.J. Fullwood, K.A. Heys, C. Hughes, P. Lasch, P.L. Martin-Hirsch, B. Obinaju, G.D. Sockalingum, J. Sulé-Suso, R.J. Strong, M.J. Walsh, B.R. Wood, P. Gardner, F.L. Martin, Nat. Protocols, 2014, 9, 1771-1791.

Fig. 1. Schematic illustration of cellular and biomolecular interactions of trans,trans,trans-[Pt(N3)2(OH)2(pyridine)2] (C1) studied by vibrational spectroscopy.


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Mechanism of water oxidation by Photosystem II: water exchange kinetics, FTIR and isotope effects. A presentation in memory of Warwick Hillier M. CHEAH

Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Canberra ACT 2601, Australia

Water oxidation by Photosystem II (PSII) is one of the most important reaction in the biosphere. In this reaction water is oxidised by a Mn4CaO5 cluster within PSII: 2H2O à O2 + 4H+ + 4e-. This reaction is the source of electrons that drives all subsequent reactions in the photosynthetic chain and is ultimately responsible for sustaining most lifeforms on Earth. Elucidating the reaction mechanism of water oxidation by PSII remains a holy grail in photosynthesis research and in development of artificial water oxidation catalysts. This presentation will summarise the works of the late Warwick Hillier (1967-2014) in examining the reaction mechanism of PSII with particular emphasis on substrate water exchange kinetics of the Mn4CaO5 cluster within PSII. Recent work on isotope effects of water oxidation by PSII shall be presented as well.

ACOVS11/ASC5 Book of Abstracts Session II - Plasmonics

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SESSION II – PLASMONICS


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Nanoscale optical properties visualized by tip-enhanced Raman & THz Raman spectroscopy N. HAYAZAWA1,2,3 1Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan, [email protected] 2Innovative Photon Manipulation Research Team, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan 3Department of Electronic Chemistry, Tokyo Institute of Technology, Nagatsuta, Kanagawa 226-8502, Japan

Since its inception in the year 2000 [1-3], tip-enhanced Raman spectroscopy (TERS) has been recognized as one of the promising spectroscopic techniques in nanoscale due to the plasmonic properties of tip-enhancement, which work for both photon confinement and enhancement. From the scientific point of view, lots of efforts have been paid for the improvement of spatial resolution and sensitivity. One of the promising approaches is utilizing nonlinear response of material such as the narrowband coherent anti-Stokes Raman scattering (CARS) [4] and broadband CARS [5,6]. The other approach recently on trend is the hot spot engineering of gap-mode plasmon based on scanning tunnelling microscopy (STM) based TERS, which achieved up to ~1 nm spatial resolution both in UHV [7] and in ambient [8]. Indeed it is of essential importance to seek for the extreme spatial resolution as TERS has been constituted and ordained to be the ultimate sensing technique in the nanoscale based on photonics, whereas it is equally important to polish the technique to be matured as an analytical tool for everyone. Recently several companies are trying to commercialize TERS as a combination of scanning probe microscopy (SPM) and micro Raman spectroscopy. However, one of the perennial issues in TERS is its tip-enhancement effect reproducibility. In this talk, I will put a disclosure to this issue by affirming that at least highly reproducible (up to almost 100%) tips with a sufficiently high enhancement are now within our reach based on commercially available silicon cantilever tips [9]. In order to utilize the potential of the tips, the position stability of the tip relative to the light field is of crucial importance. I will introduce the robust yet simple method to stabilize the system [10], which is an add-on of the conventional optical microscope and is useful for any position/surface sensitive spectroscopic techniques, e.g. second harmonic generation.

In addition to the reproducibility and stability issue of TERS, another important parameter as an analytical tool is the temperature of the tip-enhanced field, which strongly affects the physicochemical properties of the material, in particular, thermally sensitive materials, e.g. proteins, DNA. The local temperature of the tip-enhanced field can be easily increased depending on the plasmonic system of the metallic tip and or the substrate, as it was predicted analytically [11]. Even though, the affirmation into this point has been experimentally unclear yet. The second half of my talk deals about the local temperature determination in TERS both in high temperature range (>100ºC) [12] and low temperature range (<100ºC) [13]. At the high temperature range, the tip temperature is determined by the temperature dependent Raman scattering of Silicon [14] since the tips are made by coating metal onto a silicon cantilever tip. The high temperature at the tip apex is utilized for TERS at an elevated temperature [12]. The same goes for nano-fabrication [15]. However, the proposed technique is not sensitive to low temperature range (<100ºC) and the extracted temperature is not exactly the temperature of the probed volume but that of the tip. For the low temperature range, the local temperature of a nanoscale volume is precisely determined by tip-enhanced terahertz Raman spectroscopy in the range of several tens of degrees [13]. The heat generated by the tip-enhanced electric field is directly transferred to the sample (single walled carbon nanotubes in this talk) by conduction and radiation at the nanoscale. This way of heating modulates the intensity ratio of anti-Stokes/Stokes Raman scattering of the radial breathing mode of the carbon nanotube based on the Boltzmann distribution at elevated temperatures. Attributable to the low energy feature of the radial breathing mode, the local temperature of the probing volume has been successfully extracted with high sensitivity. The dependence of the temperature rise underneath the tip apex on the incident power coincides with the analytical results calculated by a finite element method based on the tip-enhancement effect and the consequent steady state temperature via Joule heat generation. The results show that local temperature at the nanoscale can be controlled in the low temperature range simply by the incident laser power while exhibiting a sufficiently high tip-enhancement effect as an analytical tool for thermally sensitive materials.

Acknowledgement N.H. gratefully acknowledge the financial support by the ‘Grant-in-Aid for Scientific Research (B)’ No. 15H03569 from the Ministry of Education, Culture, Sports, Science and Technology of Japan. References [1] N. Hayazawa, Y. Inouye, Z. Sekkat, S. Kawata, Opt. Commun. 183 (2000), 333–336. [2] R. M. Stockle, Y. D. Suh, V. Deckert, R. Zenobi, Chem. Phys. Lett. 318 (2000), 131-136. [3] M. S. Anderson, Appl. Phys. Lett. 76 (2000), 3130-3132. [4] T. Ichimura, N. Hayazawa, M. Hashimoto, Y. Inouye, S. Kawata, Phys. Rev. Lett. 92 (2004), 220801. [5] K. Furusawa, N. Hayazawa, S. Kawata, J. Raman Spectrosc. 41 (2010), 840-847. [6] K. Furusawa, N. Hayazawa, F. C. Catalan, T. Okamoto, S. Kawata, J. Raman Spectrosc. 43 (2012), 656-661. [7] R. Zhang, Y. Zhang, Z. C. Dong, S. Jiang, C. Zhang, L. G. Chen, L. Zhang, Y. Liao, J. Aizpurua, Y. Luo, J. L. Yang, J. G. Hou,

Nature 498 (2013), 82-86. [8] C. Chen, N. Hayazawa, S. Kawata, Nat. Commun. 5 (2014), 3312. [9] N. Hayazawa, T. Yano, S. Kawata, J. Raman Spectrosc. 43 (2012), 1177-1182. [10] N. Hayazawa, K. Furusawa, S. Kawata, Nanotechnology 23 (2012), 465203. [11] A. Downes, D. Salter, A. Elfick, Opt. Exp. 14 (2006), 5216-5222. [12] A. Tarun, N. Hayazawa, T. Yano, S. Kawata, J. Raman Spectrosc. 42 (2011), 992-997. [13] M. Balois, N. Hayazawa, F. C. Catalan, S. Kawata, T. Yano, T. Hayashi, Anal. Bional. Chem. In press.


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[14] T. R. Hart, R. L. Aggarwal, B. Lax, Phys. Rev. B 1 (1970), 638-642. [15] A. Tarun, N. Hayazawa, S. Kawata, Jpn. J. Appl.Phys. 49 (2010), 025003.


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Plasmonic Colloidosomes as Three-dimensional SERS Platforms with Enhanced Surface Area for Multiphase Sub-microliter Toxin Sensing G. C. PHAN-QUANG1, H. K. LEE1,2, I. Y. PHANG2, X. Y. LING1* 1 Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371. Email: [email protected] 2 Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 3 Research Link, Singapore 117602.

Colloidosomes are robust microcapsules attractive for molecular sensing owing to their characteristic micron-size, large specific surface area, and dual-phase stability. However, current colloidosome sensors are limited to qualitative fluorogenic receptor-based detection which restricts their applicability to a narrow range of molecules. Here, we introduce plasmonic colloidosomes constructed from Ag nanocubes as an emulsion-based 3D SERS platform. The colloidosomes exhibit excellent mechanical robustness, flexible size tunability, versatility to merge, and ultrasensitivity in SERS quantitation of food/industrial toxins down to sub-femtomole levels. Using just 0.5 µL of sample volumes, our plasmonic colloidosomes exhibit > 3000-fold higher SERS sensitivity over conventional suspension platform. Notably, we demonstrate the first high-throughput multiplex molecular sensing across multiple liquid phases simultaneously.

Fig. 1. Plasmonic colloidosomes constructed from Ag nanocubes are fabricated as an emulsion-based 3D SERS platform.

Acknowledgement X.Y.L. thanks Singapore National Research Foundation (NRF-NRFF2012-04) for support. H.K.L thanks the A*STAR graduate scholarship from A*STAR, Singapore.


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Designing Hot Spots over Hot Spots for More Efficient Surface-enhanced Raman Scattering (SERS) Y. LIU1*, S. PEDIREDDY1, Y. H. LEE1, R. HEGDE2, W. W. TJIU3, Y. CUI1, X. Y. LING1 1Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore e-mail. [email protected] 2 Institute of High Performance Computing, A*STAR (Agency for Science, Technology and Research), #1 Fusionopolis way, Connexis #16-16, 138632, Singapore

3 Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, 117602, Singapore

Plasmonic hot spots are typically confined to highly localized regions on metal nanoparticles. The hot spots of metal

nanoparticles have been exploited for applications in diverse fields, including plasmon-enhanced fluorescence, surface-enhanced Raman scattering (SERS), imaging, and sensing. A major challenge is to be capable of efficiently increasing the hot spot volumes on single metal nanoparticles for stronger signals in plasmon-enhanced applications.

Here, we demonstrate an efficient enhancement of the plasmonic hot spot volumes on single metal nanoparticles by selective edge gold-deposited Ag octahedra (SEGSO) using a two-step seed-mediated protocol. Such “hot spots over hot spots” strategy is attributed to our precise synthesis of plasmonic-active nanodots onto the edge and tip hot spots regions of nanoparticles. We probe the localized surface plasmon responses of the selective gold-deposited octahedra using cathodoluminescence hyperspectral imaging at the single-particle level with a spatial resolution of ~10 nm. The hot spot areas on the Ag octahedra are clearly enlarged after Au deposition, with an increase in emission intensities observed across the visible wavelengths. Single-particle surface-enhanced Raman scattering (SERS) measurements demonstrate an order of magnitude increase in the SERS enhancement factor of the SEGSO as compared to pure Ag octahedra, and a 3-fold increase as compared with non-selective gold-deposited Ag octahedra (NSEGSO). The practicality of designing hot spots selectively over hot areas is also demonstrated using theoretical simulations, where the local electromagnetic field enhancement of our edge-deposited particles is 15 times and 1.3-fold times stronger than pure Ag octahedra and facet-deposited particles, respectively. The synthetic mechanisms underlying the growth of such designer nanoparticles are also discussed together with a demonstration of the versatility of this synthetic protocol to create a library of selective gold-deposited Ag-based nanoparticles, which can be subsequently etched to cages as well as frames. Acknowledgement X.Y.L. thanks the supports from National Research Foundation, Singapore (NRF-NRFF2012-04) and Nanyang Technological University’s start-up grant. References [1] Y. Liu, S. Pedireddy, Y. H. Lee, R. S. Hegde, W. W. Tjiu, Y. Cui, X. Y. Ling, Small 10 (2014), 4940-4950. [2] E. Ringe, B. Sharma, A.-I. Henry, L. D. Marks, R. P. Van Duyne, Phys. Chem. Chem. Phys. 15 (2013), 4110-4129.

ACOVS11/ASC5 Book of Abstracts Session III - Chirality

32

SESSION III – CHIRALITY


33

Heterodyne-detected chiral vibrational SFG spectroscopy T. ISHIBASHI1* AND M. OKUNO1

1Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8571, Japan [email protected]

SFG spectroscopy can be a high sensitive detecting method to study the chirality of materials because the broken centrosymmetry due to the chirality makes the SFG process allowed even in the electric dipole approximation. We have developed the first heterodyne-detected (HD) multiplex chiral vibrational SFG (VSFG) spectrometer.1 Employing a heterodyne-detection scheme for chiral SFG spectroscopy has two advantages: (1) heterodyne detection provides the SFG susceptibility χ(

2) with the phase that carries direct information concerning the chirality of the sample; (2) the local oscillator as a standard of phase also serves as an ‘amplifier’ of the SFG field of the sample, resulting in enhancing the sensitivity of chiral SFG. The spectrometer was constructed on our multiplex VSFG spectrometer with a wide tunability of UV/visible probe wavelength.2 It has a considerable degree of flexibility in the amplitude of the local oscillator (LO) that serves as the reference of the SFG phase because a thin y-cut quart plate is used as the medium to generate LO. (Fig. 1)

As the first test for the developed spectrometer, chiral VSFG spectra from liquid R- and S-limonene were measured. The observed spectra of the enantiomers had almost the same shape with different signs, which demonstrated we have successfully discriminated them. (Fig. 2) The spectra were measured in a reflection geometry (the effective thickness ~30 nm) under the electronic nonresonance condition (visible probe wavelength: 532 nm); it is expected that detecting chiral VSFG signal by the conventional homodyne detection method at a similar experimental condition would be difficult.

To examine signal enhancement by electronic resonance effects, we measured chiral VSFG signal from acetone solutions of R- and S-binaphthol with 353-nm ultraviolet probe; the wavelength of VSFG signals be in resonant with the electronic absorption band of binaphthol located at around 335 nm. We have confirmed that the chiral VSFG signal from a solution of 20-mM concentration was detectable. The effective chiral VSFG susceptibility of the solution is estimated to be comparable to that of aligned monolayers of binaphthol, suggesting our spectrometer can measure chiral VSFG spectra of the monolayer.

HD chiral VSFG spectroscopy has been applied to proteins at air-aqueous solution interfaces.3 HD electronic-nonresonant chiral and achiral VSFG spectra at the interfaces were measured for the following proteins: bovine serum albumin, pepsin, and concanavalin A. The observed phase indicated the spectra were not from bulk solution, but from proteins layers much thinner than the effective thickness (~30 nm) of VSFG observation. The chiral spectra in the amide-I region showed variations in band positions and intensities depending on the kind of proteins, while the achiral counterparts were similar to each others. (Fig. 3). This observation suggests that the chiral VSFG signal is more informative than the achiral signal in terms of overall structures of proteins. References [1] M. Okuno and T. Ishibashi, J. Phys. Chem. Lett. 5 (2014), 2874-2878. [2] T. Maeda and T. Ishibashi, Applied Spectroscopy 61 (2007), 459-464. [3] M. Okuno and T. Ishibashi, J. Phys. Chem. C 119 (2015), 9947-9954.

Thin y-cut quartz plate

Concave mirrorFused silica plateToSpectrograph

Vis

IR

SFGAnalyzer

Polarizer

Q/2 platesample

Fig. 1. Experimental set-up for heterodyne-detected vibrational SFG

Fig. 2. Heterodyne-detected chiral VSFG spectra of liquid limonene observed at a reflection geometry. Polarization combination: psp, visible probe: 532 nm.

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Fig. 3. Chiral (upper panels) and achiral (lower panels) HD-VSFG spectra of bovine serum albumin (A), pepsin (B), and concanavalin A (C) at air-water interfaces. Solid lines are imaginary parts, and dotted lines real parts. Polarization combination of chiral and achiral are psp and ssp, respectively. Visible probe: 630 nm.


34

Circular Dichroism Nanoscopy of Metal Nanostructures H. OKAMOTO1

1Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan [email protected]

One of the most striking features of noble metal nanostructures is confinement/enhancement of optical fields due to plasmon resonances. This feature provides great potentials in high-sensitivity spectroscopy, enhanced photochemical reactions, and so forth. In the past decade, our research group has worked on visualizing the nanoscale optical fields in the periphery of the nanostructures, based on near-field optical imaging [1,2]. Another feature of plasmon resonances of metal nanostructures worth noting is their capability to generate strongly chiral optical fields in their periphery. This feature has also attracted attention of researchers in the recent years, and a number of works based on theoretical and spectroscopic investigations have been reported. We are now extending the near-field imaging study of nanoscale optical fields to local chiral optical fields generated by metal nanostructures [2].

For this purpose, we developed a near-field circular dichroism (CD) microscope [3]. The sample was irradiated by light for observation, which was modulated between left- and right-handed circular polarizations at a frequency f. The response field near the metal structure was picked up by an apertured near-field probe. By lock-in detection of the response field intensity at the modulation frequency f, we can obtain the CD signal of the sample at the position where the near-field probe locates, and scanning of the sample position relative to the probe yields the sub-wavelength CD image. We are also developing an alternative near-field CD imaging technique based on nonlinear optical process (two-photon excitation). Gold nanostructures are known to show two-photon induced photoluminescence upon excitation with femtosecond near-infrared pulses, and this feature has been utilized to visualize spatial structures of plasmon-induced confined optical fields [1,2]. By illuminating the sample with left- and right-circularly polarized femtosecond pulses from the apertured near-field probe, we can obtain local CD signal at the position of the probe tip. Preliminary results on two-dimensional gold nanostructures show that this method is also useful to obtain near-field images of local CD responses.

We prepared two-dimensional chiral gold nanostructures such as "S"-shaped structures and their enantiomeric mirrored structures, and recorded near-field CD images (Fig. 1(a)) [3,4]. Even though the far-field CD signals were found to be small (10–3 level in optical density unit) for these nanostructure samples, much enhanced local CD signals (10–1 level) were observed in the near-field CD images of the nanostructures at the same observation wavelength. The CD signals were not uniform in the individual unit nanostructure and CD signals of both directions of handedness were observed at the same time in the single unit nanostructures. An average of the local CD signal over the unit nanostructure yields a CD signal level comparable to that observed with macroscopic CD measurements (i.e., 10–2 times weakened upon averaging). This finding suggests that metal nanostructures in general give locally strong CD signals even if they macroscopically show only weak optical activity.

In fact, we found that even highly symmetric gold nanorectangles, which gave null macroscopic CD, showed strong local CD signals [5] on the near-field measurements (Fig. 1(b)). This result is important in view of the selection rules of CD measurements of materials. The conventional macroscopic CD selection rule states that only chiral materials are CD active. However, this selection rule is no longer valid for the local optical activity. The selection rule for local CD activity rather reflects the local symmetry of the material. Based on this concept, we are now trying to extend the experimental technique of plasmonic polarimetry, a novel ultrasensitive chiroptical spectroscopic method that Kadodwala and co-workers developed recently [6]. The original method of this technique utilizes chiral pairs of metal nanostructures to detect the molecular chirality. Preliminary results show that achiral metal nanostructures are also useful to detect chiral supermolecules under properly designed polarization conditions.

To get information on the origin of local optical activity, we prepared a series of gold nanostructures composed of two "C" structures with various distances between their ends (it corresponds to "S" at zero distance between the two partial structures), and measured the near-field CD images [7]. The local CD signal at the connecting region of the associating structure was enhanced when the two partial structures were close enough (~300 nm or less), and a physical contact of the two partial structures was not necessary to get locally enhanced CD. This indicates that the local CD of the two-dimensional metal nanostructure originates mainly from long-range electromagnetic interaction and not from electronic exchange between the partial structures.

The method proposed here and the information obtained may serve as a basis for design and control of chiral optical fields, which is indispensable to applications of chiral fields to analytical spectrometry, optical devices, and so forth. Acknowledgement The author is grateful to the collaborators who contributed to this work, in particular, Drs. T. Narushima, Y. Nishiyama, Mr. S. Hashiyada, Ms. A. Ishikawa, and Prof. K. Imura.

Fig. 1. Near-field CD images of (a) "S"- shaped gold nanostructure and its mirror imaged structure [4] and (b) rectangle gold nanostructure [5].


35

References [1] H. Okamoto, K. Imura, J. Phys. Chem. Lett. 4 (2013), 2230-2241. [2] H. Okamoto, T. Narushima, Y. Nishiyama, K. Imura, Phys. Chem. Chem. Phys. 17 (2015), 6192-6206. [3] T. Narushima, H. Okamoto, Phys. Chem. Chem. Phys. 15 (2013), 13805-13809. [4] T. Narushima, H. Okamoto, J. Phys. Chem. C 117 (2013), 23964-23969. [5] S. Hashiyada, T. Narushima, H. Okamoto, J. Phys. Chem. C 118 (2014), 22229-22233. [6] E. Hendry, T. Carpy, J. Johnston, M. Popland, R.. V. Mikhaylovskiy, A. J. Lapthorn, S. M. Kelly, L. D. Barron, N. Gadegaard,

M. Kadodwala, Nat. Natnotech. 5 (2010) 783-787. [7] T. Narushima, S. Hashiyada, H. Okamoto, ACS Photonics 1 (2014), 732-738.


36

Through-Space Transfer of Chiral Information Mediated by a Plasmonic Nanomaterial S. OSTOVAR POUR1*, L. ROCKS2, K. FAULDS2, D. GRAHAM2, V. PARCHANSKY3,4, P. BOUR4 AND E. W. BLANCH1

1 School of Applied Sciences, RMIT University, GPO Box 2476, Melbourne VIC 3001, Australia, [email protected] 2 Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, U.K. 3 Department of Analytical Chemistry, Institute of Chemical Technology, Technická 5, 16628 Prague, Czech Republic 4 Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo náměstí 2, 16610 Prague, Czech Republic

Nanoprobes offer significant advantages for chemical analysis, since spectroscopic detection of biomolecules is limited by the inherently weak Raman effect. In the present work, we demonstrate that silver silica nanotags can also provide enhancement for the chirally sensitive but even weaker Raman optical activity (ROA) effect, enabling highly sensitive detection of chiral biomolecules. Single nanoparticle plasmonic substrates function as achiral plasmonic nanomaterials that enable a chiral response to be transmitted from a chiral analyte to the plasmon resonance of the achiral metallic nanostructure. The chiroptical properties of these nanotags were confirmed by the measurement of mirror image surface enhanced resonance Raman optical activity (SERROA) spectra of the two enantiomers of each of ribose and tryptophan [1]. Computational modelling confirms these observations and reveals the novel chirality transfer mechanism responsible. The observation of mirror image SERROA bands originate from the SERRS spectrum of the benzotriazole dye molecules. The SERROA phenomenon measured here is fundamentally different from that responsible for our previously reported SEROA spectra of L- and D-ribose [2], since the direct interaction between the chiral molecules and the surface plasmons from metal nanoparticles in those cases was responsible for the enhancement of ROA signals. The SEROA spectral details in those previous studies also originate directly from the analyte investigated, whereas in the SERROA spectra presented in this study we observe a chiral influence on the SERRS spectrum of the benzotriazole dye.

This highly sensitive probe of chiral molecules can provide a new approach for studying biomolecules in solution [3]. This is the first report of colloidal metal nanoparticles in the form of single plasmonic substrates displaying an intrinsic chiral sensitivity once attached to a chiral molecule. Therefore, the observed mechanism is a novel and remarkable fundamental effect which can provide a new route for engineering chiral plasmonic nanomaterials for Raman-based biosensors.

References [1] S. Ostovar Pour, L. Rocks, K. Faulds, D. Graham, V. Parchansky, B. Bour, E. W. Blanch, Nature Chem., 7 (2015), 591–596. [2] S. Ostovar Pour, S. Bells, E. Blanch, Chem. Comm, 47 (2011), 4754-4756. [3] V. Mujica, Nature. Chem, 7 (2015), 543-544

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ACOVS11/ASC5 Book of Abstracts Poster Session I

37

POSTER SESSION I


38

Surface Analysis by ATR-FTIR Reveals Biogenic Oxidation of Sub-bituminous Coal by Pseudomonas fluorescens A. M. RICH1*, N. H. HAZRIN-CHONG2, C. E. MARJO1, T. DAS2, M. MANEFIELD2 1 Mark Wainwright Analytical Centre, University of New South Wales, Kensington, 2052, NSW, Australia [email protected] 2 Centre for Marine Bioinnovation, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, 2052, NSW, Australia

The bioconversion of coal to methane is increasingly becoming a worldwide interest, as methane capture and usage are now deemed beneficial to the global energy supply and economy. Pseudomonas fluorescens is a Gram-negative rod-shaped bacterium that is commonly found in the environment, particularly in soil and water, and in the bituminous coal seams in Alberta, Canada where it is observed to degrade a number of polyaromatic hydrocarbons.

Direct analysis of the colonised surface on coal using ATR-FTIR revealed bacteria-mediated oxidation at the coal surface. ATR-FTIR reveals a unique oxidation peak generated by the presence of P. fluorescens on coal, and ATR-FTIR imaging illustrated that this peak was only observed within the region of coal colonised by bacteria. Contact angle measurements and surface free energy of adhesion calculations showed that the adhesion between P. fluorescens and coal was thermodynamically favourable, and scanning electron microscopy (SEM) exhibited individual cell or monolayer cluster attachment on coal. Thus ATR-FTIR has great potential as a tool for studying coal oxidation by P. fluorescens and may well be applied to other microbe-driven modifications of coal for its rapidity and reliability. Reference [1] N. H. Hazrin-Chong, C. E. Marjo, T. Das, A. M. Rich, M. Manefield. Appl. Microbiol. Biotechnol. 98 (2014), 6443-6452


39

Infrared Spectroscopic Differentiation of the Biochemistry of Pathogenic Cellular Microparticles Released from a Cellular Model of Septic Shock J. LEE1, B. WEN2, E. A. CARTER1, V. COMBES2, G. E. GRAU2, AND P. A. LAY1

1Vibrational Spectroscopy Core Facility, The University of Sydney, Sydney, 2006, NSW, Australia [email protected] 2Vascular Immunopathology Unit, School of Medical Sciences and Marie Bashir Institute, The University of Sydney, 2006, NSW, Australia

Membrane microparticles (MPs) are sub-micron vesicles shed by cells in resting conditions and in response to various stimuli and are integral to cell-cell interactions. The first application of the non-destructive Fourier-transform infrared (FTIR) technique, to analyze MPs has revealed new insights from a lipopolysaccharide (LPS) induced, monocytic septic shock model.

Changes in the biomolecular composition of both MPs, and the monocytes from which they are released were detected. Differences in phosphatidylcholine (PC) and phosphatidylserine (PS) contents were observed in MPs released under stimulation and a higher relative concentration of RNA and α-helical structured proteins were present, compared to MPs released from resting cells. FTIR spectroscopy of the LPS-stimulated monocytes displayed changes that were consistent with those observed in the corresponding MPs from which they were released. LPS-stimulated monocytes had reduced concentrations of nucleic acids, α-helical structured proteins and PC compared to resting monocytes, but an increase in total lipids. An equally important result was that there were no observable differences (except changes in glucose and lactate due to cellular respiration) in the supernatant in which the MPs were contained.

This demonstrated that the circulating proteins and RNA released from the cells were contained almost exclusively in the circulating MPs. This new technique for probing the biomolecular compositions of MPs produced by healthy cells and during disease will be important in shedding light on the mechanisms and different roles they play in physiology and disease pathogenesis.

Acknowledgement The authors would like to thank Ms Amandine Bonhoure for her assistance with the cell culturing work in this study and the Vibrational Spectroscopy Core Facility at the University of Sydney.

Fig. 1. A FTIR spectrum of a pellet of microparticles compared to spectra of other biological samples.


40

Vibrational spectroscopy structural study of the spontaneous membrane inserting protein CLIC1 B. STORK1 AND A. DOWD1*

1University of Technology Sydney, 15 Broadway, Ultimo NSW 2007, Australia, [email protected]

Chloride intracellular channel protein 1 (CLIC1) is involved in the regulation of the cell cycle and understanding this protein more may play an important role in treating cancers. This paper presents the vibrational spectroscopy probed secondary structure of the CLIC1 protein. Results show clear indication of β-sheets within the reduced form of the protein with a peak shift from 1660 cm-1 to 1667 cm-1.

The CLIC1 is not a normal ion channel protein. It is part of a class of proteins that have both soluble and integral membrane forms. The CLIC1 protein has been located in several areas of the cell: Nuclear membrane, organelles, cytoplasm and cell membrane. Having both soluble and integral membrane forms, the CLIC1 has a variety of functions many of which are still being investigated. In its soluble form the CLIC1 protein has possible enzymatic properties and in its membrane form, ion channel properties although its function within the membrane is still unclear. It is believed the protein may be involved within cell division and as such may be involved with cancer [2]. The membrane form of CLIC1 has mainly been probed indirectly through electrophysiological experiments [1]. An ultimate goal is to determine the secondary structural form of the CLIC1 protein within a membrane. In this preliminary study we use vibrational spectroscopy to analyse the secondary structure of its soluble forms and in future the protein will be inserted into a lipid bilayer to determine the secondary structure of the membrane form.

In its soluble form the CLIC1 protein has two conformations, both oxidised dimer and reduced monomer forms. In its oxidised form CLIC1 contains random coils (~53%) and α-helix (~47%) and in its reduced form contains random coils (45%), α-helix (47%) and β-sheets (~8%) as determined by X-ray crystallography. These crystal structures correlate well with the results from the vibrational spectroscopy as seen in Figs. 1 and 2. Fig. 1 shows results obtained using Raman spectroscopy of a glassy protein deposit. This technique involves applying a 3µL drop of CLIC in buffer to a stainless steel plate, then drying the specimen under vacuum. Fig. 2 shows results obtained using ATR-FTIR absorption of protein in solution. In both instances the spectral changes indicate the presence or absence of β-sheets as the protein undergoes its redox transition in the form of a peak at 1667 cm-1 (Raman) or 1630 cm-1 (ATR-FTIR). ATR-FTIR has also been used to follow the transition over time from the oxidised form to the reduced form at 10°C as shown in Fig. 2.

Both ATR-FTIR and Raman drop cast techniques were found to yield satisfactory results for protein concentration of ~ 0.5-1 mg/mL, similar to concentrations used for circular dichroism estimation of protein structure.

CLIC1 was stored with a reducing agent of DTT(Dithiothreitol). The reducing agent TCEP (tris(2-carboxyethyl)phosphine) was also tested and appeared to have an irreversible effect, keeping the protein in its reduced form despite the addition of H2O2. We have found the optimal concentration of reducing agent to obtain CLIC1 in its reduced form. Acknowledgement I would like to thank Heba Al Khamici (UTS), A/Prof Stella Valenzuela (UTS) and Dr Joonsup Lee (USyd) for valuable technical assistance and fruitful discussions. References [1] Littler, D.R., et al., The enigma of the CLIC proteins: Ion channels, redox proteins, enzymes, scaffolding proteins? FEBS Letters, 2010. 584(10): p. 2093-2101. [2] Valenzuela, S.M., et al., The nuclear chloride ion channel NCC27 is involved in regulation of the cell cycle. Journal of Physiology-London, 2000. 529(3): p. 541-552.

Fig. 1. Spectra of reduced and oxidised soluble forms of the CLIC1 protein. The peak shift to 1667 cm-1 indicates β-sheet formation.

Fig. 2. The 2nd derivative of the ATR-FTIR signal of CLIC1 protein in solution at time = 0 (oxidised form) and 10 minutes (reduced form).


41

Characterization of polyfluorophenyl substituted organoamidoplatinum(II) compounds using some spectroscopic methods K. AL-JORANI1*, L. LIN2, G. B. DEACON1, D. MCNAUGHTON1 AND B. R. WOOD1

1Centre for Biospectroscopy, School of Chemistry, Monash University, Wellington Road, Clayton 3800, VIC, Australia [email protected] 2School of Chemistry, UNSW, Kensington, Sydney, 2052, NSW, Australia

Polyfluorophenyloraganoamidoplatinum(II) complexes including trans-N.N’-bis(polyfluorophenyl)ethane-1,2-diaminato(-1) (carboxylato) (pyridine)platinum(II) are considered as rule breakers, which means they do not conform to the structure-activity relationship of more conventional Pt (II) anticancer compounds. These types of platinum (II) complexes are sterically hindered, moisture and air stable and biologically active.

The synthesis of N,N’-bis(polyfluorophenyl)ethane-1,2-diamino(-1)(pyridine) (carboxylato)platinum(II) is achieved through a carbon dioxide elimination reaction, followed by reacting it with N,N’-bis(polyfluorophenyl)ethane-1,2-diaminato(-2) (pyridine)platinum(II) complexes which results in a carboxylic acid complex when exposed to light, This results in monoprotonation of one of amido groups and at the same time replacing one of the pyridine groups with a substituted carboxylate group with their amine ligands trans to each other[1],[2]. The product has the formula [Pt{RNCH2CH2NH}(py)(O2CR’)] and was characterized using FTIR, Raman, NMR and X-Ray crystallography. Such compounds have great potential as novel therapeutic agents and the interaction of these types of compounds with cells and isolated DNA is the subject of ongoing studies.

References [1] L. H. Lin, Ph.D. Thesis, Monash University, 1999. [2] D. Buxton,; G. Deacon,; B. Gatehouse; I. L. Grayson; R. Thomson,; D. Black,; Aust. J. Chem., 1986, 39, 2013.

Fig. 1. Molecular diagram of the unique molecule in the crystal structure of [Pt(L)(O2CC6F5)(py)] L=p-HC6F4NCH2CH2N(H)C6F4-p-H) showing the atom labelling scheme.


42

Vibrational Spectroscopic Investigation into the Binding of Platinum Complexes with DNA R. HAPUTHANTHRI1*, G. DEACON1, R. OJHA1, D. MCNAUGHTON1, E. LIPIEC 2, B. R. WOOD1 1 School of Chemistry, Faculty of Science, Monash University, Clayton Campus, Victoria, 3800, Australia. 2The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Department of Applied Spectroscopy, 31-342 Krakow, Poland.

Platinum (Pt)-based complexes, especially Pt (II) complexes such as cisplatin, which first appeared in 1970’s, have shown great success in treating a range of cancers. But the major disadvantages of cisplatin are severe toxicity and development of resistance by some cancers.1-4 It has become evident that analogues of cisplatin such as carboplatin and oxaliplatin, which appeared in clinical trials as next generation drugs, did not offer any substantial clinical advantages over cisplatin.2 Consequently, attention has turned to synthesize the nonclassical Pt anticancer drugs such as Pt (IV) complexes capable of forming a different range of DNA adducts, which could display different mechanisms of anticancer activity compared to cisplatin.2 Consequently, Pt (IV) complexes offer substantial clinical advantages over existing Pt (II) complexes. These include: (i) oral administration, (iii) reduced toxicity, and (iv) target selectivity. 2,5,6

It is well known that hydrated forms of Pt (II) anticancer drugs bind to the different nitrogen atoms in different nucleobases of the DNA by replacing one or two leaving ligands to form mono- or bifunctional adducts, respectively. In addition, they prefer to form covalent cross-links with DNA causing distortions in DNA double helix structure, and that will result in major cytotoxic lesions.

Platinum organoamides {Pt(p-HC6F4NCH2)2(py)2] (Pt103) and cis,trans,cis-[Pt(p-HC6F4NCH2)2(OH)2(py)2] (Pt103(OH)2)7 have antitumour activity both in vivo and invitro7-9 In the case of Pt103, the compound does not confirm to this structure/reactivity rules for anticancer activity for PtII compounds.10-14 in that there are no H substituents on the N-donor atoms. However similar to cisplatin, Pt103 interact with guanine residues of DNA15 and the complex may be considered a means of delivering a Cis-Pt(py))2 to the target.8 While the action of Pt (II) anticancer drugs with DNA has been well defined and characterized with many spectroscopic methods that of platinum (IV) is not yet been well defined nor characterized.1-6, 16

This project explores a systematic spectroscopic approach to investigate the binding properties of a novel range of Pt (IV) complexes to single nucleotides, oligonucleotides and DNA. Initially the project will focus on using conventional Raman, FTIR and synchrotron far-IR spectroscopy for analysis of the Pt complexes alone and their interaction with nucleotides and oligonucleotides. It is thought that Pt (IV) complexes are first reduced to their Pt (II) forms, which then binds to DNA, but according to recent findings there is no direct relationship between anticancer activity and the oxidation state of the Pt complex. Moreover, DNA nuclear bases and/or the phosphodiester backbone itself can act as a reducing agent for Pt (IV) complexes.5 This is a rather controversial hypothesis, that our FTIR study shows that no apparent reduction of Pt103(OH)2 by the PO2

- group or nucleotides. We have observed that the binding of the Pt103 complexes to dsDNA induces distortions along with a conformational change in dsDNA from a more B-DNA like form to the more compact and distorted A-DNA form using ATR-FTIR. Also we will investigate the conformational changes of DNA upon binding to drug using far-IR and Raman spectroscopy including surface-enhanced Raman spectroscopy (SERS). References [1] Hambley, T. W.; Klein, A. V. Chem. Rev. 2009, 109, 4911. [2] Foltinová, V.; Švihálková, Š.; Indlerová, L.; Horváth V.; Sova, P.; Hofmanová, J.; Janisch, R.; Kozub, K A. Scr. Med. (Brno)

2008, 81, 105. [3] Kostova, I. Recent Pat. Anticancer Drug Discov. 2006, 1, 1. [4] Galanski, M.; Keppler, B. K. Anti. Canc. Agents Med. Chem. 2007, 7, 55. [5] Hall, M. D.; Hambley, T. W. Coord. Chem. Rev. 2002, 232, 49. [6] Hummer, A. A.; Rompel, A.; Metallomics, 2013, 5, 597. [7] Guo, S-X.; Mason, D. N.; Turland, S. A.; Lawrenz, E. T.; Kelly, L. C.; Fallon, G. D.; Gatehouse, B. M.; Bond, A. M.; Deacon,

G. B.; Battle, A.; Hambley, T. W.; Rainone, S.; Webster, L. K.; Cullinane, C. J. Inorg. Biochem. 2012, 115, 226. [8] Webster, L. K.; Deacon, G. B.; Buxton, D. P.; Hillcoat, B. L.; A.M. James; Roos, I. A. G.; Thomson, R. J.; Wakelin, L. P. G.;

Williams, T. L. J. Med. Chem. 1992, 35, 3349. [9] Talarico, T.; Phillips, D. R.; Deacon, G. B.; Rainone, S.; Webster, L. K. Invest. New Drugs 1999, 17, 1. [10] T. Humbley, Chemistry Australia 1991, 58, 154. [11] Wong, E.; Giandomenico, C. M. Chem. Rev. 1999, 99, 2451. [12] Wheate, N. J.; Collins, J. G. Coord. Chem. Rev. 2003, 241, 133. [13] Quiroga, A. G. Curr. Top. Med. Chem. 2011, 11, 2613. [14] Lovejoy, K. S.; Lippard, S. J.; Dalton Trans. 2009, 48, 1065. [15] Giese, B.; Deacon, G. B.; Kuduk-Jaworska, J.; McNaughton, D. 2002, 67, 294. [16] Umapathy, P. Coord. Chem. Rev. 1989, 95, 129.


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Highly selective and sensitive detection of thrombin using aptamer-based SERS sensor L. YANG1*, C. FUI1, S. XU1 AND W. XU1

1State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Ave., Changchun 130012, P. R. China e-mail. [email protected]

Aptamer-based surface-enhanced Raman scattering (SERS) has become a promising analysis tool owing to the

advantages of simple operation, high sensitivity and nondestructive testing of SERS. Aptamers are single-stranded oligonucleotides generated by systematic evolution of ligands by exponential enrichment(SELEX) and they specifically capture the target molecules with high affinity. As can be synthesized and modified easily, aptamers have a wide prospective applications in medical diagnosis, drug molecular design, and analytical detection.

Thrombin is a kind of serine proteolytic enzyme, which converts fibrinogen to frbrin. It plays a fundamental role in facilitating and regulating blood coagulation. The concentration and activity of thrombin are important indicators to measure the blood coagulation mechanism. Therefore, it is of great significance to establish a rapid, and highly sensitive method of detecting thrombin. To date, electrochemical spectroscopy, surface plasmon resonance, and fluorescence spectroscopy have been used for thrombin detection.

We constructed a "silver triangle array - thrombin - silver nanoparticles" SERS sandwith structure using a specific aptamer identification of thrombin in the detection of thrombin. SERS has shown promise in overcoming the low sensitivity inherent to conventional Raman spectroscopy, as it is possible to obtain enormous Raman enhancement using hot spots by constructing sandwith structure. As shown in figure 1, a silver triangle plate array on a glass slide with the method of “assembly of polystyrene (PS) nanosphere monolayer - deposition of a Ag film - removing PS nanosphere”. NSL method was built for the first layer, and the thiolated aptamer and its target (thrombin) worked as a linker. The sandwich sensor was completed when the Raman-active molecule marked silver nanoparticles (AgNPs @4-MBA) was captured by the linker. To carry out the detection of thrombin, thrombin would be captured by the aptamer, forming a sandwich structure and supporting high SERS signal. However, if the thrombin was missing, the sandwich structure would be uncompleted. As a result, no SERS signal of 4-MBA would be obtained. Quantitative analysis of thrombin was performed by monitoring the intensity variation of a SERS signal of 4-MBA along with the amount of thrombin.

The methodology developed here provides important evidences for the early diagnosis of blood coagulation diseases. Besides, the extension of its application into detection of other enzymes or proteins furnishes an estimable tool aiding in the diagnosis of relative clinical diseases.

Acknowledgement This work was supported by the National Natural Science Foundation of China NSFC Grant Nos. 21373096, and National Instrumentation Program (NIP) of the Ministry of Science and Technology of China No. 2011YQ03012408. NSFC. References [1] J. Yoon, N. Choi, J. Ko, Biosens Bioelectron 47 (2013), 62–67. [2] L. Lin, S. Liu, Z. Nie, Anal. Chem. 87(2015), 4552−4559.

Fig. 1. Illustration of aptamer-based SERS sensor for thrombin detection using a Ag nano tag and Ag triangle nanoarray.


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SERS Spectroscopy for Probing Biomolecular Dynamic Changes of Cancer Cell Treated with Aptamer-drug Conjugate R. DENG1*, H. QU2, L. LIANG1, W. XU1, C. LIANG2, S. XU1 1State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Ave., Changchun 130012, China, [email protected] 2Institute of Frontier Medical Science, Jilin University, 2699 Qianjin Ave., Changchun 130021,China

Surface-enhanced Raman scattering (SERS) spectroscopy as a molecular spectroscopy can provide a high content of fingerprint spectral information of cells and tissues, which is available to in-depth understand the mechanisms of various drugs against different diseases and improve the efficiency of cancer therapy.

In this study, we tracked the specific diagnosis and treatment process of a functioned aptamer complex (TLS11a-GC-Dox) to HepG2, a human hepatocellular carcinoma cell line, by SERS spectroscopy and fluorescence imaging to explore how the chemotherapy agents affect cancer cell.

As is shown in Fig1, we first prepared Au nanoparticle nuclear targeting probes (NLS-PEG-AuNPs) as a SERS substrate. The surfaces of the AuNPs were modified with poly (ethylene glycol) (SH-PEG) and nuclear localizing signal (NLS) peptides to increase its biocompatibility and targeting efficiency (①). Then in order to specific delivery an antitumor agent (Dox) to cancer cell and improve its delivery efficiency, Dox was loaded on an aptamer (TLS11a) by intercalating its flat aromatic ring into CG sequence of TLS11a and the GC tail (②). The Dox of this conjugate could be gradually released after internalization and entered the nucleus (③). Finally, this process was detected by SERSspectroscopy and fluorescence imaging.

Targeted delivery of Dox to the HepG2 by TLS11a-GC not only can improve the specific killing efficiency for cancer cells, but also can avoid the serious side effects by their nonspecific toxicity to normal cell, and the delivery efficiency of Dox was improved greatly. SERS spectroscopy as a noninvasive and label-free analysis tool has high detection sensitivity and achieved in situ detection of live cell, so using it to track the process of TLS11a-GC-Dox conjugates treatment to HepG2, we can acquire its detailed action mechanisms. Furthermore, it can provide a concept to develop more effective methods of cancer therapy. Acknowledgement This work was supported by the National Natural Science Foundation of China NSFC Grant Nos. 21373096, and National Instrumentation Program (NIP) of the Ministry of Science and Technology of China No. 2011YQ03012408. NSFC. References [1] V. Bagalkot, O.C. Farokhzad*,Angew.Chem. Int. Ed., 45(2006), 8149 –8152. [2] L. Liang, D. Huang, H. Wang, Anal.Chem., 87(2015), 2504−2510.

Fig. 1. HepG2 treated with nuclear targeting nanoprobes and TLS11a-GC-Doxconjugate.


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Investigating the Effects of Anti-diabetic Drugs on Glucose Metabolism in Insulin-sensitive Cells by Combining Biospectroscopic Study and Biochemistry Assay A. SAFITRI1*, J. LEE2, E. A. CARTER2, K. BAMBERY3, M. J. TOBIN3, A. LEVINA1 AND P. A. LAY1,2 1School of Chemistry, The University of Sydney, Sydney, 2006 NSW, Australia, e-mail: [email protected] 2Vibrational Spectroscopy Core Facility, The University of Sydney, Sydney, 2006 NSW, Australia 3Australian Synchrotron, Clayton, 3168 Victoria, Australia

Advances in understanding the pathophysiology of diabetes and the insulin signalling mechanism provide an opportunity to develop earlier diagnosis of the disease and its complications. The current study combines spectroscopic and biochemistry approaches to investigate the effect of metals used as anti-diabetic drugs (V, Cr, Mo, and W) on glucose metabolism in insulin-sensitive tissues in order to provide new insights into the effects of these complexes on glucose uptake and metabolism at a molecular level. Here, we describe the influences of the metals used for anti-diabetic drugs in the insulin-targeted L6 cells using a combination of synchrotron radiation Fourier Transform infrared (SR-FTIR) microspetroscopy and mitochondrial-stress test assay performed on Seahorse Extracellular Flux (XF) analyser.

The SR-FTIR technique was applied to single-live L6 myoblasts. The most significant spectral differences (as shown from the second derivative spectra calculations and PLSR analyses), treatments with V(IV/V), Mo(VI), W(VI), and Cr(III) for 12 h, resulted in prominent changes in position of amide I vibrational band, sensitive to changes in protein secondary structure, the conformational transition of α-helix (1652 cm-1) to β-sheet (~1640 cm-1), also increases intensities in the amide II (~15510 cm-1) and tyrosine (~1515 cm-1) bands, indicating that those anti-diabetic metals used in this work induced phosphorylation reactions to cellular glucose metabolism of the L6 cells. These support the proposed mechanism of actions that the anti-diabetic metals used in this work inducing phosphorylation reactions to cellular glucose metabolism of the L6 cells.1 The Seahorse XF analyser is used to measure mitochondrial functions of the live cells in real time, by measuring extracellular acidification rate (ECAR) as indication for the glycolysis status, and oxygen consumption rate (OCR) as indication for the oxidative phosphorylation status, which are related to the glucose metabolism and uptake.2 The mitochondrial stress-test results suggest that anti-diabetic metals used also affected to the mitochondrial functions of cells, since L6 treated with V, Mo, W, and Cr, have significantly improved mitochondrial respirations parameters, maximum respiration and spare respiratory capacity. Acknowledgement Financial support of this work was provided by the Australian Research Council and the Australian Synchrotron. The authors acknowledge the facilities and the technical assistance of the Australian Microscopy & Microanalysis Research Facility at the Australian Centre for Microscopy & Microanalysis; of the Vibrational Spectroscopy Core Facility; and of the Molecular Biology Facility at the Bosch Institute, the University of Sydney. A. S. is grateful to Australian Awards Scholarship from Australian Government for funding of her postgraduate studies at The University of Sydney.

References [1] Levina, A.; Lay, P. A. Dalton Trans. 2011, 40, 11675-11686. [2] Seahorse Bioscience, XF Cell Mito Stress Test Kit; 2010, p 38.


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Chromophore structures in the early intermediates of light-driven chloride ion pumps S. KUBOTA1*, M. MIZUNO1, H. KANDORI2, Y. MIZUTANI1

1Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan [email protected] 2Department of Frontier Materials, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan

Fulvimarina rhodopsin (FR) is light-driven chloride ion pump, recently found in marine bacterium, Fulvimarina pelagi. FR has a retinal chromophore surrounded by seven transmembrane helices. The retinal is bound to Lys247 residue via protonated Schiff base. When FR absorbs light, the retinal chromophore isomerizes from all-trans to 13-cis form. After the isomerization, FR exhibits a photocycle reaction through several photointermediates, which are K, L, and O intermediates [1]. Structural changes of the chromophore are coupled with those of protein moiety. It is likely that the translocation pathway of chloride ion locates close to the chromophore. Accordingly, in order to understand the pump mechanism of chloride ion, it is important to reveal chromophore structures of the intermediates. In this study, we investigated chromophore structures of the unphotolyzed state and K, L intermediates of FR in nanosecond-microsecond region with time-resolved visible resonance Raman spectroscopy.

Figure 1 and 2 show time-resolved resonance Raman spectra of FR in H2O and D2O, respectively, following the photoexcitation in nanosecond-microsecond time region. The top trace in Figure 1 is a spectrum of the unphotolyzed state, where the ν(C-C), ν(C=C), and ν(C=N) Raman bands were observed at 1200, 1537, and 1629 cm−1, respectively. Below the spectrum of the unphotolyzed state, displayed are time-resolved spectra, of which delay times are shown on the left side. In these spectra, contribution of the unphotolyzed state has been subtracted. The difference spectra changed as the delay time increased. At 0.1 and 0.5 µs, a shoulder band was observed in the low frequency side of the ν(C=C) band at 1550 cm−1. The shoulder band is less prominent later than 5 µs. A spectral pattern in 1180-1200 cm−1 region changed around 5 µs. Two ν(C=N) bands were observed in 0-1 µs region. The intensity ratio of the two bands altered around 5 µs. The changes of the spectral features of the ν(C-C), ν(C=C), and ν(C=N) Raman bands mean that at least two intermediates contribute to the time-resolved spectra shown in Figure 1. Similar spectral changes were observed in the time-resolved spectra shown in Figure 2 except for the ν(C=N) band. The spectra in D2O showed a single ν(C=N) band, which was broad at 0.03 µs. It is likely that the broad feature of the ν(C=N) band results from overlap of two bands located closely to each other. The ν(C=N) band exhibited upshift around 5 µs in Figure 2.

Fig. 1. Time-resolved resonance Raman spectra of FR in 200 mM MOPS-NaOH, pH 8.0, 1 M NaCl, 0.03% β-DDM. The spectra were taken with a 2.5 mW probe beam at 475 nm. The time-resolved spectra were recorded in the presence of a 80 mW pump beam at 532 nm.

Fig. 2. Time-resolved resonance Raman spectra of FR. The experimental condition was same as that in Figure 1 except that the buffer was prepared with D2O.


47

The time-resolved spectrum at 50 µs in Figure 1 resembled the spectrum of L intermediate of halorhodopsin, which

is a chloride ion pump found in Haloarchaea [2]. The intermediate observed in the time-resolved spectrum at 50 µs is hence attributable to L intermediate. The time-resolved spectrum at 5 µs differed from that at 50 µs, suggesting that the former contains spectral contributions of an earlier intermediate, that is probably K intermediate. Its spectral component was obtained by subtraction of the time-resolved spectrum at 50 µs from that at 5 µs, which is shown in Figure 3b. Figure 3 compares spectra of the unphotolyzed state (a), K intermediate (b), and L intermediate (c) in the H2O buffer. The spectral feature in the ν(C-C) region suggests that the chromophore adopts all-trans and 13-cis forms in the unphotolyzed state and the intermediate, respectively. This is consistent with the idea that the initial step following the photoexcitation is the chromophore isomerization from all-trans to 13-cis form, which is widely accepted for microbial rhodopsins. Figure 4 compares spectra of the unphotolyzed state (a), K intermediate (b), and L intermediate (c) in the D2O buffer. The downshift due to deuteration of the 1629-, 1626-, and 1645-cm−1 bands corroborates the assignment of these Raman bands to the ν(C=N) mode and demonstrates that the chromophore in the unphotolyzed state and the intermediates are protonated. The ν(C=N) is a good maker of the hydrogen-bond strength of the protonated Schiff base of retinal because its ν(C=N) mode is coupled with the δ(NH) mode. It is well known that Schiff base with stronger hydrogen bond showed higher ν(C=N) frequency and larger deuteration shift [3]. The ν(C=N) frequency demonstrates that the hydrogen-bond of the protonated Schiff base is a little weakened upon the K formation and is considerably strengthen upon the L formation. The directions of the frequency shift of FR are same as those of HR. However, the frequency changes upon the K and L formation of FR are smaller than those of HR. This implies that the region around the Schiff base in FR undergoes smaller structural rearrangements in the early stages in the photocycle.

References [1] K. Inoue, F. H. M. Koua, Y. Kato, R. Abe-Yoshizumi, and H. Kandori, J. Phys. Chem. B 118 (2014) 11190-11199. [2] M. Mizuno, A. Nakajima, H. Kandori, Y. Mizutani, manuscript in preparation. [3] S. O. Smith, M. S. Braiman, A. B. Myers, J. A. Pardoen, J. M. L. Courtin, C. Winkel, J. Lugtenburg, R. A. Mathies, J. Am.

Chem. Soc. 109 (1987), 3108–3125.

Fig. 3. Resonance Raman spectra of FR and its intermediates in the H2O buffer. (a) Spectrum measured in the absence of the pump beam in Figure 1. (b) Spectrum resulting from subtraction of the time-resolved spectrum at 50 µs in Figure 1 from that at 5 µs to extract a spectral component of K intermediate. (c) The time-resolved spectrum at 50 µs in Figure 1.

Fig. 4. Resonance Raman spectra of FR and its intermediates in the D2O buffer. (a) Spectrum measured in the absence of the pump beam in Figure 2. (b) Spectrum resulting from subtraction of the time-resolved spectrum at 50 µs in Figure 2 from that at 5 µs to extract a spectral component of K intermediate. (c) The time-resolved spectrum at 50 µs in Figure 2.


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Long-range coupling between the chromophore and the proton donor in the K intermediate of Gloeobacter rhodopsin K. OIKAWA1*, M. MIZUNO1, H. KANDORI2 AND Y. MIZUTANI1

1Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan [email protected] 2Department of Frontier Materials, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan

Gloeobacter rhodopshin (GR) is a microbial rhodopsin found in thylakoidless cyanobacterium Gloeobacter violaceus PCC7471. GR functions as light-driven proton pump that is similar to bacteriorhodopsin (BR). Photoexcited GR return to the original state via several intermediates, called the photocycle reaction (GR → K → L → M → N → O → GR) [1]. In the course of the photocycle, the proton is transported from the cytoplasmic side to the extracellular side. The retinal Schiff base is deprotonated in the M intermediate and reprotonated in the N intermediate. In the reprotonation step, the proton donor to the Schiff base is considered to be Glu132 corresponding to Asp96 in BR. Interestingly, low temperature FTIR study proposed that Glu132 undergoes structural rearrangement in the very early stage of the photocycle (the formation of the K intermediate) [2]. This is the unique feature of GR not found in other microbial rhodopsins. Although the early structural rearrangement of Glu132 is considered important to the proton pump function, details are not known. In this study, we measured resonance Raman spectra of GR and the K intermediate of wild-type and E132D mutant GR at ambient temperature. Resonance Raman spectra of the K intermediate were obtained by power dependent spectral changes in resonance Raman spectra. Comparison of the spectra of E132D mutant with that of the wild-type GR showed that coupling is present between the Schiff base and Glu132 in the K intermediate while it is absent in the unphotolyzed state, even though Glu132 is distant from the Schiff base (ca. 11 Å based on Xanthorhodopsin, Fig. 1).

The wild-type and E132D mutant GR were expressed in E. coli and solubilized with n-dodecyl β-D-maltoside and purified by a Ni2+ affinity column. The second harmonic of a Q-switched Nd:YAG laser (wavelength, 532 nm; pulse width, 25 ns) was used for the measurements of resonance Raman spectra. We measured resonance Raman spectra in low (2 mW) and high (75 mW) power conditions.

In low power condition, a Raman spectrum contained only a spectral component of the unphotolyzed state. On the other hand, in high light condition, a Raman spectrum contained both the photolyzed state and photointermediates generated within the duration of the pulse width. By subtracting the Raman spectrum observed in low power condition from that observed in high power condition, a Raman spectrum of the photointermediates can be obtained. The intermediate formed within the duration of the pulse width, that was 25 ns, is nothing but the K intermediate in GR [1]. Thus, we obtained the Raman spectra of the photolyzed state and K intermediate of wild type and E132D GR by the measurements of low and high power conditions (Fig. 2A). The resonance Raman spectrum of the photolyzed state of E132D closely resembled that of wild-type (Fig. 2A (a) and (b)). On the other hand, the resonance Raman spectrum of the K intermediate of E132D was different from that of wild-type (Fig. 2A (c) and (d)) for 1622- and 1645-cm−1 bands, which are due to the C=N stretching mode. Fig. 2B and 2C shows expanded views in the 1600-1680 cm−1 region of the unphotolyzed state and the K intermediate, respectively. In the unphotolyzed GR, the C=N stretching band of wild-type and E132D are identical, as shown in the difference spectrum in Fig. 2B. On the other hand, for the K intermediate, the C=N stretching band of wild-type was at lower frequency than that of E132D as shown in Fig. 2C. The C=N stretching frequency is a good marker for the hydrogen-bond strength of the protonated Schiff base of retinal because its C=N stretching mode is coupled with the NH bending mode. It is well known that Schiff base with stronger hydrogen bond showed higher C=N stretching frequency and larger deuteration shift [3]. Consequently, the present resonance Raman data at ambient temperature clearly demonstrate that long range coupling is present between the Schiff base and Glu132 in the K intermediate while it is absent in the unphotolyzed state.

Fig. 1. Model of the unphotolyzed state structure of wild-type GR based on the known Xanthorhodopsin structure (PDB: 3DDL). Between E132 and S77, at least one water molecule is inserted that is in close distance to the backbone of K257.


49

References [1] M. R. M. Miranda, A. R. Choi, L. Shi, A. G. Bezerra Jr., K.-H. Jung, L. S. Brown, Biophys. J. 96 (2009) 1471–1481. [2] K. Hashimoto, A. R. Choi, Y. Furutani, K.-H. Jung, and H. Kandori, Biochemistry 49 (2010) 3343–3350. [3] S. O. Smith, M. S. Braiman, A. B. Myers, J. A. Pardoen, J. M. L. Courtin, C. Winkel, J. Lugtenburg, R. A. Mathies, J. Am.

Chem. Soc. 109 (1987), 3108–3125.

Fig. 2. Resonance Raman spectra of wild-type GR and E132D mutant. Panel A, (a) unphotolyzed state of wild-type, (b) unphotolyzed state of E132D mutant, (c) K intermediate of wild-type, and (d) K intermediate of E132D mutant. Panel B, expanded view in the 1600-1680 cm−1 region of the unphotolyzed state. Panel C, expanded view in the 1600-1680 cm−1 region of the K intermediate.


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Using Vibrational Spectroscopy and Multivariate Statistics to Quantify Seagrass Health D. CHRISTENSEN1*, B. R. WOOD1, P. COOK2, E. PAS2, J. BEARDALL3

1Centre for Biospectroscopy, School of Chemistry, Monash University, 3800, Victoria, Australia, [email protected] 2School of Chemistry, Monash University, 3800, Victoria, Australia 3School of Biology, Monash University, 3800, Victoria, Australia

Seagrasses are ecologically significant marine plants of the order Alismatales, found in shallow waters worldwide. Seagrass beds have been disappearing rapidly over the last decades, and the rate of decline is increasing alarmingly[1]. The reasons for this decline are manifold, but often have to do with anthropogenic environmental disturbance[2]. The cause(s) of a specific local decline can be inferred by measuring the carbon, nitrogen and phosphorus ratios of plant tissues, as well as 12C/13C and 14N/15N[3].

Here we present a novel method for measuring these ratios using a combination of Attenuated Total Reflectance Infrared (ATR-FTIR) spectroscopy and Partial Least Squares Regression (PLS-R) statistical analysis. Preliminary computational work was performed to determine whether isotopic substitution of carbon and nitrogen affects the position or intensity of biologically significant infrared bands. Computations on formamide (a ‘model protein’) showed significant differences in the positioning of the Amide I and Amide III bands (shifts up to -43 cm-1 observed) with carbon and nitrogen isotopic substitutions. The effects in glucose (a ‘model carbohydrate’) were more subtle, though shifts up to -13 cm-1 were observed in some complex modes. These results were used to target the statistical models with real seagrass samples.

ATR-FTIR spectra of 220 archived seagrass samples from the Water Studies Centre at Monash University were acquired using a Bruker Equinox 55. Using these spectra, PLS-R models were developed which showed good correlation with standard measurement methods (R2 values between 0.564 and 0.855), with low prediction errors when testing samples from the same species and tissue type. Each model has been optimised for best performance with different combinations of spectral pre-treatments and regression factor input.

The predictive models for elemental ratios maintain accuracy when used for samples from other species of seagrass, though the isotopic ratio models are less robust in this regard.

While these models are not yet robust enough to implement in regular fieldwork, the models are an encouraging proof of concept. Of particular significance is the prediction of carbon and nitrogen isotopic ratios, as this method promises greater cost- and labour-efficiency in comparison to the standard method of measurement. References [1] M. Waycott, C.M. Duarte, T.J.B. Carruthers, R.J. Orth, W.C. Dennison, S. Olyarnik, A. Calladine, J.W. Fourqurean, K.L. Heck

Jr, A.R. Hughes, G.A. Kendrick, W.J. Kenworthy, F.T. Short, S.L. Williams, (2009) Accelerating loss of seagrasses across the globe threatens coastal ecosystems, Proceedings of the National Academy of Sciences of the United States of America, 106 (12377-12381).

[2] R.J. Orth, T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. Fourqurean, K.L. Heck Jr, A.R. Hughes, G.A. Kendrick, W.J. Kenworthy, S. Olyarnik, F.T. Short, M. Waycott, S.L. Williams, (2006) A global crisis for seagrass ecosystems, BioScience, 56 (987-996).

[3] G. Lepoint, P. Dauby, S. Gobert, (2004) Applications of C and N stable isotopes to ecological and environmental studies in seagrass ecosystems, Marine Pollution Bulletin, 49 (887-891).


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Construction of an angle-resolved spectrometer based on rotational arms R. LYU1*, L. WANG1, X. WANG2, B. LIU2 AND Y. DAI1 1School of Physics and Mechanical & Electrical Engineering, Xiamen University, Xiamen, 361005, Fujian Province, China 2State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering,Xiamen University, Xiamen, 361005, Fujian Province, China email: [email protected]

Surface plasmon polaritons (SPPs) is attractive for researchers in the optical and (bio)chemical domains because of its ability to manipulate the light in nano-scale. SPPs resonance has been widely used in chemical and biological sensors and SPPs on metallic nanostructure is the foundation of a lot of amazing phenomenon such as surface-enhanced Raman scattering (SERS) and surface-enhanced fluorescence. (1,2) To increase the momentum of light to achieve coupling to the SPPs, researchers usually use attenuated total reflection (ATR) method in prism couplers and make use of diffraction at a diffraction grating. As a result, the modes to excite SPPs on metallic nanostructure depend on the incident angle directly, and on the other hand, the emission of SPPs is also angular dependent. Therefor we aim at constructing an angle-resolved spectrometer with large detecting range and high angular resolution as a general tool to study on properties of SPPs.

There are two main methods applied for construction of angle-resolved spectrometer—imaging on Fourier plane (3)

and rotational arms (4). The mode of imaging on Fourier plane is usually applied in SERS experiments because of its good directional property, but the low special resolution, small resoluble angle range and lack of angular adjustment limits its application in SPPs field.

To meet the requirement of large detecting range and high angular resolution, we make use of rotational arms to design an angle-resolved mechanism (see in Fig.1) and established an angle-resolved spectral measurement system based on this mechanism. This system varies incident and collecting angle from 7.6° to 90° and the angular resolution is 0.1°. Cooperating with 360° rotation of sample stage, this system is suitable for most angular experiments. To integrate functions in this angle-resolved system, we developed a software application mainly including motion control, spectra acquirement and interactive interface. Particularly, we achieved wavelength calibration for the spectrometer based on grating equation and principle of imaging to obtain accurate spectral data. Generally, researchers can operate whole system and obtain angle-resolved spectra via this software.

Since the grating coupling can excite SPPs effectively, we experimented on a one-dimensional metal grating to verify the performance of this angle-resolved system. Ultraviolet laser holographic interferometry method is used to fabricate one-dimensional periodic gold grating with about 560nm period ( ) and 40nm depth. When the dielectric is distilled water, we respectively collected spectra on the gold grating and thin gold film under incident angle from 7.6° to 42.6° by 0.9° and the same reflected angle illuminated by white light, calculated normalized intensity from the grating spectra divided by gold film spectra and obtained normalized angle-resolved reflected spectra (see in Fig.2.(a)). The relationship between wavelength and incident angle was solved when vectors were coupled under different diffractive order (see in Fig.2.(b)). Because of excitation of SPPs, absorption peaks were expected to occur in these points of the angle-resolved spectra. The experiment results were in good agreement with the theory and demonstrated that the angle-resolved spectrometer is well suited for applications on directional excitation and collection of SPPs. Acknowledgement This work was supported by the National Natural Science Foundation of China Grant No. 21373137. References [1] WL. Barnes, A. Dereux, TW. Ebbesen, Nature. 424(2003), 824-830. [2] J. Homola, SS. Yee, G. Gauglitz, Sensors and Actuators B-Chemical. 54(1999), 3-15. [3] S. A. Meyer, B. Auguie, E. C. Le Ru, P. G. Etchegoin, Journal of Physical Chemistry A. 116(2012), 1000-1007. [4] Haibo Li, Shuping Xu, Yu Liu, Yuejiao Gu, Weiqing Xu, Thin Solid Films. 520(2012), 6001-6006.

Fig. 1. Schematic diagram of angle-resolved mechanism (we conceal another rotation mechanism on which the collecting arm was fixed to show more details).

Fig. 2. (a) The dielectric is distilled water, reflected angle-resolved spectra on gold grating when illuminated by white light, (b) the dielectric is distilled water, relationship between wavelength and incident angle when the vectors were coupled on gold grating.


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A comparative study of geometries for surface enhanced Raman spectroscopy M. GEISLER1,2, A. DOWD2* AND S. ZHU2

1Technological University of Denmark, Anker Engelunds Vej 1, 2800 Kgs. Lyngby, Denmark, [email protected] 2 University of Technology, Sydney, 15 Broadway, Ultimo 2007, NSW, Australia

Surface enhanced Raman spectroscopy (SERS) has seen increased attention over the past two decades due to the method’s ability to unambiguously detect even single molecules. However, the exact nature of the signal enhancement (chemical (CHE) and/or electromagnetic (EME)) and their magnitudes is still disputed. This study compares features of different shapes for use as SERS substrates in order to estimate the chemical and electromagnetic contributions and thereby determine their relative importance.

The sample was prepared on an Si wafer and consisted of 9 areas with patterned arrays of Au features, defined with e-beam lithography, of varying geometries and size in a square grid unless otherwise noted: 0.3 µm four-pointed stars, six-pointed stars (1 µm in a hexagonal grid, 1 µm and 0.5 µm), circles (0.4 µm in a hexagonal grid, 0.5 µm and 0.2 µm), 0.5 µm squares and 0.5 µm triangles. Each area contained three different patches (~90x90 µm2) with varying distance between features (0.1 µm, 0.2 µm and 0.3 µm). The dye Rhodamine 6G (R6G) was used as analyte in this study, and the excitation wavelength was 514 nm.

Raman spectra were collected in a grid from each patch with a step size of 12 µm. Cosmic ray removal, noise filtering using a third order Savitzky-Golay filter and polynomial background correction was done on all spectra. The intensity of the peaks in the region from 1250 cm-1 to 1400 cm-1, a characteristic fingerprint region for R6G, was integrated to quantify the strength of the R6G Raman signal and then averaged over each patch to mitigate the effects of local spatial variation.

If the CHE is a significant contribution to the Raman signal, it is expected that signal strength scales with the Au coverage but is independent of Au geometry. The relative Au coverage of each patch was determined by obtaining high contrast scanning electron microscopy (SEM) images and calculating the ratio of bright pixels to the image size.

Fig. 1 shows the average peak integral area for each of the different geometries on the sample (the three with six-pointed stars and the three with circles have been averaged). The patches with six-pointed stars have a higher average signal yield by around a factor of 3 than other geometries. Fig. 2 shows the average peak area for the three different patches containing stars where the smaller stars are better by about a factor of 3 and 6 for the hexagonal and square grid, respectively. This is as expected with the EME since more electromagnetic hotspots are present for the smaller stars but could also be caused a greater field enhancement (FE) at the smaller tips. Including the distance between features, around 3 times the number of stars fit in the same patch when halving the size suggesting there is a joint contribution from the increase in number of hotspots

and the FE. A plot of the integrated peak area vs. the relative gold coverage for all

the investigated patches is shown on Fig. 3. Since each patch was approximately the same size, the relative Au coverage can be used as measure of the total gold coverage. As shown there is no direct scaling between the signal strength and the Au available for adsorption.

Of the geometries tested in this study, six-pointed stars were on average 3 times better than the others. Furthermore, the 0.5 µm stars were seen to be the best overall shape by a factor which in part can be ascribed to the increased amount of hotspots and higher FE. The CHE doesn’t contribute a significant amount to the SERS signal in the setup presented here since that would have shown a scaling with the total Au area for R6G to adsorb on.

Acknowledgement We thank Dr Joonsup Lee (University of Sydney) for assistance with Raman microspectroscopy.

Fig. 1. Average peak area for the different shapes on the sample.

Fig. 2. Average peak area for the three areas with stars. Hex and square means hexagonal and square grid, respectively.

Fig. 3. Average peak area vs. relative gold coverage on sample. Two first areas are in a hexagonal grid, the rest in a square.


53

Controlling the structure of silver nanosponges for SERS substrates D. STOCKDALE1*, A. DOWD1 1School of Mathematical and Physical Sciences, University of Technology Sydney, Broadway, 2007, NSW, Australia [email protected]

SERS (Surface Enhanced Raman Spectroscopy) is a surface dependent vibrational spectroscopic technique which has the potential to detect single molecules [1]. SERS has already had a vast impact on a variety of industries ranging from art fraud to protein investigation [2].

A variety of SERS substrates with geometries ranging from simple nanospheres to complex structures such as nanoflowers have been fabricated. A major concern surrounding SERS substrates involves the mass production of high quality SERS substrates which limits the applicability of some fabrication techniques from achieving commercially viability [3]. Nanosponges, 3-dimensional structures with nanometre sized features, have been investigated as novel SERS substrates but no explicit findings exist as to whether nanosponges can address the issues involved with SERS substrates.

Thin films of nanosponge were fabricated by magnetron co-sputtering of aluminium and silver onto a silicon wafer with aluminium content ranging from 68 at.% to 84 at.%. The samples were dealloyed in 0.2 NaOH to create silver nanosponge and transferred to a beaker containing ethanol for 2 mins to quench the reaction. The resulting SERS substrates were immediately soaked in the analyte molecule, methylene blue, at a concentration of 1x10-4 M for 24 hours and dried in air. The enhancement factor (EF) of the nanosponges were found by measuring the relative peak height of the C-C ring stretch mode at 1622 cm-1 using Raman microspectroscopy (excitation wavelength 633 nm).

The surface area of each nanosponge was estimated by soaking the nanosponges in 0.136 M methylene blue solution for 24 hours. This was followed by drying in air and desorbing the dye by placing the nanosponges into a beaker with 5 mL of deionised water. Raman measurements were used to determine if any significant dye remained on the samples. Standard solutions of methylene blue as well as the desorbed solutions were analysed using a UV-vis spectrometer and the maximum absorbance peak at 664 nm was used to determine the concentrations of the desorbed solutions.

The nanosponge formed from 84 at.% Al precursor exhibited an EF of 9.7 x104. The EF increased with aluminium content as shown in Fig. 1. Using a SEM it was observed that a higher precursor Al content resulted in a decreased distance between the ligaments (branch-like structures) of the nanosponge. This is due to the Al atoms isolating the silver atoms. During dealloying, most (but not all) the Al is leached out, leaving liberated silver atoms which diffuse over only limited distances during the formation of the nanosponge.

Hotspots are known to be the main contributors to the EF in SERS substrates. Hotspot enhancement will increase as the distance between nanosponge features decreases. Another contributor to the EF is the increase in surface area which allows for an increased number of analyte molecules to adsorb and contribute to the EF. As both the inter-ligament distance and the surface area are dependent on the precursor Al content, the nanosponge structure and its EF can be controlled. The relative contributions will be discussed in this presentation.

This research demonstrates that it is possible to control the SERS properties of silver nanosponges fabricated using the described method. The EF reported of 9.7x104 as well as the simplicity and cost of fabrication suggests that nanosponges could be commercially viable as SERS substrates.

Acknowledgement The authors would like to thank Katie McBean, Geoff McCredie, Dr Supitcha Supansomboon, Dr Mike Cortie, Dr Angus Gentle and Dr Andrew McDonagh for their technical assistance and insight.

Fig. 2 Example of an Ag nanosponge fabricated using 68% (atomic %) Al precursor by atomic percentage at 175,000x magnification

Fig. 1. Enhancement factor of Ag nanosponges using methylene blue dye as the analyte


54

References [1] E. C. Le Ru, E. Blackie,M. Meyer, andP. G. Etchegoin (2007). "Surface Enhanced Raman Scattering Enhancement Factors: A

Comprehensive Study".J. Phys. Chem. C 111(37): 13794–13803 [2] Y .Li, D. Li, Y. Cao, Y. Long, Label-free in-situ monitoring of protein tyrosine nitration in blood by surface-enhanced Raman

spectroscopy. Biosensors and Bioelectronics, 69, 1-7. [3] S. Kleinman, R. Frontiera, A. Henry, J. Dieringer, R. Duyne, “Creating, characterizing, and controlling chemistry with SERS hot

spots”. Phys. Chem. Chem. Phys., 15, 2013, 121-36


55

Conferring Temporal and Mechanical Stability to Surface-enhanced Raman Scattering (SERS) Plasmonic Security Label by Combining Atomic Layer Deposition and Polymeric Coating Techniques M. N. EKVALL1, 3, †, Y. CUI1, †, M. R. LEE1*, I. Y. PHANG3, AND X. Y. LING1

1Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371. [email protected] 2Department of Chemistry, University of York, Heslington, York, YO10 5DD, United Kingdom

3Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602. †These authors contributed equally to this work.

Surface-enhanced Raman spectroscopy (SERS) emerges as a promising technology to fabricate security labels, as commercially available techniques are becoming well known and easily replicated. However, Ag-based SERS security tags are not stable due to potential oxidation of Ag. Here we fabricate a highly stable, Ag-based patterned SERS sandwich structure coated with 5 nm alumina followed by 2 µm PMMA as a potential security label. The 5 nm alumina coating protects Ag against oxidation, allowing the substrates to exhibit long term, SERS signal intensity stability. The SERS signal intensity of protected substrates permanently exposed to high temperature or soaked in water is observed to decrease by only 30 % over a period of 55 days. Conversely, a 2 µm thick PMMA layer atop the alumina coating serves to protect the patterned substrate against physical damage; fabricated patterns on the substrate are observed to remain fully intact after a peel test. The long term SERS signal stability in various environments, as well as strong resistance to mechanical stresses highlight the potential of such substrates to be easily incorporated in a wide range of industries as next generation security labels. Acknowledgement We thank the support from National Research Foundation, Singapore (NRF-NRFF2012-04), and Nanyang Technological University’s start-up grant (M4080758). MNE thanks the support from the University of York, United Kingdom. MRL thanks the support from Nanyang Presidential Graduate Scholarship, Singapore.

References [1] F. Liu, Z. Cao, C. Tang, L. Chen and Z. Wang, ACS Nano, 2010, 4, 2643-2648 [2] Y. Han, R. Lupitskyy, T.-M. Chou, C. M. Stafford, H. Du and S. Sukhishvili, Anal. Chem., 2011, 83, 5873-5880. [3] Y. L. Mikhlin, E. A. Vishnyakova, A. S. Romanchenko, S. V. Saikova, M. N. Likhatski, Y. V. Larichev, F. V. Tuzikov, V. I.

Zaikovskii and S. M. Zharkov, Appl. Surf. Sci., 2014, 297, 75-83.


56

Charge Transfer Mechanism Study of Polymer/PC[70]BM Bulk heterojunction Films and Implications for Organic Photovoltaics J. SON1*, C. KULSHRESHTHA2, K. CHO2 AND T. JOO1 1Department of Chemistry, Pohang University of Science and Technology, Pohang, 790-784, Korea 2Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea

Organic photovoltaic (OPV) devices have advantages of low cost, light weight, flexibility and large area device applications by solution processing. OPV device is composed of blend of two different energy level semiconducting materials, donor and acceptor molecules sandwiched between the two electrodes through which their charge carriers flow by applying the voltage. In conventional inorganic semiconductors immediate creation of free charge carriers occurred with the absorption of photons, while organic semiconductor forms Frenkel type exciton which is a spatially localized tightly bound Coulombic electron-hole pair. Optical absorption in organic materials does not directly lead to free electron and hole carriers, therefore exciton should dissociate to generate an electrical current. Exiton migrates and undergoes charge transfer and charge separation at the donor-acceptor interface after charge generation in the polymer. However, some of the charge carriers are not able to succeed in breaking the Coulombic interaction and they recombine very fastly through different ways before they are extracted out to external circuit. This tends to decrease the power conversion efficiency (PCE) of OPV devices.

By this reason various research have been conducted to improve the PCE of OPV devices focusing on design and geometry of donor or acceptor molecules. In order to improve the PCE of OPV devices, understanding their mechanism is very important. However, there is still a need to explore the OPV materials in atomistic way and explain the underlying mechanism behind it. Bredas et al.[1] have tried possible explanations, and recently few modeling results have been suggested which give some insights of possible OPV mechanism.[2]

In this study, the effects of bridge central atoms of polymer molecule based on DT-fDTB polymers are used as donor material and PC[70]BM is used as acceptor material (Figure 1). The central chalcogen atom was changed in the polymer and femtosecond transient absorption experiment with 100 fs time resolution was tried in order to see the excited state population dynamics of blends. The pump wavelength was selected at 550 nm excitation and 1100 nm was used as a probe (Figure 2a). Chalcogen heteroatom blends of S and Se shows better PCE than O blend. We fitted the data kinetically with different rate constants, signifying various processes such as charge formation, separation and recombination occurring at different time scale and combined with time-resolved fluorescence data for measuring charge transfer states specifically. The measured kinetics shows intensity dependence in S and Se blends, while intensity independence in O blend (Figure 2b). The results shows inefficient charge transfer in O blend compared to S and Se blend and is affected by geminate recombination which were started quite early. In case of other two blends, S is least affected by geminate recombination and has an efficient charge transfer therefore exhibits higher PCE. Also, Se blend shows better charge separation and least nongeminate recombination but its larger size increases the charge densities in the blend due to its more interaction with PC[70]BM domains which later on were responsible for geminate recombination.

Acknowledgement We acknowledge Dr. C. Kulshreshtha for providing the materials and performing OPV device experiments. References [1] J.-L. Bredas, J. E. Norton, J. Cornil, and V. Coropceanu, Acc. Chem. Res. 42 (2009) 1691-1699. [2] S. K. Pal, T. Kesti, M. Maiti, F. Zhang, O. Inganas, S. ̈ Hellström, M. R. Andersson, F. Oswald, F. Langa, T. Osterman, T.

Pascher, A. Yartsev, V. Sundström, J. Am. Chem. Soc. 132 (2010) 12440-12451

Fig. 1. Molecular structure of donor material. Fig. 2. a. Absorption spectrum of blends.

Fig. 2. b. Transient absorption trace of each blends with different pump intensity (photons/pulse/cm2).


57

Excited State Proton Transfer Dynamics of HPTS W. HEO1*, N. UDDIN2, C. H. CHOI2 AND T. JOO1,*

1Department of Chemistry, Pohang University of Science and Technology, Pohang, 790-784, Korea 2Department of Chemistry, Kyungpook National University, Daegu, 702-701, Korea

Acid-base reaction is the most fundamental reaction in chemistry. Of Particular interest is to track molecular motions associated with the proton transfer, although obtaining direct information on the proton movement is challenging due to the lack of detection limit in temporal domain. Excited state intermolecular proton transfer (ESPT) has been and effective experimental approach to study of the proton release of photo-acids because the reaction can be coherently initiated by a ultrashort pulse. We have employed femtosecond time-resolved fluorescence (TRF) utilizing fluorescence up-conversion experiment providing 45 fs time resolution to investigate the intermolecular proton transfer reaction dynamics and potential energy surfaces associated with it.

8-hydroxypyrene-1,3,6-trisulfonate (HPTS) has a pKa close to 0 in the excited state, whereas the pKa in ground state is 7.[1] Therefore, upon excitation by 400 nm light, HPTS undergoes ESPT reaction. The emission of PA* (photo acid, protonated form) is observed at 430 nm in methanol, and the strongly red-shifted emission of PB* (photo base, deprotonated form) is dominantly observed at 510 nm in water. When dissolved in 4 M acetate buffer solution, it shows intermolecular proton transfer rate under 150 fs, the fastest ESPT reported so far.[2] The thermodynamic cycle of HPTS is characterized by Förster cycle shown in Figure 1.

Figure 2a displays the TRF spectra of HPTS following the photo excitation at 400 nm over the full spectral range, which covers PA (430 nm) and PB (510 nm) band at several time delays in 4 M acetate buffer solvent, and the PB band is clearly evident at time-zero. Interestingly, coherent wave packets were launched in the product state as well as the reactant state and their frequencies are shown in Figure 2b. The amplitude of 240 cm-1 wave packet motion changed remarkably. When the proton was moved instantaneously, the wave packet motion was largely enhanced, whereas it was absent when the reaction was forbidden by high pH condition. Molecular dynamics simulations (QM/MM) have been performed to show the detailed molecular picture of the proton transfer. Initial contraction of the distance between the donor and acceptor oxygen occurs in 30-40 fs, and the proton jumps in 10-20 fs ballistically. This theoretical result is entirely consistent with frequency of the wave packet motion (240 cm-1, 70 fs) and the experimental isotope dependence of ESPT rate. Therefore, we can conclude that the wave packet motion is directly related to the reaction.

Acknowledgement We thank N. Uddin and C. H. Choi for calculating the QM/MM simulation. References [1] L.M. Tolbert, K.M. Solntsev, Acc. Chem. Res. 35 (2002) 19-27. [2] M. Rini, D. Pines, B.-Z. Magnes, E. Pines, E.T.J. Nibbering, J. Chem. Phys. 121 (2004) 9593-9610.

Fig. 1. (a) TRF spectra of HPTS in 4 M acetate. (b) Fourier-transform results of the oscillation.

Fig. 2. Schematic of excited-state proton transfer


58

Excited State Dynamics of Three Carotenoids Observed with Femtosecond Time-Resolved Absorption and Stimulated Raman Spectroscopy in Near-IR M. ANAN1*, T. TAKAYA1 AND K. IWATA1

1Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan [email protected]

Carotenoids are a group of natural pigments that have a structure of linear polyenes. Excited-state dynamics of the carotenoids is closely related to the functions they play in the photosynthesis [1]. It has been established that the carotenoids have two principal excited singlet states, the first excited singlet (S1, 2Ag

–) state and the second excited singlet (S2, 1Bu

+) state. The carotenoids are known to undergo the rapid internal conversion from the S2 state to the S1 state following the photoexcitation from the ground state to the S2 state with visible light. We have directly observed the fast relaxation dynamics of the S2 and S1 state of β-carotene with femtosecond time-resolved absorption and stimulated Raman spectroscopy in the near-IR spectral region of 900 to 1550 nm [2]. The results show that the S2 state is converted to a vibrationally excited S1 state where only the Franck-Condon active vibrations are vibrationally “hot” at the moment of the internal conversion.

The conjugation length or terminal groups of carotenoids may affect the excited state dynamics because they modify the electronic structure or affect the interactions with surrounding molecules. In this study, we observe the excited state dynamics of three carotenoids, β-carotene, astaxanthin, and crocetin, with time-resolved near-IR absorption and stimulated Raman spectroscopy. The polyene chain of β-carotene is composed of 9 double bonds and terminated with unsubstituted ionone rings at the both ends. Astaxanthin has the same number of C=C double bonds in the polyene chain as β-carotene but terminated with ionone rings modified with a carbonyl group and a hydroxyl group. Crocetin belongs to a group of apocarotenoids that contain 20 carbon atoms. Its polyene chain is composed of 7 double bonds and terminated with carboxyl groups. We compare the energy spacing and dynamics in the excited states for the three carotenoids with different molecular structure. We examine solvent dependence of the energy spacing and dynamics for crocetin.

We photoexcited β-carotene in cyclohexane and astaxanthin in acetone by an actinic pump pulse at 480 nm and measured their time-resolved absorption spectra by a probe pulse covering the 900–1300 nm region. The recorded spectra are shown in Fig. 1. Both of the carotenoids show a strong excited-state absorption band immediately after the photoexcitation, which is assigned to the S2 state. The peak position of the S2 absorption band is located at 971 and 1042 nm for β-carotene and astaxanthin, respectively, both of which have the same number of C=C bonds. The difference is probably caused by the modification of the ionone rings with the carbonyl and hydroxyl groups. The lifetime of the S2 state is estimated to be 0.19 and 0.15 ps for β-carotene and astaxanthin, respectively, indicating that the modified ionone rings slightly accelerate the internal conversion to the S1 state. Time-resolved near-IR stimulated Raman spectra of astaxanthin show a strong band in the S2 and S1 state at 1559 and 1772 cm–1, respectively. They are assigned to the in-phase C=C stretch vibration by comparing their peak positions with those of the ground-state spontaneous Raman spectrum of β-carotene [3]. The peak positions for astaxanthin possibly indicate that the frequency of the C=C stretch vibration is slightly down-shifted from those of β-carotene [2] due to the modification.

Time-resolved near-IR absorption spectra of crocetin in acetonitrile were measured with the photoexcitation at 400 nm. The S2 absorption band of crocetin is significantly different from those of β-carotene and astaxanthin (Fig. 1). It has two distinct peaks at 936 and 1113 nm, indicating the presence of more than one final state lying closely to each other. The absorbance change of S2 crocetin is around one tenth of those for β-carotene and astaxanthin, for almost the same concentration. The lifetime of S2 crocetin is estimated to be 0.10 ps, which is shorter than β-carotene and astaxanthin. The substitution by the carboxyl groups affects the electronic structure and dynamics of the polyene chain more significantly than the substitution by the modified ionone rings. References [1] T. Polívka, V. Sundström, Chem. Rev. 104 (2004), 2021– 2071. [2] T. Takaya, K. Iwata, J. Phys. Chem. A 118 (2014), 4071–4078. [3] S. Saito, M. Tasumi, J. Raman Spectrosc. 14 (1983), 310–321.

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Fig.1. Time-resolved near-IR absorption spectra of β-carotene (left), astaxanthin (center), and crocetin (right).


59

Deterioration of the polyurethane ester PUR (ES) in the Speedo swimwear collection and monitoring the chemical aging by ART-FTIR measurement of the urethane peak C. E. MARJO1, S. GATENBY2*, A. RICH1 AND S. CHEE2 1Solid State and Elemental Analysis Unit, Mark Wainwright Analytical Centre, Room G61, Chemical Sciences Building (F10), University of NSW, Kensington, 2052, NSW, Australia 2052 2Museum of Applied arts and Sciences-Powerhouse Museum, 500 Harris Street, Ultimo, 2007, NSW, Australia [email protected]

The Museum of Applied Arts and Science’s-Powerhouse Museum has identified a deterioration problem with their 1980’s Speedo swim wear collection. The fibre composed of 20% Lycra and nylon 80% showed major loss of elasticity, was sticky to touch and oily stains were visible in the interleaving tissue papers. Fourier Transform Infrared (ATR-FTIR) Spectrometry identified the Lycra as polyurethane ester PUR (ES). Scanning electron Microscope revealed the fibres as broken, swollen and stretched. Nuclear Magnetic Resonance spectroscopy revealed the oil to be a product of the slow hydrolytic breakdown of the reactive polyurethane bond. Therefore periodic measurement using ATR- FTIR of the urethane peak would be an effective tool to monitor the chemical stability of the Lycra fibre collection. These results also demonstrated the importance of providing a dry cold and acid free environment for storage of these items.


60

Raman Spectroelectrochemistry Study of Interfacial Capacitance and Defect Density Dependent Electrochemical Activity of Single Layer Graphene J.-H. ZHONG1*, J. ZHANG1, X. JIN1, J.-Y. LIU1, D.-Y. WU1, D.-P. ZHAN1 AND B. REN1

1Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), State Key Laboratory of Physical Chemistry of Solid Surfaces, MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China, email: [email protected].

Tailoring the surface structure of an electrode material and correlating the interfacial structure and property of an electrochemical system is of critical importance for understanding and designing high performance electrochemical devices. The combination of spectroscopic and electrochemical methods, especially the in-situ methods, may allow us to gain a clear understanding about the interface.

In this work, we first showed in-situ electrochemical Raman spectroscopic study of single-layer graphene to unlock the physical origin of the interfacial capacitance of graphene.[1] The origin of the low interfacial capacitance of carbon-based materials is a long-standing puzzle. The Raman parameters of single-layer graphene, including the frequency and band width of the G band, the frequency of the 2D band, and the intensity ratio of 2D to G bands (I2D/IG), show a similar potential dependent behavior to that of the capacitance curve (Fig. 1a). The clear correlation between the Raman parameters and the capacitance can be understood by the same physical origin, i.e., the carrier concentration (n) of graphene.

We then demonstrated, by the combination of Raman spectroscopy and scanning electrochemical microscopy (SECM), that a precise control of the density of vacancy defects, introduced by Ar+ irradiation, can improve and finely tune the heterogeneous electron transfer (HET) rate of graphene.[2] By balancing the defect induced increase of density of states (DOS) and decrease of conductivity, the optimal HET rate was attained at a moderate defect density, which is in a critical state, i.e., the whole graphene sheet becomes electronically activated and, meanwhile, maintains structural integrity (Fig. 1b). The improved electrochemical activity can be understood by a high DOS near the Fermi level of defective graphene, as revealed by ab initio simulation, which enlarges the overlap between the electronic states of graphene and the redox couple. Our findings may serve as a guide to tailor the structure and properties of graphene and other ultrathin two-dimensional materials through defect density engineering.

The present work provides valuable information on the interfacial structure and properties of graphene, which may help promote the performance of graphene-based electrochemical devices. Acknowledgement Financial supports from MOST (2011YQ03012406 and 2013CB933703), NSFC (21227004, 21321062, J1310024) and MOE (IRT13036 ) are highly acknowledged. References [1] J. H. Zhong, J. Y. Liu, Q. Li, M. G. Li, Z. C. Zeng, S. Hu, D. Y. Wu, W. Cai, B. Ren, Electrochim. Acta 110(2013), 754-761. [2] J. H. Zhong, J. Zhang, X. Jin, J. Y. Liu, Q. Li, M. H. Li, W. Cai, D. Y. Wu, D. Zhan, B. Ren, J. Am. Chem. Soc. 136(2014),

16609-16617.

Fig. 1. Raman spectroelectrochemistry for studying (a) interfacial capacitance and (b) defect density dependent electrochemical activity of single layer graphene.


61

Structural Changes in 3DOM-BG Scaffold by Additional Phase Component T. CHAROENSUK1*, C. SIRISATHITKUL1 AND U. BOONYANG1

1Molecular Technology Research Unit, School of Science, Walailak University, Nakhon Si Thammarat, 80161, Thailand [email protected]

The phase component added to sodium nitrate and ferric nitrate nonahydrate in the sol-gel process affects the structure of three dimensionally ordered macroporous (3DOM) scaffold of SiO2-CaO-P2O5 bioactive glass (BG). FESEM image in Fig. 1 reveals the 3DOM scaffold inherited from the inverse opal of spherical PMMA colloidal crystal template. Clearly, the sol penetrated into the octahedral and tetrahedral holes of the structural fcc of template forms gel and becomes the bioactive glass matrix by the calcination. The three phase 3DOM-BG show that the sol can completely fill the interstitial holes (Fig. 1) whereas the Na2O phase added in the 3DOM-BG indicates the spherical surface coating by sol as the scaffold feature (Fig. 2). This phenomena similarly occurs when iron oxide component was filled. In additions, the structural 3DOM scaffolds are partially interrupted by various size of microspheres formed as phase separation. This distinct feature is shown in Fig. 3. The phase separation is probably induced by the metal salt additives. The interaction between bioactive glass precursors and the additive molecules may result in the increase of the gel phase. During the gelation process, the bioactive glass precursors coat the spherical surface of the template due to the strong precursor-template interactions. The excess precursors then move from the inside to outside and form microspherical bioactive glass. So, the distribution mostly occurs only over the external surface. The vibrational peaks analyzed by FTIR spectra confirm the compositions and purification of all 3DOM-BGs.

Acknowledgement This work is financially supported by Shell Centennial Education Fund, Shell Companies in Thailand. References [1] J. R. Jones, Acta Biomaterialia. 9 (2013), 4457-4486. [2] S. G. Rudisill, S. Shaker, D. Terzic, R. L. Maire, B.-L. Su, A. Stein, Inorg.

Chem. 54 (2015), 993-1002.

Fig. 1. 3DOM-BG scaffold of SiO2-CaO-P2O5 in which interstitial spaces of the template are filled.

Fig. 2. 3DOM-BG scaffold of SiO2-CaO-Na2O-P2O5 with spherical surface coating matrix into template.

Fig. 3. Microsphere feature formed after the SiO2-CaO-Na2O-P2O5 3DOM-BG was filled with sodium oxide and iron oxide components.


62

Photoluminescence of Carbon Nanodots G. LEE1*, T. JOO1

1Department of Chemistry, POSTECH, 77 Cheongam-Ro, Pohang, 790-784, Gyeongbuk, Korea , [email protected]

Fluorescent carbon nanodots (CNDs) have recently drawn tremendous attention due to their low toxicity, high photostability, and excellent biocompatibility compared with organic dyes and semiconductor nanodots. They are fascinating materials for the applications in optoelectronics and biomedical applications such as bioimaging, photocatalysis, sensing, light-emitting diodes, and energy conversion/storage devices.[1] However the understanding of fluorescence origins of CNDs is still unclear. Nevertheless, involvement of surface states in the radiative transition of CNDs has been proposed as the origin of fluorescence. Surface groups can introduce trap states with different energy levels, which make the photoluminescence of CNDs vary with excitation energy. Excitation-dependent emission was frequently observed for CNDs. If all surface states are completely passivated, the emission will take place only through the radiative transition of sp2 carbon, so that the photoluminescence of CNDs will not show excitation dependence. The surface states of the CNDs could be engineered so that their photoluminescence was either excitation-dependent or distinctly independent. This was achieved by changing the density of amino-groups on the CNDs surface.[2]

We synthesized two types of CNDs exhibiting excitation-independent blue emission and excitation-dependent emission by employing “water-in-oil” emulsion as a self-assembled soft template.[3] The CNDs show absorption in the UV region with a tail extending to the visible range. There may be a shoulder in the absorption attributable to the π-π* transition of the C=C bonds and the n- π* transition of C=O bonds. The CNDs synthesized with citric acid and urea show photoluminescence peaks at 400-500 nm. (Fig.1(a)) They show excitation wavelength-independent photoluminescence behaviour when the excitation wavelength is changed from 340 to 400 nm. It is remarkable that there is a vibrational progression spaced by ~1450 cm-1 corresponding to the average of D band and G band of graphene. Urea is known to form aromatic oligomers upon thermal decomposition, and aromatic-like structure might have been formed in the CNDs. On the other hand, CNDs made from citric acid and oleylamine show emission that depends on excitation wavelength. (Fig.1(b)) The photoluminescence spectra were spectrally broad with the peak wavelength ranging from 445-530 nm. Relative intensity of photoluminescence depends on the concentration of CNDs in octane solution. As the concentration of CNDs increases, the longer wavelength component of photoluminescence increases.

To further characterize the CNDs, picosecond time-resolved photoluminescence was measured by time-correlated single photon counting (TCSPC). The lifetime of CNDs by urea was less than one nanosecond and did not change significantly although detection wavelength increases. (Fig.2(a)) Meanwhile, the average lifetime of CNDs by oleylamine was a few nanoseconds and increases with increasing detection wavelength. (Fig.2(b)) The lifetime components obtained by fitting the TCSPC signals to the triple-exponential decay model imply that certain energy transfer would take place between the sp2 clusters with different energy gaps. Excitation energy dependence of the emission wavelength and intensity may be attributed to different size of nanoparticles (quantum effect) and/or different emissive traps on the CNDs surface. Absence of the excitation wavelength dependence in emission position may be attributed to their uniform size and surface chemistry.

Further study is in progress including femtosecond pump-probe coherent phonon experiment which allow more detailed structures and origin of fluorescence of CNDs. By analysing the phonon modes of the CNDs, it is expected to reveal the structure of the CNDs.

Fig. 1. Photoluminescence spectra of (a) CNDs-urea (b) CNDs-oleylamine


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References [1] S. N. Baker, G. A. Baker, Angew. Chem. Int. Ed. Engl. 49 (2010), 6726-6744. [2] X. Li, S. Zhang, S. A. Kulinich, Y. Liu, H. Zeng, Sci. Rep.4 (2014), 4976. [3] W. Kwon, G. Lee, S. Do, T. Joo, S.-W. Rhee, Small 10 (2013), 506-513.

Fig. 2. Time-resolved photoluminescence of (a) CNDs-urea (b) CNDs-oleylamine


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In Situ ATR FTIR Spectroscopic Study of Formation and Hydration of a Fucoidan/Chitosan Polyelectrolyte Multilayer T. T. M. HO1, K. E. BREMMELL2, M. KRASOWSKA1, S. V. MACWILLIAMS1, C. J. E. RICHARD1, D. N. STRINGER3, AND D. A. BEATTIE1

1Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095, Australia, [email protected] 2School of Pharmacy and Medical Sciences, University of South Australia, City East Campus, North Terrace, Adelaide, SA 5000, Australia 3Marinova Pty Ltd, 249 Kennedy Drive, Cambridge, TAS 7170, Australia.

The formation of fucoidan/chitosan-based polyelectrolyte multilayers (PEMs) has been studied with in situ Fourier transform infrared (FTIR) spectroscopy. Attenuated total reflectance (ATR) FTIR spectroscopy has been used to follow the sequential build-up of the multilayer, with peaks characteristic of each polymer being seen to increase in intensity with each respective adsorption stage. In addition, spectral processing has allowed for the extraction of spectra from individual adsorbed layers, which have been used to provide unambiguous determination of the adsorbed mass of the PEM at each stage of formation. The PEM was seen to undergo a transition in growth regimes during build-up: from exponential/supra-linear to linear. In addition, the wettability of the PEM has been probed at each stage of the build-up, using the captive bubble contact angle technique. The contact angles were uniformly low, but showed variation in value depending on the nature of the outer polymer layer, and this variation correlated with the overall percentage hydration of the PEM (determined from FTIR and quartz crystal microbalance data [1]). The nature of the hydration water within the polyelectrolyte multilayer has also been studied with FTIR spectroscopy, specifically in situ synchrotron ATR FTIR microscopy [2] of the multilayer confined between two solid surfaces. The acquired spectra have enabled the hydrogen bonding environment of the PEM hydration water to be determined. The PEM hydration water is seen to have an environment in which it is subject to fewer hydrogen bonding interactions than in bulk electrolyte solution. Acknowledgement DAB acknowledges the financial support from the Australian Research Council (ARC: Future Fellowship FT100100393). TTMH acknowledges the financial support of Division of Health Sciences and the School of Pharmacy and Medical Sciences of UniSA for her scholarship support. References [1] T.T.M.. Ho et al., Soft Matter, 11 (2015), 2110–2124. [2] D.A. Beattie et al., Langmuir, 28, (2012), 1638-1688.


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Vibrational Spectroscopic (FTIR and FT-RAMAN) Studies, Homo Lumo Analysis, NMR Chemical Shifts and Electrostatic Potential Surface of 2,3-Dibromofuran S. SESHADRI1* AND M. P. RASHEED2

1Associate Professor, Department of Physics, Urumu Dhanalakshmi College, Trichy 620019, Tamil Nadu, India e-mail [email protected] 2Research Scholar, Department of Physics, Urumu Dhanalakshmi College, Trichy 620019, Tamil Nadu, India The FTIR and Fourier Transform (FT) Raman spectra of 2,3-dibromofuran have been recorded in the region 4000-400 cm-1 and 4000-100 cm-1 respectively. The optimized geometry, frequency and intensity of vibrational bands of 2,3-dibromofuran sample were obtained by applying Density Functional Theory (DFT) using 6-311++G(d,p) basis set. The harmonic vibrational frequencies were calculated and the scaled quantum mechanical values (SQMV) have been compared with experimental FTIR and FT-Raman spectra. The subsequently calculated and observed frequencies are found to be in good agreement. The molecular electrostatic potential is carries out and the calculated HOMO and LUMO energies show that charge transfer occurs within the 2,3-dibromofuran molecule. 1H and 13C NMR chemical shifts were also calculated with GIAO approach by applying B3LYP method. References [1] M. Silverstein, G.C. Basseler, C. Morill, Spectrometric Identification of Organic Compounds, Wiley, New York, 1981P. [2] N. Sundaraganesan, H. Saleem, S. Mohan, M. Ramalingam, V. Sethuraman, Spectrochimica Acta 62A (2005) 740-751. [3] V. Krishnakumar, N. Prabavathi, Spectrochim. Acta Part A 72 (2009) 738–742.

Fig. 1. Molecular structure of 2,3,dibromofuran


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Tunable Near-infrared Femtosecond Optical Parametric Oscillator Based on a PPSLT Crystal E. YOON1* AND T. JOO1

1Department of chemistry, POSTECH, Pohang, 790-784, Gyeongbuk, South Korea [email protected]

Tunable ultrashort pulses in the near-infrared (NIR) region have been of great interest owing to the prospects for the study of the optical property of semiconducting material, multiphoton microscopy in living cell and so forth. Kerr lens mode-locked Ti:sapphire laser is an excellent light source that gives 10 nJ pulses at 800 nm with a 100 MHz repetition rate. However, further applications are hindered by their limited tuning range and high repetition rate for the study of materials.

Optical parametric oscillator (OPO) has emerged as a solid-state alternative based on the nonlinear optical process termed parametric down-conversion. An OPO synchronously pumped by a Ti:sapphire laser can provide stable femtosecond pulses tunable in the near- and mid-infrared regions. To be an excellent light source for time-resolved spectroscopy, there are three requirements; short pulse duration, high pulse energy, and variable repetition rate. However, femtosecond OPO is not widespread and the pulse energy is not high enough for many experiments. High repetition rate also restricts its usage for the study of biological and chemical systems. Cavity dumping can provide a solution to provide high pulse energy with variable repetition rate. Here, we report a synchronously pumped cavity-dumped femtosecond OPO based on periodically poled stoichiometric lithium tantalate (PPSLT), which is tunable in the near infrared region.

A schematic of the OPO is shown in Fig. 1. The OPO was synchronously pumped by Ti:sapphire laser (Tsunami, Spectra-Physics) that delivers 1 W at 800 nm at a repetition rate of 81.5 MHz. The gain medium was an Mg-doped periodically poled stoichiometric lithium tantalate with a fan-out structure (PPSLT, Oxide). The crystal is 0.5 mm wide, 7 mm high, and 0.8 mm thick, with the poling period of 22−24.3 µm distributed continuously along the crystal height. For efficient cavity dumping, a Bragg cell made of TeO2 was used instead of fused silica, which is typically used in a femtosecond cavity-dumped laser because of its low group velocity dispersion (GVD).

Fig. 2 shows the pulse energy of the cavity-dumped output as a function of repetition rate at 1120 nm and the tuning curve at the repetition rate of 250 kHz. The OPO delivers stable pulses with the pulse energy of more than 100 nJ upto 600 kHz and 70 nJ at 1 MHz. After the compensation of GVD with a pair of SF10 prisms, autocorrelation function of the OPO output was found to be 60 fs. The infrared pulses were focused in a 3 mm thick LBO crystal to generate the second harmonic. After the GVD compensation with a pair of LaLK21 prisms, the width of the autocorrelation function is 70 fs. When a Gaussian pulse shape is assumed, the widths of main peaks correspond to the pulse widths of 42 fs for the infrared and 50 fs for the visible (second harmonic), although significant wing are apparent.

In conclusion, we have fabricated a femtosecond OPO tunable in the NIR region base on a PPSLT crystal. It delivers over 100 nJ pulse energy upto 600 kHz repetition rate and short pulse duration of 42 fs. In addition to the general advantage from being in NIR region, the OPO is competitive in time-resolved spectroscopy owing to its short pulse duration, high pulse energy, and variable repetition rate. References [1] C. K. Min and T. Joo, Opt. Lett. 30 (2005), 1855-1857. [2] Q. Fu, G. Mak, and H. M. van Driel, Opt. Lett. 17 (1992), 1006-1008. [3] W. S. Pelouch, P. E. Powers, and C. L. Tang, Opt. Lett. 17 (1992), 1070-1072.

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Fig. 2. (a) Pulse energy of the cavity-dumped output as a function of repetition rate at 1120 nm, (b) pulse energy as a function of wavelength at 250 kHz repetition rate.

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Controlled Hydrothermal Synthesis of BiOCl/PbBiO2Cl, BiOCl/PbBiO2Cl/PbO, and PbBiO2Cl/PbO Composites Exhibiting Visible-Light Photocatalytic Activity C.-C. CHEN1, F.-Y. LIU1, H.-P. LIN1, W. W. LEE2,3* 1 Department of Science Education and Application, National Taichung University of Education, Taichung 403, Taiwan, ROC 2 Department of Occupational Safety and Health, Chung-Shan Medical University, Taichung 402, Taiwan. 3 Department of Occupational Medicine, Chung-Shan Medical University Hospital, Taichung 402, Taiwan E-mail: [email protected]; [email protected]

BiOCl/PbBiO2Cl, BiOCl/PbBiO2Cl/PbO, and PbBiO2Cl/PbO composites were prepared using autoclave hydrothermal methods. The composition and morphologies of the BiOCl/PbBiO2Cl, BiOCl/PbBiO2Cl/PbO, and PbBiO2Cl/PbO composites were controlled by adjusting the experimental conditions: the reaction pH value, temperature, and Pb(NO3)2/Bi(NO3)3 molar ratio. The products were characterized using XRD, SEM-EDS, HR-TEM, XPS, DR-UV-vis, BET, and UPS. The photocatalytic efficiencies of composite powder suspensions were evaluated by monitoring the crystal violet and salicylic acid concentrations.

References: [1] F. Y. Xiao, J. Xing, L. Wu, Z. P. Chen, X. L. Wang, H. G. Yang, RSC Adv., 2013, 3, 10687-10690. [2] S. Fuldner, P. Pohla, H. Bartling, S. Dankesreiter, R. Stadler, M. Gruber, A. Pfitzner, B. Konig, Green Chem., 2011, 13, 640-

643. [3] Z. Shan, W. Wang, X. Lin, H. Ding, F. Huang, J. Solid State Chem., 2008, 181, 1361-1366.

ACOVS11/ASC5 Book of Abstracts Session IV – Biospectroscopy I: Disease

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SESSION IV – BIOSPECTROSCOPY I: Disease


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Raman Spectroscopy for Practical Application in Medicine and Biology H. SATO1, B. B. ANDRIANA1 AND H. MATSUYOSHI1

1School of Science and Technology, Kwansei Gakuin University, Gakuen, Sanda, 669-1337 JAPAN, [email protected]

Biological and medical applications of Raman spectroscopy have been received keen interests by researchers for long time. It is possible to obtain information of molecular compositions of live cells and tissues in a totally noninvasive manner using Raman spectroscopy. Interference of water in Raman spectrum is much smaller than that in IR and NIR spectra. Raman spectroscopy has higher spatial resolution than these vibrational spectroscopies. Since the data of absorption spectroscopies is generally attributed to all materials existing in the light path, the spectrum reflects averaged molecular composition in the measured area. Since Raman scattered light is emission from the sample and a Raman microscope often use confocal optical configuration, the spatial resolution can be as small as diffraction limit of the optics. Yet another strong point of Raman spectroscopy in the biomedical application is that one can use a narrow optic fiber probe for measurement. It is possible to use visible or near-NIR light for Raman measurement, for which many different types of optical fibers are available.

Differentiation of stem cells was able to be detected by Raman analysis. Mouse embryonic stem (mES) cell differentiates into committed progenitor cell and fibroblast by remove/add inducing factors (Fig.1). Raman spectra of these cells were measured and processed with principal component analysis (PCA) and linier discrimination analysis (LDA). The leave-one-out validation results suggested high sensitivity and specificity of the Raman discrimination analysis (Table 1). The live cell Raman analysis was also applied for detection of endocrine disturbing chemicals. Many researchers pay attentions on effect of the endocrine disrupter in infant brain. We employed neural stem cell derived from mES and young neural cells taken from mouse infants to build an in vitro model of the neural development. The model was exposed to bisphenol A (BPA) and monitored by Raman spectroscopy. The result suggested that BPA could induce disruptions in the cell growth at any stage of the development. These results demonstrate that the Raman analysis is a powerful and useful tool to monitor the state of live cells.

A small portable Raman system with a fiber-optic Raman probe is very useful for application to human patients in clinics, even for ex vivo studies, because there is often not enough space in the hospital, although we can achieve perfect darkness for the Raman measurement. In addition, the Raman probe technology is necessary for the final goal, that is, the in-situ diagnosis of human patients. Taketani et al. succeeded in performing endoscopic Raman measurements with the BHRP for live colorectal tumor mouse models. The working distance and the size of the sampling volume were 60 and ±58 µm in the depth direction for their BHRP. They measured several Raman spectra at different points in one tumor and repeated this procedure three times, at two-week intervals. The three datasets were clearly classified into three groups in the score plot of partial least square regression (PLSR) analysis and the loading plot of factor 1 indicated a reduction in the amount of collagen in the tissues, along with the progress of the cancer.

Raman studies offer information based on statistical analyses. The certainty of a discrimination model can be confirmed with various validation methods. Thus, the reliability of the estimation in the discrimination analysis is obtained mathematically by statistical calculations and is often better than that for a conventional medical diagnosis. However, this has not attracted the attention of clinicians. One of the reasons for this is the difference in philosophy of biological and medical researchers to that of spectroscopists. A chemometrics analysis does not provide information about a specific protein or gene expression, which is the basis of knowledge for medical and biological researchers. Another reason is a problem with the robustness of the analytical model. The statistically obtained model is reliable only for that data which stays inside the supposed variation field of the model. It is either inapplicable or unreliable if the sample has not yet been experienced; in other words, the similar case of data has not been included in the model. However, such a case may actually occur in a practical situation. The tissue condition may be affected by the habits, livelihood, and condition of the patient. All of these are out of our control. To overcome these problems, it is necessary for the Raman spectroscopy to be modified to better approach biological and medical philosophy.

Raman imaging technology has inspired high expectations in biologists and medical doctors. Raman spectroscopy must be extended into an imaging technique to be a practical medical tool. Coherent antistokes Raman scattering (CARS) imaging may be the most successful Raman imaging technique. We applied a 2 wavelengths oscillated electronically tuned Ti:sapphire laser (2w-ETL) for CARS and successfully measured a stable and low-background CARS spectrum. The 2w-ETL has acousto optical tunable filter (AOTF) for wavelength selection. The AOTF is usually driven with a radio wave supplied from a driver which is controlled by a computer. When the AOTF is driven with two radio waves, it opens gates for two wavelengths. Laser lights with these wavelength are grown simultaneously in the single resonator along with the same optical pathway. Therefore, the pulsed lights with 2 different wavelengths overlap perfectly and produce the stable CARS signal. We also develop another type of Raman imaging technique, light sheet direct Raman imaging (LSDRI). The excitation light sheet supplied from a cw-background–free electronically tuned

Fig. 1: Photo images of mES (a), progenitor cell (b) and fibroblast (c).

Table 1: Result of one-leave-out evaluation for the discrimination model based on the Raman analysis.

PredictionmES Progenitor Fibroblast

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Ti:sapphire laser (BF-ETL) is inserted into the sample, and a Raman image is directly measured with a highly sensitive CCD camera (512 × 512 pixels) in the side-scattering configuration. The LSDRI system was equipped a band-pass filter in front of the CCD camera, and the filters pass through a specified Raman band. Since the BF-ETL has extremely low background emission due to spontaneous emission, no line filter is necessary. The image of the desired Raman band can be selected by tuning the frequency of the excitation laser light. Raman images of bone marrow of a rat fetus are shown in Fig. 2. The detection wavelength was 850 nm and exposure time was 15 s each for 100 mW of excitation laser lights. Since the LSDRI technique utilize spontaneous Raman scattering, it has high reproducibility in the band intensity.

Although Raman spectroscopists believe that it is a really powerful tool for biomedical studies, biologists and medical doctors rarely apply it. It suggests that there is a big chance to improve Raman spectroscopy to fit the practical use. We assume that imaging technology is one of the closest ways to the practical biomedical applications. References [1] A. Taketani, R. Hariyani, M. Ishigaki, B. B. Andriana, H. Sato, Analyst, 138 (2013), 4183-4190. [2] Y. Oshima, H. Sato, H. K. Kobayashi, T. Kimura, K. Naruse, S. Nonaka, Opt. Exp., 20 (2012), 16195-16204. [3] H. Sato, Y. Maeda, M. Ishigaki, B. B. Andriana, in Encyclopedia of Analytical Chemistry, eds R.A. Meyers, John Wiley:

Chichester. DOI: 10.1002/9780470027318.a9281, (2014). [4] H. Sato, in Emerging Raman Applications and Techniques in Biomedical and Pharmaceutical Fields, eds. P. Matousek, M. D.

Morris, Springer-Verlag, Berlin Heidelberg, (2010).

Fig. 2: Raman images of bone marrow of a rat fetus measured by LSDRI


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Diagnosis of malaria using ATR-FTIR. First trial study. D. PEREZ-GUITA1*, P. HERAUD1, T. PATCHARAPORN2, M. WONGWATTANAKUL2, P. CHATCHAWAL2, A. KHOSHMANESH1, P. JEARANAIKOON2, M. W. A. DIXON3, L. TILLEY3, D. MCNAUGHTON1, B. R. WOOD1 1Centre for Biospectroscopy, School of Chemistry, Monash University, 3800, Victoria, Australia 2Department of Clinical Chemistry, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand 3Department of Biochemistry and Molecular Biology and Bio21 Molecular, Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria 3010 Australia

Malaria is a mosquito borne disease caused by five parasitic protozoans of the genus Plasmodium. There are up to 1.200.000 fatalities per annum[1] and accurate and early diagnosis followed by the immediate treatment of the infection is essential to reduce mortality and prevent overuse of antimalarial drugs. In a previous study[2] performed on artificially infected red blood cells, we showed that Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy in combination with a partial least squares (PLS) regression modeling has the required sensitivity and ease of sample preparation to become a laboratory standard for malaria detection.

The method is simple, quick and only requires the whole blood to be spun down and the plasma and white cells removed. The red blood cells are then fixed in methanol and a 5 µL aliquot of packed cells is placed on the diamond window of the ATR-FTIR spectrometer, rapidly dried and a spectrum recorded in approximately 20 seconds.

Here we describe the first field study performed on real clinical samples from Khon Khaen (Thailand). 110 samples (81 positive and 29 negative) were measured using two Agilent 4500 spectrophotometers. Samples were obtained from male and female patients from three different regions of Thailand (see Figure 1a). Two to four replicates of each sample were measured, generating a dataset of 181 spectra (168 positives and 108 negatives). Orthogonal PLS-discriminant analysis (oPLSDA) models were performed on the fingerprint and CH3 region (2800-3200 & 800-1800 cm-1).

A cross validation (CV) performed over the average spectra of each sample indicated that the model was able to classify correctly more than 95% of the samples. A permutation test performed (as previously described [3]) indicated that the CV error obtained was statistically significant (p<0.005). Figure 1b depicts the Receiver Operating Characteristic (ROC) curve for the real and permuted classes, and indicates a satisfactory classification capability in the case of the clinical samples (area under the curve=0.9541) and is clearly different to the model obtained from the permuted classes.

The oPLSDA first loading vector indicates that the bands at 1606, 1507, 1396 and 1372 cm-1 are indicative of the parasite. Most importantly, the oPLSDA component loading of the model is similar to the oPLSDA component loading obtained using data from the earlier lab study [2], thus indicating consistent spectral differences between the infected and uninfected samples in two different experimental context: laboratory artificially infected samples measured with a Bruker 27 spectrophotometer in Melbourne and clinical samples measured with an Agilent 4500 spectrophotometer in Thailand.

The high sensitivity, low cost, ease of use, portability and robustness of the ATR-FTIR technique could see it become a standard diagnostic tool in both the clinic and remote field locations. Efforts in due course will (i) extend the sample set size in order to increase the robustness of the model and establish the actual prediction capability of the technique and (ii) investigate the molecular origin of the bands responsible of the classification. References [1] C. J. Murray, L. C Rosenfeld., S. S. Lim, K. G. Andrews, K. J. Foreman, D. Haring, N. Fullman, M. Naghavi. R. Lozano and A. D. Lopez, The Lancet, 379 (2012), 413–431. [2] A. Khoshmanesh, M. W. A. Dixon, S. Kenny, L. Tilley, D. McNaughton, B. R. Wood, Anal. Chem., 86 (2014), 4379–4386. [3] D. Pérez-Guaita, J. Kuligowski, S. Garrigues, G. Quintás and B. R. Wood The Analyst, 140 (2014), 2422–7.

a) b)

Figure 1. a) Location of the collecting sites in Thailand and b) ROC curve obtained for the cross validation of the models (leaving out all the replicates of a sample in each sub-model) for the permuted and real classes.


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Multi-modal Imaging/Mapping: Understanding Disease Processes and Their Treatments A. LEVINA1, J. B. AITKEN2, E. A. CARTER1, J. LEE1, H. H. HARRIS2, R. MAK2, M. WOOD2, H. O’RILEY2, A. I. MCLEOD2, L. WU2, B. LAI3, L. FINNEY3, S. CHEN3, S. VOGT3, D. PATERSON4, D. L. HOWARD4, M. D. DE JONGE4, M. J. TOBIN4, AND P. A. LAY1

1School of Chemistry & Vibrational Spectroscopy Core Facility, The University of Sydney, NSW, 2006, Australia [email protected] 2School of Chemistry, The University of Sydney, NSW, 2006, Australia 3 Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA 4Australian Synchrotron, 800 Blackburn Rd., Clayton VIC 3168, Australia

Probe-free multi-modal imaging (elemental and biochemical) of cells and tissues relies heavily on synchrotron techniques and provides many new insights into physiological processes and diseases and their treatment [1]. However, it is also prone to many sampling artefacts, although less so than techniques, such as fluorescence microscopy imaging, if care is taken with sampling [2]. These sampling artefacts include: chemical leaching and redistribution during fixation, changes in biochemistry due to lack of an extracellular environment for cells and/or the presence of fluorophores, precipitation of biomolecules during tissue drying, and redox and other chemical changes due to photochemistry and loss of in-vivo homeostasis on sampling.

The sampling issues have rendered many of the conclusions in the literature on applications of bioimaging questionable. This has arisen from both sampling issues themselves and the potential for chemical probes, such as fluorescent probes, to cause inherent changes in the biochemistry for which they are designed to probe. These changes include changes in biodistribution and concentrations and biomolecular docking and interactions. These will be discussed with recent examples of artefacts and a discussion of future directions.

Both published and unpublished applications of biospectroscopy and bioimaging will be discussed from areas such as diseases of the brain [2,3], cardiovascular diseases [4], cancer [5] and diabetes [6], will be discussed. These will include the results of synchrotron mapping (X-ray and FTIR) with complementary benchtop techniques (Raman and FTIR), and X-ray absorption spectroscopy.

Acknowledgement We acknowledge support from the Australian Research Council, the Australian Synchrotron. References [1] J. B. Aitken, E. A. Carter, H. Eastgate, M. J. Hackett, H. H. Harris, A. Levina, Y.-C. Lee, C.-I. Chen, B. Lai, S. Vogt, P. A. Lay, Radiat. Phys. Chem. 70 (2010), 176-184; E. A. Carter, B. S. Rayner, A. I. McLeod, L. E. Wu, C. P. Marshall, A. Levina, J. B. Aitken, P. K. Witting, B. Lai, Z. Cai, S. Vogt, Y.-C. Lee, C.-I. Chen, M. J. Tobin, H. H. Harris, P. A. Lay, Mol Biosyst. 6 (2010), 1316-1322. [2] M. J. Hackett, J. A. McQuillan, F. El-Assaad, J. B. Aitken, A. Levina, D. D. Cohen, R. Siegele, E. A. Carter, G. E. Grau, N. H. Hunt, P. A. Lay, Analyst, 136 (2011), 2941-52; M. J. Hackett, J. Lee, F. El-Assaad, J. A. McQuillan, E. A. Carter, G. E. Grau, N. H. Hunt, P. A. Lay, ACS Chem. Neurosci., 3 (2012), 1017-1024; G. N. George, I. J. Pickering, M. J. Pushie, K. Nienaber, M. J. Hackett, I. Ascone, B. Hedman, K. O. Hodgson, J. B. Aitken, A. Levina, C. Glover, P. A. Lay, J. Synchrotron Radiat. 19 (2012), 875-886. [3] M. J. Hackett, R. Siegele, F. El-Assad, J. A. McQuillan, J. B. Aitken, E. A. Carter, G. E. Grau, N. H. Hunt, D. Cohen, P. A. Lay, Nucl. Instrum. Meth. Phys. Res B, 269, (2011), 2260-2263; S. M. Y. Kong, B. K. K. Chan, J.-S. Park, K. J. Hill, J. B. Aitken, L. Cottle, H. Farghaian, A. R. Cole, P. A. Lay, C. M. Sue, A. A. Cooper, Human Mol. Gen., 23, (2014), 2816-2833. [4] P. K. Witting, H. H. Harris, B. S. Rayner, J. B. Aitken, C. T. Dillon, R. Stocker, B. Lai, Z. Cai, P. A. Lay, Biochemistry, 45, (2006), 12500-12509. [5] A. Levina, J. B. Aitken, Y. Y. Gwee, Z. J. Lim, M. Liu, A. Mitra Singharay, P. F. Wong, P. A. Lay, Chem. Eur. J. 19, (2013), 3609-3619. [6] L. Finney, Y. Chishti, T. Khare, C. Giometti, A. Levina, P. A. Lay, S. Vogt, ACS Chem. Biol., 5, (2010), 577-587; A. Levina, A. I. McLeod, P. A. Lay, Chem. Eur. J., 20, (2014),12056-12060; A. Levina, A. I. McLeod, L. E. Kremer, J. B. Aitken, C. J. Glover, B. Johannessen, P. A. Lay, Metallomics, 6, (2014), 1880-1888; L. E. Kremer, A. I. McLeod, J. B. Aitken, A. Levina, P. A. Lay, J. Inorg. Biochem., 147, (2015), 227-234; A. Levina, A. I. McLeod, A. Pulte, J. B. Aitken, P. A. Lay, Inorg. Chem., in press, doi 10.1021/ic5028948; A. Levina, A. I. McLeod, S. J. Gasparini, A. Nguyen, W. G. M. De Silva, J. B. Aitken, H. H. Harris, C. Glover, B. Johannessen, P A. Lay, Inorg. Chem., 2015, accepted.

ACOVS11/ASC5 Book of Abstracts Session V – Ultrafast and Non-Linear Spectroscopy I

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SESSION V – ULTRAFAST AND NON-LINEAR SPECTROSCOPY I


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Time-Resolved Spectroscopic Studies of Selected Aromatic Carbonyl Compounds in Aqueous Solutions D. L. PHILLIPS

University of Hong Kong, Department of Chemistry, Pokfulam Road, Hong Kong S.A.R., P. R. China [email protected]

Studies of selected aromatic carbonyl compounds like meta substituted benzophenone (BP) and anthraquinone (AQ) derivatives using product analysis investigations have been found to undergo unusual and very efficient meta activated photochemistry like photo-redox reactions, meta methyl activation reactions or in some cases photosubstitution reactions in acidic aqueous solutions.[1-5] For some of these compounds, time-resolved transient absorption spectroscopy experiments on the nanosecond time scale attempted to try to understand how the photoproducts are produced and what kinds of intermediates are involved in the photochemistry of these types of meta-substituted aromatic carbonyl and other related compounds.[1-5] Up to now there is only a small amount or no information for the process occurring on the ultrafast time scales or structural information about the electronic excited states and intermediates from time-resolved vibrational spectroscopy for the aromatic carbonyl compounds of interest. This has made it hard to gain a better understanding of the intermediates and reaction mechanisms associated with the intriguing and unusual meta-effect photochemistry of BP and AQ derivatives that lead to unexpected reaction products in acidic aqueous solutions.[1-5]

In this presentation, results from time-resolved spectroscopy experiments from femtoseconds to final product formation that directly probe and characterize the electronic excited states and intermediate species for the meta-substituted aromatic carbonyl compounds of interest will be described.[6-8] These time-resolved spectroscopy results (such as femtosecond and nanosecond time-resolved transient absorption and picosecond and nanosecond time-resolved resonance Raman spectra) add a great deal of new information about the clear identity and properties of the intermediates and the reaction mechanisms for the meta-substituted aromatic compounds studied and give new insight into how the photochemistry of interest is able to occur in aqueous and/or acid aqueous solutions. These new results also help account for why the presence of water is necessary for the photoredox and photosubstitution reactions to take place in the compounds investigated. The time-resolved spectroscopy results for selected meta-substituted BP and AQ derivatives indicates that the unusual and efficient meta-effect photochemistry observed results from a key reactive protonated triplet state intermediate that undergoes efficient deprotonation at the meta distal group which leads to new kinds of photochemical outcomes like photo-redox or photo-substitution at the meta-moiety.[6-8] Related substituent effects on the chemical reactivity of selected aromatic carbonyl compounds have also been explored and we report a BP derivative that is hundreds of times more reactive towards hydrogen abstraction of alcohols than BP and which can be used to cleanly prepare cross coupling products with little or no dimerization products. This indicates that the cross coupling of the initially prepared radicals is so fast that little or no radical intermediates are able to escape the solvent cage so as to make noticeable amounts of diffusion related products. Acknowledgement This work was supported by grants from the Research Grants Council of Hong Kong (HKU 7035/13P) to DLP. Partial support from the Grants Committee Areas of Excellence Scheme (AoE/P-03/08) and the Special Equipment Grant (SEG HKU/07) are also gratefully acknowledged. References [1] M. Lukeman, M. Xu, P. Wan, Chem. Commun. 2 (2002), 136-137. [2] L. A. Huck, P. Wan, Org. Lett. 6 (2004), 1797-1799. [3] M. Devin, M. Lukeman, L. Dan, P. Wan, Org. Lett. 7 (2005), 3387-3389. [4] N. Basarić, D. Mitchell, P. Wan, Can. J. Chem. 85 (2007), 561-571. [5] Y. Y. Hou, P. Wan, Photochem. Photobiol. Sci. 7 (2008), 588-596. [6] J. Ma, M. D. Li, D. L. Phillips, P. Wan, J. Org. Chem. 76 (2011), 3710-3719. [7] J. Ma, T. Su, M. D. Li, L. L. Du, J. Q. Huang, X. G. Guan, D. L. Phillips, J. Am. Chem. Soc. 134 (2012), 14858-14868. [8] J. Ma, T. Su, M. D. Li, X. T. Zhang, J. Q. Huang , D. L. Phillips, J. Org. Chem.78 (2013), 3710-3719.


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Ultrafast multi-dimensional electronic spectroscopy and its applications to the study of Light Harvesting Complexes H. -S. TAN

Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371 [email protected] Recently, there has been much interest in the application of ultrafast multi-dimensional electronic spectroscopy to the study of Light Harvesting Complexes [1]. We will review the basic principles of multi-dimensional electronic spectroscopy.

We report on our application of ultrafast two-dimensional (2DES) and three-dimensional (3DES) spectroscopies [2-4] to the study of the excitonic energy transfer (EET) processes in LHC II light harvesting complexes.

We present results in our studies of the ultrafast dynamics of energy transfer from Chl b to Chl a band in trimeric and aggregated LHCII using two-dimensional electronic spectroscopy (2DES) [5,6]. Global fitting analysis of the 2D spectra revealed similarities and differences between the kinetic components of LHCII trimers and aggregates. The 2D decay-associated spectra resulting from global analysis resolved an intermediate mid energy state of which the decay pathway depends on the physical state of LHCII.

The EET process in light harvesting complexes is typically

complex and proceeds in a multistep fashion. In 2DES, the spectra are presented in two frequency dimensions: one excitation frequency and one of the emission frequency. The crosspeaks on the 2D spectra correlates the donor exciton to the acceptor exciton. As this is a two point correlation, multistep processes can only be indirectly observed. In 3DES, with an additional frequency axis, three-step processes can be directly observed. A crosspeak on a 3D spectrum at (ωa , ωb , ωc) will denote exciton a transferring energy to exciton c, via an intermediate exciton b. We have performed 3DES on LHCII trimers, and directly observed for the first time multistep EET process [7]. Acknowledgement This work is supported by a joint grant from the Singapore Agency for Science, Technology and Research, A*STAR and the Hungarian National Innovation Office (A*STAR SERC Grant No. 102-149-0153; NIH-A*STAR TET_10-1-2011-027) and the Singapore National Research Foundation (NRF-CRP5-2009-04). References [1] G.S. Schlau-Cohen, A. Ishizaki, G.R. Fleming, Chem. Phys. 386 (2011), 1–22. [2] Z. Zhang, K.L. Wells, E.W.J. Hyland, H.–S. Tan, Chem. Phys. Lett. 550 (2012), 156-161. [3] Z. Zhang, K.L. Wells, H.–S. Tan, Opt. Lett. 37 (2012), 5058-5060. [4] Z. Zhang, K.L. Wells, M.T. Seidel and H.-S. Tan., J. Phys. Chem. B, 117 (49) (2013), 15369–15385. [5] K.L. Wells, P.H. Lambrev, Z. Zhang, G. Garab, H.-S. Tan, Phys. Chem. Chem. Phys. 16 (2014), 11640-11646. [6] M. M. Enriquez, P. Ahktar, C. Zhang, G. Garab, P.H. Lambrev and H.-S. Tan., J. Chem. Phys. 142 (2015), 212432. [7] Z. Zhang, P.H. Lambrev, K.L. Wells, G. Garab, H.-S. Tan, Nature Communications (2015).

Fig. 3. Schematic of experimental setup for the 5th order 3D electronic spectroscopy (3DES).

Fig. 4. 3DES spectrum of LHCII. Spectrum recorded at population times t2 = 0.3 ps and t4 = 800 fs. The isosurface represents amplitude values of 0.1 relative to the global maximum.


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Ultrafast Charge Migration and Coherent Phonon Dynamics Driven by Excitonic Quantum Coherence in CdSe Nanocrystals S. DONG1, D. TRIVEDI2, S. CHAKRABORTTY3, T. KOBAYASHI4,5,6,7, Y. CHAN3,8, O. V. PREZHDO9, AND Z.-H. LOH1

1Division of Chemistry and Biological Chemistry, and Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, S637371, Singapore [email protected] 2Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, United States 3Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore 4Advanced Ultrafast Laser Research Center, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan 5JST, CREST, K’Gobancho, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan 6Department of Electrophysics, National Chiao-Tung University, Hsinchu 300, Taiwan 7Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0971, Japan 8Institute of Materials Research and Engineering A*STAR, 3 Research Link, Singapore 117602, Singapore 9Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States

Recent observations of excitonic coherences within photosynthetic complexes at ambient temperature have spurred debate about the role of quantum coherences on energy transport in biological light harvesting. Here, we employ optical pump-probe spectroscopy with few-cycle pulses to investigate excitonic coherences in CdSe semiconductor nanocrystals (Fig. 1a), which represent a prototypical artificial light harvesting system. The high-quality data allowed the first reconstruction of charge migration in a nanoscale system that is driven solely by excitonic coherence, without the participation of nuclear motion. Coherent charge migration is found to occur within the CdSe nanocrystal over 1-nm-length scales (Fig. 1b and 1c) with rates that can potentially exceed 1 Å/fs. Results of temperature-dependent measurements suggest that decoherence of excitonic motion is induced predominantly by the complex electronic structure of the nanocrystal rather than its phonon bath. The generation of the excitonic superposition is also found to influence the behavior of the coherent phonons. At 77 K, for example, charge migration is found to suppress the LO phonon amplitude by >10× and enhance the LA phonon amplitude by ~2×. Our experimental data is supported by ab initio molecular dynamics simulations.

Fig. 1. (a) Femtosecond time-resolved differential transmission spectra as a function of time delay. The observed amplitude modulation is a spectral signature of excitonic coherence. (b) and (c) show the reconstructed radial distribution functions at inner (b) and outer (c) turning points of the hole radial wave packet. The classical orbit period is given by , where is the energy gap between the – excitonic states that comprise the superposition. The radius of the nanocrystal used in this work is 3.05 nm, for which is 44 fs. Acknowledgement This work is supported by a NTU start-up grant, the A*Star Science and Engineering Research Council Public Sector Funding (122-PSF-0011), and the award of a Nanyang Assistant Professorship to Z.-H.L. O.V.P. acknowledges financial support from the U.S. National Science Foundation (CHE-1300118). Y.C. acknowledges financial support from the National Research Foundation (NRF) Competitive Research Programme (NRF-CRP8-2011-07) and the NRF Singapore-Berkeley Research Initiative for Sustainable Energy (SinBerRISE) CREATE Programme.


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Watching energy flow in proteins Y. MIZUTANI1, M. KONDOH1, N. FUJII1, M. MIYAMOTO1, M. MIZUNO1, AND H. ISHIKAWA1 1 Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan e-mail. [email protected]

Flow of excess energy from a reacting molecule is one of the key issues for understanding how chemical reactions take place in the condensed phases, such as liquid and protein. Excess energy is often deposited in many degrees of freedom right after photoreactions or internal conversions. Many experiments have been performed to study the dissipation processes of excess energy after photoexciting the chromophores. Particularly, hemeproteins have been extensively studied because the heme exhibits ultrafast internal conversion (< 100 fs) and, hence, large amount of excess energy is deposited by photoexcitation. The cooling processes of the heme [1] and the heating of solvent molecules [2] have been well characterized by ultrafast spectroscopy. However, the energy flow within protein moiety has not been directly observed.

Recently, we succeeded in observing the vibrational energy flow in photoexcited cytochrome c by using anti-Stokes ultraviolet resonance Raman (UVRR) spectroscopy [3]. UVRR spectroscopy can selectively monitor Raman bands of aromatic amino acid residues, such as tryptophan (Trp), tyrosine (Tyr), and phenylalanine (Phe) [4]. Because anti-Stokes Raman intensity reflects the population in vibrationally excited states, it can be a direct probe of vibrational energy of residues in a protein. In many hemeprotein, the distance and relative orientation between heme and the amino acid residues are well characterized based on X-ray crystallographic data. Because the distance can be as long as 20 Å, it is possible to observe how the energy deposited to the heme migrates to surrounding residues by measuring the anti-Stokes band intensities of the residues. Accordingly, studies using the present technique based on hemeproteins will provide us new insights for understanding the mechanism of vibrational energy transfer in condensed phases.

In this study, we investigated distance dependence of energy flow from the heme to discuss the energy transport mechanism in protein moiety, measuring time-resolved anti-Stokes UVRR spectra of myoglobin [5] and cytochrome b562 mutants upon the excitation of heme. Time-resolved anti-Stokes UVRR spectroscopy is applicable to study time- and space-resolved observation of energy migration in protein by the combination of site-directed mutagenesis. The position of Trp residue can be changed in the protein by amino acid substitution as shown in Figure 1. Thus, by comparing data of mutants in which the distances between the heme and Trp are different, we can map the energy flow in protein. We prepared several mutants in which a Trp residue located at different distance from the heme. For all mutants we studied, anti-Stokes bands attributed to the Trp residue at 760 (W18 band) and 1010 cm−1 (W16 band) were observed. These bands appeared in a few picoseconds after the photoexcitation and diminished in tens of picoseconds. The increase and decrease of band intensities can be ascribed to energy transfer from the heme and energy release to the surrounding residues, respectively. In the time-resolved spectra, the anti-Stokes band intensities due to the transient species became lower as the distance between the Trp residue and the heme was longer. This is consistent with the simple idea that spatial density of the excess energy decreases as the energy diffuses. The time evolution of anti-Stokes intensities were compared among the mutants. The intensity rise of the anti-Stokes band became slower as the distance between the Trp residue and the heme was longer. This means that it takes longer time for the excess energy to arrive at the position farer from the heme. We analysed the data to see if a classical heat transport model reproduces the data. The model was not able to reproduce whole set of the observed anti-Stokes data, suggesting that the molecular-level description is necessary to account for the energy transport in the protein.

Fig. 1. Crystallographic structure of sperm whale Mb. (a) Wild-type Mb. The two original Trp residues are shown as space filling spheres in yellow colour, and the protein as ribbon. (b) Mutant Mb. The heme and probe Trp residues are modelled as space filling spheres in red and cyan colour, respectively. The center-to-center distances between the heme and Trp residue are indicated. The figures were produced with PyMOL (http://www.pymol.org/).


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Despite extensive experimental and theoretical investigations, intermolecular vibrational energy transfer between two different polyatomic molecules in solution has received very little attention due to experimental difficulties. Vibrational energy transfer between a solute molecule and solvent molecules has been studied by various pump-probe techniques [6-8]. For instance, Iwaki and Dlott studied the vibrational energy relaxation of a methanol-CCl4 mixture using mid-IR pump and anti-Stokes Raman probe experiments [7]. They excited the C-H and O-H stretching modes of methanol and probed the low-wave number Raman bands of solvent. In these studies, however, the averages of energy transfer processes to many solvent molecules were observed. Selective observation is impossible for energy transfer between a specific pair of solute and solvent molecules for which distance and orientation are well-defined.

An attempt was made to observe the energy transfer between a pair of molecules by utilizing molecular heater-thermometer integrated systems, where two different molecules, namely, a heater that absorbs the visible radiation and a thermometer that probes the temperature by changing the absorption in the vicinity of its hot band, are brought into proximity by covalently linking the two discrete molecules [9-11]. However, for systems with longer linkers, the flexibility of the linker makes it difficult to keep the distance and relative orientation between the heater and thermometer molecules well-defined.

In hemeprotein, the distance and relative orientation between heme and the amino acid residues are well characterized based on X-ray crystallographic data, and the distance between heme and the amino acid residues can be as long as 20 Å. It is possible to observe how the energy deposited to the heme migrates to surrounding residues by measuring the anti-Stokes band intensities of the residues. Excess energy as great as 25000 cm−1 can be deposited into the heme by photoexcitation via the Soret transition. Moreover, we can investigate distance dependence of energy flow from the heme by introducing the probe residue at the desired position by site-directed mutagenesis. Accordingly, studies using the present technique based on hemeproteins will provide us new insights for understanding the mechanism of vibrational energy transfer in condensed phases.

The present technique of energy mapping based on the anti-Stokes UVRR intensity of Trp residues fully utilizes two unique characteristics of Raman spectroscopy, site-specific observation by resonance Raman effect and selective observation of vibrationally excited population by anti-Stokes scattering. Our methodology when systematically applied across proteins with different structural motifs can provide increased understanding of the energy flow in protein. References [1] Y. Mizutani, and T. Kitagawa, Science 278, 443-446 (1997). [2] T. Lian, B. Locke, Y. Kholodenko, and R. M. Hochstrasser, J. Phys. Chem. 98, 11648-11656 (1994). [3] N. Fujii, M. Mizuno, and Y. Mizutani, J. Phys. Chem. B 115, 13057–13064 (2011). [4] S. A. Asher, Ann. Rev. Phys. Chem. 39, 537-588 (1988). [5] N. Fujii, M. Mizuno, H. Ishikawa, and Y. Mizutani, J. Phys. Chem. Lett. 5, 3269–3273 (2014). [6] J. C. Deàk, Y. Pang, T. D. Sechler, Z. Wang, and D. D. Dlott, Science 306, 473-476 (2004). [7] L. K. Iwaki and D. D. Dlott, J. Phys. Chem. A 104, 9101-9112 (2000). [8] G. Seifert, R. Zurl, T. Patzlaff, and H. Graener, J. Chem. Phys. 112, 6349-6354 (2000). [9] T. Okazaki, N. Hirota, T. Nagata, A. Osuka, and M. Terazima, J. Am. Chem. Soc. 121, 5079-5080 (1999). [10] T. Okazaki, N. Hirota, T. Nagata, A. Osuka, and M. Terazima, J. Phys. Chem. A 103, 9591-9600 (1999). [11] S. Velate, E. O. Danilov, and M. A. J. Rodgers, J. Phys. Chem. A 109, 8969-8975 (2005).


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Structural Change Dynamics of Oligomers of Gold(I) Complex Observed by Ultrafast Spectroscopy M. IWAMURA1, K. NOZAKI1 S. TAKEUCHI2 AND T. TAHARA2

1University of Toyama, 3190 Gofuku., Toyama, 930-8555, Japan [email protected] 2Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan

Transition metal complexes have unique electronic and magnetic properties and play important roles in various systems. One of the key photochemical properties of metal complexes is the structural change induced by photoexcitation. As is well known, the structure of transition metal complexes directly reflects the configuration of d electrons, so that excitation of d electron often induces a substantial structural change. Because such a photoinduced structural change is an essential component of photophysics and photochemistry of metal complexes, knowledge of the dynamics and mechanism is indispensable for profound understanding of the properties of metal complexes. In this decade, we have studied about photo-induced structural changes of typical d10 metal complexes, such as copper(I)[1] and gold(I) complexes[2], using ultrafast time-resolved spectroscopic techniques in the visible region. In this paper, our recent studies researching structural dynamics of gold(I) complexes in solutions are described.

It is known that an aqueous solution of dicyanoaurate ([Au(CN)2

−]) contains oligomers such as dimer and trimer when the concentration is higher than ~0.01 mol/dm3 due to attractive forces among gold atoms (e.g. aurophilic interactions) [3]. In the case of photo-excited states of the oligomers, it has been believed that tight covalent Au-Au bonds are formed in the oligomers by the electronic transition from the anti-bonding dσ* orbital to the bonding pσ orbital (Fig. 1) [4] . Thus, it is expected that large structural changes would occur in the excited state of the oligomers related to the tight gold-gold bond generation. In this work, we performed selective excitations of the dimer, trimer and high oligomerized species in aqueous solutions by choosing excitation wavelengths and conditions of the solutions such as their concentrations. The femto-second transient absorption spectral change related to the gold-gold bond generation and relevant structural changes of these oligomers were successively recorded.

When the selective excitation of the dimers ([Au(CN)2−]2) in

aqueous solution was performed, a transient absorption band appeared at 550 nm. The observed signal showed an oscillation, reflecting coherent nuclear wavepacket motion induced by photoexcitation. Its frequencies accorded very well with the Au-Au stretch vibrations in the excited-state dimer calculated by DFT, which confirms the observed transient absorption is assignable to that of the dimer as well as gold-gold bond generation in the excited state. The absorption band decayed with the same time constant as the phosphorescence lifetime of the dimer (26 ps).

In the case of selective excitation of the trimer ([Au(CN)2−]3),

transient absorption band was observed around 600 nm. (Fig. 2) [2] The transient absorption also exhibited a clear modulation (Inset in Fig.1), of which frequencies were very close to those of Au-Au stretching vibrations in the excited-state trimer. This transient absorption exhibited a significant intensity increase (τ = 2.1 ps) in the early picosecond time region. DFT/TDDFT calculations revealed that the spectral changes are ascribed to the structural change from the bent to linear structures. Such significant intensity increase of the transient absorption was absent in the case of the dimer, which confirms the assignment of this process to the change of the structure from bent to linear in the trimer. Oligomers which are larger than a trimer ([Au(CN)2

−]n (n > 3) ) are rarely found in the ground state even in aqueous solution of the highest concentrations. However, we found that contributions of the larger oligomers to the absorption spectra are significantly large in the solution containing tetra-alkyl ammonium cation. We performed a transient absorption measurement for the solution of [Au(CN)2

−] containing the tetra-alkyl ammonium cations. In this case, a drastic rise in the transient absorption was also observed as in the case of trimer (Fig. 3). It was found that the time constant of the rise was much longer than that of trimer (~12 ps), suggesting that the bent to linear structural change in oligomers takes much longer in the case of larger oligomers.

Fig. 2. Femtosecond time-resolved absorption spectra of a K[Au(CN)2] aqueous solution in the time region of 0.1 – 10 ps. The arrow denotes modulation of the transient absorption peak. Inset shows the time-resolved absorption signal at 600 nm. (0.3 mol/dm3, λex = 310 nm)

FIG. 1. THE FRONTIER ORBITALS INVOLVED IN THE PHOTOEXCITATION OF [AU(CN)2−]2 AND [AU(CN)2−]3


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Observing the elementary chemical processes in complex molecular systems using ultrafast time-resolved spectroscopies is very important for understanding complicated chemical reactions. We believe the current result of structural change of oligomers of the gold(I) complex in solution provides a well-defined structural change within a complex molecular system, which can be a benchmark for recently advanced real-time simulations for structural change dynamics in solutions[5] as well as a good target of time-resolved X-ray techniques.[6] References [1]M. Iwamura, S. Takeuchi, T. Tahara, Accounts of Chemical Research 48 (2015)

782. [2]M. Iwamura, K. Nozaki, S. Takeuchi, T. Tahara, J. Am. Chem. Soc. 135 (2013)

538. [3]M.A. Rawashdeh-Omary, M.A. Omary, H.H. Patterson, J. Am. Chem. Soc. 122 (2000) 10371. [4]M.A. Rawashdeh-Omary, M.A. Omary, J.P. Fackler, Inorganica Chimica Acta 334 (2002) 376. [5]G. Cui, X.-Y. Cao, W.-H. Fang, M. Dolg, W. Thiel, Angewandte Chemie-International Edition 52 (2013) 10281. [6]K.H. Kim, J.G. Kim, S. Nozawa, T. Sato, K.Y. Oang, T.W. Kim, H. Ki, J. Jo, S. Park, C. Song, T. Sato, K. Ogawa, T. Togashi, K. Tono, M. Yabashi, T. Ishikawa, J. Kim, R. Ryoo, J. Kim, H. Ihee, S.-i. Adachi, Nature 518 (2015) 385.

Fig. 3. Femtosecond time-resolved absorption signal of a K[Au(CN)2] aqueous solution and that containing tetra-ethyl ammonium chloride (1.0 M) in the time region up to 30 ps. (0.3 mol/dm3, λex = 310 nm)


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Multiphoton Absorption Spectroscopy of Two-Dimensional Materials W. Q. CHEN1, F. ZHOU1 AND W. JI1

1Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551; e-mail: [email protected]

Recent advances in two-dimensional materials (2DMs), such as graphene and transition-metal dichalcogenides, have received tremendous attention because of their potential in nanophotonics and optoelectronics applications. The interaction between these 2DMs and femtosecond laser pulses is of relevance to both practical applications and fundamental physics. One of the examples is that the fundamental knowledge of saturation in interband transitions induced by one-photon absorption (1PA) in 2DMs can be utilized for mode-locking technology. Interestingly, apart from 1PA saturation, two-photon-induced interband transitions in graphene also have potential for photonic applications. In Ref. [1], coherent control and noncontact generation of ballistic photocurrents in multilayer epitaxial graphene at wavelengths of 3.2 µm / 1.6 µm and 4.8 µm / 2.4 µm have been demonstrated by utilizing the quantum interference between one-photon-induced and two-photon-induced interband transitions. Utilizing such noncontact method for generating electrical currents can overcome the difficulty of making reliable contacts for future graphene-based electronic devices, which have drawn intensive research interest due to the superior electron transport properties of graphene.

From the fundamental point of material properties, two-photon absorption (2PA) of graphene has not been systematically investigated in the visible spectral region. We have previously demonstrated, both theoretically and experimentally, that 2PA is as important as 1PA saturation in AB-stacking bilayer epitaxial graphene in the near infrared (NIR) spectral range [2]. Here, we present a systematical study on the interband 2PA of graphene in the visible spectrum (435-700 nm) with femtosecond laser pulses. By utilizing Z-scan technique and varying laser excitation wavelength, we are able to measure the 2PA spectrum ranging from 435 to 1100 nm. It reveals that 2PA is enhanced by the excitonic Fano resonance at the saddle point of graphene. Furthermore, based on the second-order, time-dependent perturbation theory, we develop a semi-empirical model in which interband transitions among three states near the saddle point of graphene are taken into consideration, together with interference between band-to-band transitions and excitons [3]. As shown in Fig. 1, we find that the model is in agreement with the photon-energy dependence of the observed 2PA spectrum with a scaling factor of B = (1~5) × 102 cm/MW/eV5.

In this talk, we also present the photo-electrical-current responses of monolayer molybdenum disulfide (1L-MoS2) when they are excited by processes of 2PA and three-photon absorption (3PA) in the spectrum from 800 nm to 1500 nm. Such multiphoton absorption spectroscopy reveals both 2PA and 3PA spectra in 1L-MoS2. The detailed theoretical model is still under development. A third-order perturbation quantum theory based on the excitonic energy diagram of 1L-MoS2 indicates that resonances with C-exciton and A- or B-exciton contribute to the observed 3PA. References [1] D. Sun, et. al., Nano Lett. 10, 1293-1296 (2010). [2] H. Z. Yang, X. B. Feng, Q. Wang, H. Huang, W. Chen, A. T. S. Wee and W. Ji,

Nano Lett. 11, 2622-2627 (2011). [3] W. Q. Chen, Y. Wang and W. Ji, published on-line by J. Phys. Chem. C (2015).

Fig. 1. Two-photon absorption (2PA) spectrum of monolayer graphene. The symbols are the experimental data and the solid curves are modelling.


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Driving charge and vibrational motions in strongly correlated organic conductors by nearly single-cycle 7fs, 10 MV/cm infrared strong field T. ISHIKAWA1, Y. NAITO1, Y. KAWAKAMI1, H. ITOH1, K. YAMAMOTO2, H. KISHIDA3, T. SASAKI4, M. DRESSEL5, Y. TANAKA6, K. YONEMITSU6 AND S. IWAI1* 1Department of Physics, Tohoku University, Sendai 980-8578, Japan 2Department of Applied Physics, Okayama Science University, Okayama 700-0005, Japan 3Department of Applied Physics, Nagoya University, Nagoya, 464-8603, Japan 4Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan 5Physikalisches Institut, Universität Stuttgart, 70569, Stuttgart, Germany 6Department of Physics, Chuo University, Tokyo 112-8551, Japan

Optical responses of organic conductors with electron correlations have attracted much attentions, because they

exhibit ultrafast solid-state phase transitions in the conducting and/or dielectric natures upon photo-excitations[1-5]. In this decade, photoinduced melting of electronic ordering have been extensively investigated, that is photoinduced insulator to metal (I-M) transition. On the other hand, recent development of several femtosecond laser in infrared region enables us to apply nearly single-cycle application of > MV/cm intense field. Such strong light field can realize non-perturbative electronic and/or vibrational responses which lead us to the highly-nonequilibrium electronic/vibronic states in solid materials [6]. Here, reverse process of the melting of charge ordering (I-M transition), i.e., the freezing of charge motion or the metal to insulator (M-I) transition has been discussed.

1) Photoinduced metal to insulator (M-I) transition was demonstrated by strong electric filed (10 MV/cm) of 1.5-cycle, 7 fs near infrared pulse in a layered organic conductor α-(ET)2I3. A large reflectivity change of > 25 % and a coherent charge oscillation in time axis reflecting the CO gap have shown that the generation of CO insulator state which survives 50 fs in the metallic phase. Such photoinduced metal to CO insulator change is attributable to the reduction of the inter-molecular transfer integral realized by high frequency strong electric field[7].

2) Intermolecular charge motion in quasi one-dimensional organic conductor (TMTTF)2AsF6 has been modulated with a strong light field of 9.8 MV/cm utilizing 1.5-cycle, 7 fs infrared pulse. Ultrafast snap-shot of reflectivity change of 40% showed that the plasma frequency (ωp) decrease 3 % in 20 fs (∼the timescale of intermolecular charge transfer before the electronic thermalization (∼100fs). A. 20 fs oscillation reflecting the coherent charge motion was also observed in the time profile of ωp. The theoretical consideration based on the extended Hubbard model clarified that the Coulomb repulsion plays an important role on the decrease of the electronic itinerancy. The reduction of ωp remains until 1.5 ps, that is stabilized by the molecular displacement perpendicular to the molecular stacking axis [8]. References [1] S. Iwai, K. Yamamoto et al., Phys. Rev. Lett. 98, 097402(2007). [2] Y. Kawakami, S. Iwai et al., Phys. Rev. Lett. 103, 066403 (2009). [3] Y. Kawakami, K. Yonemitsu, S. Iwai et al., Phys. Rev. Lett. 105, 246402(2010). [4] K. Itoh, Sasaki, Ishihara, Iwai et al., Phys. Rev. Lett. 110, 10640(2013). [5] H. Itoh, K. Itoh, Iwai et al., Appl. Phys. Lett. 104, 173302(2014). [6] H. Aoki, N. Tsuji, M. Eckstein, M. Kollar, T. Oka, P. Werner, Rev. Mod. Phys. 86, 780 (2014) [7] Ishikawa, Yonemitsu, Iwai et al., Nature Commun. 5, 5528(2014). [8] Y. Naitoh, M. Dressel, K. Yonemitsu S. Iwai, et al., submitted.

Fig. 1 (a) Schematic illustration of the optical "freezing" in α-(ET)2I3. (b) The ΔR/R spectrum reflecting the M-I transition in α-(ET)2I3 measured by a 7-fs pulse.

ACOVS11/ASC5 Book of Abstracts Session VI – Materials I

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SESSION VI – MATERIALS I


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Electroabsorption and Electrophotoluminescence Spectroscopies in Optoelectronic Materials N. OHTA

Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan [email protected]

Electroabsorption (E-A) spectroscopy, in which electric field-induced change in absorption spectrum is measured, is a powerful technique to investigate the electronic structure of each state as well as molecular orientation induced by applied electric field. Electric dipole moment (µ) both in the ground state and in the excited state can be determined, based on the measurements of the E-A spectra in solution. By applying this method to 4-N,N-dimethylamino-4’-N’-methyl-stilbazolium tosylate (DAST) microcrystal, which is one of the well-known organic nonlinear optical materials, the magnitude of µ of the DAST microcrystals has been determined to be as large as ~4.5 x 104 D in the ground state [1].

Electrophotoluminescence (E-PL) spectroscopy, where electric field-induced change in photoluminescence (PL) spectrum is measured, can be also used to determine the electric dipole moment of the emitting species. This method has been applied in solution to determine the magnitude of µ of the exciplex produced following the photoinduced electron transfer in some electron donor and acceptor systems.

When probed molecules are embedded in the solid matrix such as molecular crystals, polymers, or organic solvent glasses, embedded molecules are usually immobilized in the matrix, except for some molecules in a polymer film which somehow exhibit the field-induced orientation effect. The magnitude of the change in electric dipole moment and/or molecular polarizability following optical transitions can be determined by analyzing the E-A and E-PL spectra using the differential method, where E-A and E-PL spectra are reproduced by a combination of the zeroth, first and second deritatives of the absorption or PL spectra in solid films. In some cases, absorption bands which are not identified in the normal absorption spectrum because of the extremely weak intensity can be found from the E-A spectra, by using another analysis, i. e., the integral method analysis of the E-A spectra, where not only the zeroth, first and second derivatives but also the first and second integrals of the absorption spectrum are employed to analyze the E-A spectra. In fact, weak absorption bands located between the first and second strong exciton absorption bands which were not observed have been newly confirmed with the integral method analysis of the E-A spectra in PbSe and PbS quantum dots, which can be applied in optoelectronic devices because of the presence of the absorption spectra in the near infrared region [2].

Electronic structure, excited state dynamics and photoinduced function of materials are considered to be strongly related to each other. Therefore, there is no doubt that E-A and E-PL measurements have some impact on the well understanding of molecular photoexcitation dynamics and optoelectronic property especially in the case where electron-transfer plays an important role. Then, E-PL spectra of some porphyrin dyes which have been used as sensitizers in dye-sensitized solar cells (DSSC) have been measured. In the results, push-pull porphyrins which give high efficiency of DSSC show a significant electric field effect on fluorescence, that is, push-pull porphyrins which show high photovoltaic efficiency show a remarkable field-induced fluorescence quenching.

Thus, it is shown that E-A and E-PL measurements are applicable not only to examine the electronic structure of molecules and molecular systems but also to develop and design efficient optoelectronic materials [3]. References [1] H.-C. Chiang, T. Iimori, T. Onodera, H. Oikawa, N. Ohta, J. Phys. Chem. C 116 (2012), 8230-8235. [2] K. Awasthi, T. Iimori, N. Ohta, J. Phys. Chem. C 118 (2014), 18170-18176; 119 (2015), 4351-4361. [3] H.-Y. Hsu, H.-C. Chiang, J.-Y. Hu, K. Awasthi, C.-L. Mai, C.-Y. Yeh, N. Ohta, E. W.-G. Diau, J. Phys. Chem. C 117 (2013),

24761-24766.


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VUV Photoelectron Spectroscopy of Aqueous Aerosols: Implications in the Biological and Environmental Sciences C. C. WANG

Department of Chemistry,National Sun Yat-sen University, 70 Lien-Hai Rd., Kaohsiung, 80424, Taiwan, R.O.C. [email protected]

The crucial roles of aerosols have been increasingly recognized in a variety of important fields, encompassing the atmospheric chemistry, the environmental science and the planetary science. Recently, the implications of aerosols in the biomedical science, pharmaceutical administration and micro-fabrications of nano-structured materials have also been actively explored. To probe the valence electronic structure of aerosols, which decisively determines their chemical activities, an aerosol VUV photoelectron spectroscopy apparatus has been recently built1, using the synchrotron-based VUV radiation as the photoionization source. Preliminary efforts have been focused on studying aqueous aerosols. By introducing the samples of interest into the aerosol phase and collimating them into a focused nanoparticle beam, this novel aerosol apparatus readily creates a microscopic aqueous environment, allowing one to interrogate the hydrated structure of biologically important materials and extract information that can only be accessed under queous conditions, such as the solvent effect, pH effect and the solvent-solute interaction.

Recently, we apply the aerosol VUV photoelectron spectroscopy apparatus to investigate the valence electronic structure of several biologically important amino acids and small peptides, including cysteine and glutathione aqueous aerosols for the first time. The photoelectron spectra of Cys aqueous aerosols show distinct band shapes at varying pH conditions, reflecting the altered molecular orbital characters when its dominating form changes [1]. The ionization energy of Cys is determined to be 8.98 ± 0.05 eV at low pH. A new feature at a binding energy of 6.97 ± 0.05 eV is observed at high pH, suggesting that the negative charge on the thiolate group becomes the first electron to be removed upon ionization. This set of work provides a microscopic view of nucleophilicity and its evolution with changing pH conditions. On the other hand, the valence electronic structures of the thiol-containing tripeptide, glutathione have also been investigated for the first time, from which new insight underlying its biological significance has been discussed.

The newly developed aerosol VUV photoelectron spectroscopy technique not only exhibits the capability to probe the solvated species, but also sheds new light for one to investigate the electronic structure of aerosols and complex molecular assemblies in a size-selective and composition-controlled way. With this new aerosol investigation tool, it is promising to address numerous fundamental but critical issues regarding aerosols in their related fields, including the environmental science, the atmospheric chemistry and the biomedical science. References [1] C. Su, Y. Yu, P. Chang, Y. Chen, I. Chen, Y. Lee, C. C. Wang, J. Phys. Chem. Lett. 6 (2015), 817–823.


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Using resonant Raman scattering from excitonic states to determine orientation of electronic transition dipoles M. R. WATERLAND

Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand, [email protected] Resonance Raman scattering provides a wealth of information on the excited electronic states of molecules and materials. It is particularly useful when scattering is observed simultaneously from two (or more) resonant electronic states. Due to the indeterminacy of the virtual scattering state, scattering amplitudes from each state interfere, leading to variations in scattering intensity as a function of excitation wavelength. The strength of the interference is determined, in part, by the angle between the transition dipole moments of the resonant electronic states. Analysis of resonance Raman intensities provides a measurement of this parameter (along with a host of other parameters).

In this work use resonance Raman spectroscopy and computational chemistry to determine the nature of excitonic states in a metalloazadipyrrin compound, Cu(L-aza)2 (structure shown above). The variations in scattering intensity are clearly shown in the resonant Raman excitation profiles. The experimental data points along with the simulated intensities are shown (middle figure). Optimum fits of the simulated intensities are obtained when the angle between the transition dipole moment matches the angle calculated using unrestricted time-dependent density functional theory calculations (right figure). Exciton coupling theory provides a simple description of the electronic excited states of systems with strongly coupled electronic excited states. Azadipyrrins have strongly allowed transitions that couple strongly when bound by a central metal atom as in the Cu(L-aza)2 system. However, previous applications of exciton theory to the Cu(L-aza)2 failed to produce the required electronic structure, based upon the assumption of the transition dipoles lying in the plane of the dipyrromethane unit, as is widely observed in the well-known dipyrrin family of compounds. Our computational studies suggested that the transition dipoles were directed towards the phenyl substituents, and were, in fact, co-planar. The transition dipole angle obtained independently via simulation of the resonance Raman intensities agrees closely with the calculated result. The same model that describes the Raman intensities is also used to simulate the absorption band profile and close agreement with the absorption profile provides further confidence that our results correctly describe the exciton structure in azadipyrrin systems Acknowledgement Financial support from Massey University and the MacDiarmid Institute for Advanced Materials and Nanotechnology is gratefully acknowledged. References [1] Waterland, M. R., et al. Molecular Excitons in a Copper Azadipyrrin complex Dalton Transactions 2014, 43, 17746


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In Situ Particle Film ATR FTIR Spectroscopy of poly (N-isopropyl acrylamide) Adsorption on Talc D. A. BEATTIE1, J. ADDAI-MENSAH1, A. BEAUSSART1, G. V. FRANKS2 AND K.-Y. YEAP1

1Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095, Australia, [email protected] 2Chemical and Biomolecular Engineering, University of Melbourne, Parkville, VIC 3010, Australia

The adsorption of poly (N-isopropyl acrylamide) (PNIPAM) onto talc from aqueous solutions has been studied using the in situ methodology of particle film attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy [1]. PNIPAM was observed to adsorb significantly onto the talc particle film at a temperature below its lower critical solution temperature (LCST). Peak shifts were seen in the adsorbed layer FTIR spectrum that match those observed when PNIPAM solution is heated above its LCST. This observation indicates that adsorption causes a conformational re-arrangement similar to that seen when PNIPAM undergoes a coil-to-globule transition, in this case presumably induced by hydrophobic interactions between PNIPAM and the talc basal plane surface. The kinetics of adsorption are seen to be complex, with potential influences of conformational rearrangement and differential adsorption kinetics for the two dominant surface regions of talc particles. The adsorbed PNIPAM was seen to be exceptionally resistant to removal, with no desorption occurring when a background electrolyte solution was flowed over the adsorbed layer. Spectra acquired of the adsorbed polymer layer heated above the LCST reveal that a further conformational rearrangement takes place for the adsorbed layer, finalizing the transition from coil-to-globule that was initiated by the interaction with the mineral surface. Acknowledgement DAB acknowledges the financial support from the Australian Research Council Future Fellowship scheme (FT100100393), and the Discovery Project scheme (DP110104179). The authors thank John-Paul O’Shea for synthesizing the PNIPAM. References [1] D.A. Beattie et al, PCCP, 16 (2014), 25143–25151.

ACOVS11/ASC5 Book of Abstracts Session VII – Biospectroscopy II: Cells and Bacteria

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SESSION VII – BIOSPECTROSCOPY II: Cells and Bacteria


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Factors Influencing Bacterial Identification by Raman Spectroscopy M. M. HLAING1, M. DUNN1, S. L. MCARTHUR1 AND P. R. STODDART1

1Faculty of Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, Australia [email protected]

Microbial biofilms can cause serious problems in a range of medical situations (e.g. implant infections) and industrial contexts (e.g. microbiologically-influenced corrosion). Consequently there is an urgent need for rapid, in situ identification of bacteria in biofilms, in order to facilitate diagnosis and treatment. Raman spectroscopy has received a good deal of attention as a non-destructive method for identifying single bacteria at species and strain level, and for studying different bacterial growth phases [ref]. The Raman spectrum reflects the overall molecular composition of an individual organism, with identification based on features that can be associated with specific organisms. However, these studies have been performed under controlled laboratory conditions with bacterial cells taken from planktonic suspensions or recovered from biofilm, including pseudo-mixed biofilms and single species biofilms. These experimental conditions may not accurately reflect the complexity of real world settings, where a biofilm might contain bacteria from different points in their life cycle, and bacteria may exhibit varying responses to the presence of other organisms in the consortium, or to different physicochemical environmental conditions. All of these factors can contribute to differences in macromolecular composition and metabolic heterogeneity.

Here we report on the implications of these various factors for extending Raman spectroscopic identification to more realistic sampling conditions. Experiments were performed on (i) planktonic bacteria at different growth time points, (ii) bacteria from intact colonies and biofilm (including a dual species biofilm), and (iii) surface-attached bacteria exposed to different surface chemistries. In keeping with many previous studies, the experiments were performed with 514 nm excitation on low-fluorescence substrates such as quartz or CaF2. A penalised least-squares fitting algorithm was used with an enhanced adaptive weighting scheme to automatically remove the autofluorescence background from the spectra [ref]. The effects of different sample storage and preparation methods were also considered in order to minimise sample-to-sample variations during the study. Interestingly, the results of this optimization study highlighted the role of bacterial extracellular polymeric substances in the cellular response to environmental stresses [ref].

For the planktonic bacteria, Raman spectroscopy was combined with chemometric analysis to discriminate between four different bacterial species (Escherichia coli, Vibrio vulnificus, Pseudomonas aeruginosa, Staphylococcus aureus) at different stages of their life cycle. The results showed that bacterial cells from a particular growth time point could be reliably identified using principal component analysis (PCA), while bacteria from different growth phases could be classified with a prediction model based on principal components and linear discriminant analysis (PC-LDA). The successful implementation of these techniques served to confirm previously reported results and provided a point of comparison for our subsequent studies performed under progressively more realistic conditions.

In the next experiments, Raman spectra were obtained from surface-attached cells in intact bacterial colonies and biofilms of the four species grown on quartz substrates. The results showed a significant increase in the carbohydrate, protein and nucleic acid content of the biofilm matrix during the biofilm growth. While these findings suggest that Raman spectroscopy has significant potential for studying chemical variations in bacteria during biofilm formation, relatively poor results were obtained for the classification of the surface-attached biofilm cells, using the planktonic PC-LDA model. Given that cells within a biofilm experience a different mode of growth to their planktonic counterparts, this is perhaps not a surprising result. Indeed, when a new PC-LDA model was calibrated using single spectra from biofilm cells of each species and validated with pure E. coli biofilms, a high accuracy of classification was obtained. This new model also achieved 75% sensitivity in identifying the presence of E. coli and V. vulnificus in a dual-species biofilm.

This prediction accuracy may be useful for studying species interactions and for analysing biofilm formation in more complex communities. However, it implies that a new classification model may be required to identify the same bacterial species in each different type of biofilm. To explore this issue in more detail, different plasma polymer thin films with hydrocarbon, amine and carboxyl groups were used to study surface-attached E. coli cells. In situ identification of the cells was hindered by weak spectral features due to the polymer background. This issue was overcome by removing the cells from the polymer coated substrate and smearing them onto clean CaF2 slides, whereupon the bacteria could be accurately classified using the PC-LDA planktonic model, as shown in Fig. 1. However, detailed analysis of specific peaks showed that the spectral profiles of the surface-attached cells were subtly different from the planktonic cells, due to their interaction with the different surfaces. This suggests that future studies should evaluate phenotypic variability between species and identify the diversity of macromolecular composition throughout biofilm development under different environmental conditions.

Fig. 1. Classification of surface-attached E. coli cells transferred from plasma polymer-coated surfaces to a CaF2 substrate (test samples). The scatter plot shows reasonably good agreement with a model based on the planktonic cell training set.


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The results obtained in this study are encouraging for studying chemical variations during biofilm formation under controlled conditions. It is also encouraging that accurate classification results can be obtained when surface-attached cells are transferred to a low-background substrate, as this approach could in principle be applied to the identification of bacteria recovered from biofilm. However, significant challenges remain in applying Raman spectroscopy to bacterial identification in real world settings. Further studies are required to validate the PC-LDA planktonic model with more bacterial species. Environmental factors such as temperature, pH and nutrient composition should also be taken into account for future studies of factors influencing bacterial identification. Moreover, it should be noted that the time taken to collect high quality Raman spectra from bacteria remains a limiting factor in terms of collecting a sufficiently large number of spectra for more reliable PCA training sets. Acknowledgement The authors gratefully acknowledge the support of the L.E.W. Carty Charitable Fund for this research. M.M.H. thanks the Defence Materials Technology Centre for scholarship support. References [1] A. Harz, P. Roesch, J. Popp, Cytometry 75A(2) (2009), 104-113. [2] P. J. Cadusch, M. M. Hlaing, S. A. Wade, S. L. McArthur, P. R. Stoddart, J. Raman Spectrosc. 44 (11) (2013), 1587-1595. [3] M. M. Hlaing, J. M. Dunn, S. L. McArthur, P. R. Stoddart, Int. J. Integrative Biology 15(1) (2014), 11-17.


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Automatic and Objective Cell Discrimination by Raman Spectroscopy with Multivariate Curve Resolution Analysis M. ANDO1 AND H. HAMAGUCHI1,2

1Research Organization for Nano & Life Innovation, Waseda University, 513 Wasedatsurumaki-cho, Shinjuku, Tokyo, 162-0041 Japan [email protected] 2Institute of Molecular Science and Department of Applied Chemistry, National Chiao Tung University, 1001 Ta Hsuch Road, Hsinchu 300, Taiwan

Raman spectroscopy is now well established as a unique spectroscopic tool for fundamental biomedical research. It is yet to be established, however, as a general biomedical tool for everyone’s use. Development of automatic and objective Raman spectroscopy, which is readily employed by non-specialist to extract biomedical information in a straightforward manner, is longed for. In the present talk, we will discuss the possibility of using the multivariate curve resolution-alternating least squares (MCR-ALS) analysis for automatic and objective in vivo living cell discrimination by Raman spectroscopy.

We apply the MCR-ALS analysis to a total of 10400 Raman spectra (400 Raman spectra from 26 different leukocyte; 12 neutrophils, 5 eosinophils, 6 lymphocytes, and 3 monocytes) to obtain eight chemically interpretable spectra S-1 to S-8 and their spatial distributions (Figure 1).

Figure 1. MCR-ALS retrieved spectral components (A) and distribution images (B) for (a) neutrophils, (b) eosinophils, (c) lymphocytes, and (d) monocytes.

S-1 is ascribed to nucleus (nucleic acids + proteins), S-2 myeloperoxidase (MPO), S-3 eosinophil peroxidase (EPO),

S-4 lipids, S-5 carotenoids, S-6 proteins in cytoplasm, S-7 proteins + MPO and S-8 water. The plot of the contributions of S-2, S-3 and S7 relative to S-6 is shown in Figure 2.The four different types of white blood cell are clearly discriminated. Now that we have established the principal MCR spectral components in white blood cells, any new sample can be analysed automatically and objectively for fast in vivo discrimination.

Figure 2. Contribution scatter plot of MCR-ALS retrieved component 2, 3, and 7 for the discrimination of four types of leukocytes: neutrophils (red), eosinophils (pink), lymphocytes (brown), monocytes (green).


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Quantitative approaches to surface-enhanced Raman measurements inside a cell N. I. SMITH

Biophotonics Laboratory, Immunology Frontier Research Center, Osaka University, 565-0871, Japan. e-mail:[email protected]

The very large boost in Raman scattering that can occur at a plasmonic structure offers the possibility of extremely sensitive vibrational spectroscopy. Research into the optimization of interface-based techniques, such as a plasmonic substrate, is resulting in highly efficient measurements of samples that can be dropped on the substrate and readily measured. However, many of the most exciting developments in plasmonics for surface-enhanced Raman scattering (SERS) are not suitable for use inside biological cells. The fundamental problem is that the enhancement usually occurs in the local vicinity of a nanoparticle or in the hot spots between nanoparticle aggregates. Nanoparticles can be added to living cells, particularly macrophage cells, where they can then report the local molecular environment [1], but there are very limited methods available to control the location or to target particular regions in the cell. When particles travel through the cell, they encounter various molecules involved in the cellular uptake and transport pathways, and this can be exploited by simultaneously measuring both the particle position and SERS spectra from the particle [2]. The resulting spatiotemporal map gives some clear molecular contrast to different parts of a particle trajectory in the cell.

Even with the inherent SERS fluctuations and lack of information regarding the intracellular transport pathways and constituent molecules, this combined approach is a promising approach to quantifying SERS spectral measurements inside cells. It is difficult to directly link the measured SERS spectra with specific intracellular molecules, but tendencies can be observed. For example, the spectra measured during the early part of uptake can include peaks that can be assigned to molecules or proteins thought to be involved in the uptake and transport, whereas later appearing spectra can show tendencies towards phosphate groups which could indicate lysosome formation or other later stages of particle uptake [1]. It is possible to track a single particle and look at temporal variations in the spectra as it moves through the cell [2], or alternatively use an algorithmic approach to classify all spectra from nanoparticles in a group of cells under SERS imaging [3]. The final destinations and the reported SERS spectra can also be varied to some degree depending on the particle coating or surface charge and other parameters [4].

As an alternative, however, since we cannot generally control the location of dynamics of the nanoparticles which enter the cell through normal biological processes, it would be of significant advantage to have the ability to create the nanoparticles directly inside the cell. This would alleviate the problem of not knowing whether nanoparticles enter the cell or where they move to after entering. Direct fabrication of gold nanoparticles inside the cell interior was found to be possible by first infusing a precursor gold ion solution through the cell, followed by irradiation of 532 nm cw laser beam, focused at a targeted location in the cell [5]. Following irradiation, the extraneous ion solution was washed out by saline solution and the photofabricated nanoparticles remained in place at the laser focal region. Following fabrication, further irradiation by a near infrared laser beam at 780 nm was found to excite plasmon resonance in the nanoparticles without the interference of luminescence from the gold material. Enhanced Raman spectra were then measured from the photofabricated regions. SERS signals are usually observed from nanoparticles or aggregates of nanoparticles on the order of 50 nm in diameter. By TEM analysis, the fabricated particle diameters were found to be only several nanometers in diameter making the subsequent measurement of SERS surprising. The successful generation of SERS from such small intracellular targets is presumably due to aggregation of the formed nanoparticles.

The observed SERS spectra show that the process can be used to fabricate intracellular plasmonic Raman probes at any location inside the cell. The ability to target any location in the cell, including those where nanoparticles could not typically enter such as inside organelles or in the nucleus, allows the expansion of SERS measurements to a more targeted approach. Perhaps surprisingly, even when the laser focus can be positioned at will inside the cell to control particle formation, SERS spectra are not detected from all fabricated nanoparticle locations, and there remain interesting questions regarding why some nanoparticle regions produce more SERS than others. The algorithmic approach mentioned above [3], which uses a non-biased method of evaluating and classifying spectra is still a useful tool even when the physical locations of the intracellular nanoparticles are under our control.

References [1] K Fujita, S Ishitobi, K Hamada, NI Smith, A Taguchi, Y Inouye, S Kawata, J. Biomed. Opt. 14 (2), 024038-024038-7 (2009). [2] J. Ando, K. Fujita, N. Smith and S. Kawata, Nano Lett. 11(12), pp. 5344-5348 (2011). [3] N. Pavillon, K. Bando, K. Fujita and N. I. Smith, "Feature-based recognition of Surface-enhanced Raman spectra for biological targets", J. Biophotonics 6(8), pp. 587-597 (2013). [4] D. Pissuwan, A. J. Hobro, N. Pavillon and N. I. Smith, "Distribution of label free cationic polymer-coated gold nanorods in live macrophage cells reveals formation groups of intracellular SERS signals of probe nanoparticles", RSC Advances 4(11), pp. 5536-5541 (2014). [5] N. I. Smith, K. Mochizuki, H. Niioka, S. Ichikawa, N. Pavillon, A. J. Hobro, J. Ando, K. Fujita and Y. Kumagai, "Laser-targeted photofabrication of gold nanoparticles inside cells", Nat. Commun. 5(5144), pp. 1-9 (2014).


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Vibrational Spectroscopy of Southern Ocean Phytoplankton: a new approach for understanding drivers of primary productivity P. HERAUD1,2, O. SACKETT1,2, K. PETROU3, J. BEARDALL2 1Centre for Biopectroscopy, School of Chemistry, Monash University, Wellington Road, Clayton, 3800, Victoria, Australia. [email protected] 2School of Biological Sciences, Monash University, Wellington Road, Clayton, 3800, Australia. 3Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, 15 Broadway, Ultimo, 2007, New South Wales, Australia.

Each year, marine phytoplankton (unicellular microalgae) convert ~50 Tg of inorganic carbon into the building blocks of life - proteins, lipids and carbohydrates, which comprise ~95% of organic matter. This massive quantity of organic carbon, which is approximately equal in magnitude to carbon assimilation by all the terrestrial rainforests on earth, provides nutrition and energy to marine food webs and is known as primary production. As well as supporting marine fisheries worth an estimated 75 billion US$ annually, primary production is an important component of the global carbon cycle. Hence, substantial scientific effort is devoted to its measurement. At present estimations of oceanic primary productivity are quite crude limited to biomass determination using a combination of satellite chlorophyll fluorescence imaging and ground based turbidity measurements. These current measurements lack definition in terms of quantifying species composition within the phytoplankton blooms nor do they define the physiological status of the different species and how this is affecting carbon uptake and partitioning of carbon within cells. Infrared spectroscopy is a powerful new tool in this area of research having potential for both species identification and characterisation of physiological responses of living phytoplankton to the environment in terms of carbon partitioning at the single cell level [1]. A significant breakthrough in this context is the modelling of infrared spectroscopy against 13C uptake in cells to create the ability to perform "snapshot" predictions of primary productivity based on single infrared measurements [2].

Iron limitation is known to affect the primary productivity of phytoplankton in the otherwise nutrient rich Southern Ocean [3]. Enhanced supply of nutrient-rich waters along the coast of the subantarctic Kerguelen Island provided a valuable opportunity to examine the responses of phytoplankton to natural Fe enrichment. Synchrotron radiation Fourier Transform Infrared (SR-FTIR) microspectroscopy was used to analyse changes in the macromolecular composition of diatoms collected along the coast and plateau of Kerguelen Island. SR-FTIR microspectroscopy enabled the analysis of individual diatom cells from mixed communities of field-collected samples, thereby providing insight into in situ taxon specific responses in relation to changes in Fe availability. Phenotypic responses were taxon-specific in terms of intraspecific variability and changes in proteins, amino acids, phosphorylated molecules, silicate and carbohydrates. The highly abundant taxon Fragilariopsis kerguelensis displayed a higher level of phenotypic plasticity than Pseudo-nitzschia spp., while analysis of the data pooled across all measured taxa showed different patterns in macromolecular composition compared to those for individual taxon. This study demonstrated that taxon-specific responses to Fe enrichment may not always be accurately reflected by bulk community measurements, highlighting the utility of the biospectroscopic approach compared with traditional analytical approaches. References [1] Sackett O, Petrou K., Reedy B., De Grazia A., Hill R., Doblin M., Beardall J., Ralph P.,Heraud P. (2013), Plos One, 8(11), 1-12. [2] Sackett O., Petrou K., Reedy B., Hill R., Doblin M., Beardall J., Ralph P., Heraud P. (2015) ISME Journal (accepted June 2015) [3] Sackett O., Armand L., Beardall J., Hill R., Doblin M., Connelly C., Howes J., Stuart B., Ralph P., Heraud P. (2014),

Biogeosciences, 11, 5795-5808.


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Visualizing Fungal Cell Wall Architecture by Confocal Raman Microscopy H. NOOTHALAPATI1, M. KAWAMUKAI2 AND T. YAMAMOTO1,2

1Raman Project Center for Medical and Biological Applications, Shimane University, Matsue, 690-8504, Shimane, Japan [email protected] 2Department of Life and Environmental Science, Shimane University, Matsue, 690-8504, Shimane, Japan

Cell wall is a tough yet flexible structure that confers shape and protection to the cell. Fungal cell wall is a dynamic

organelle that plays a vital role, particularly in cellular growth, elongation and division. Any modification or disruption of the wall leads to lysis and cell death, hence serving an excellent target for anti-fungal drugs. Fungal cell walls are unique in that it differs greatly from well studied cellulose based plant cell walls. Chemically, the cell wall architecture in fungi is complex comprising mainly polysaccharides (glucan, mannan and chitin) and a small proportion of glycoproteins. Traditionally, electron microscopy and biochemical extraction methods were employed while recently immunocytochemical analysis is used to understand its structure. The former lacks chemical specificity requiring genetically modified cells to study different structures in detail while the later involves development of fluorescent monoclonal antibodies specific to glycosidic linkages among cell wall polysaccharides. Moreover, all these methods involve tedious procedures. Hence we aim to develop a label-free method based on confocal Raman microscopy, which is both simple and robust, to visualize distribution of various polysaccharide components of fungal cell wall. Fission yeast Schizosaccharomyces pombe is used as a model to demonstrate our method. Outer layer of fission yeast cell wall is made of galactomannan while glucan component (predominantly α-1,3-glucan and β-1,3-glucan with occasional β-1,6-glucan branches) forms the wall core. Raman spectrum, otherwise called a molecular fingerprint, enables us to get detailed molecular information from subcellular locations without requiring any fluorescent labels. As a first step, space-resolved Raman spectra from lipid droplets, cytoplasm and cell wall were obtained to identify marker bands for individual components (Fig. 1A). We distinguished α- and β-glucans using anomeric vibrational bands in a straightforward manner. Then, by employing nonnegative matrix factorization (NMF) method, we successfully separated Raman spectra of several pure bio-macromolecular components (glucans and mannan along with proteins and lipids etc..) whose detailed chemical images are shown in Fig. 1B. We believe that our method will be help in understanding the structure and dynamic re-organisation of fungal cell walls. In this regard, we further extended our method to investigate yeast spore walls and the results will be discussed in the meeting.

References [1] Jean-Paul Latge, Molecular Microbiology, 66, 279-290 (2007). [2] Shaun M. Bowman and Stephen J. Free, BioEssays, 28, 799-808 (2006).

Fig. 1. (A) Space resolved Raman spectra obtained from lipid droplet (lipid), cytoplasm (protein) and cell wall. (B) Chemical images of protein, glucan, mannan, polyphosphate (polyP) and ergoserol (lipid) after NMF analysis along with their optical image.


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Spectroscopic Study of Light-Driven Sodium-Pumping Rhodopsin H. KANDORI Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan [email protected]

Light-driven H+ pump bacteriorhodopsin (BR) and Cl- pump halorhodopsin (HR) were discovered from Halophilic archaea 35-40 years ago. Light-driven pumps are used to create membrane potential for ATP-synthesis, and their pump mechanisms have been extensively studied [1-4]. Since 2000, genomic analysis identified >5,000 microbial rhodopsins from marine bacteria, most of which were classified into light-driven H+ pump (proteorhodopsin).

HR can pump not only Cl-, but also other monovalent cations such as Br-, I- and NO3-

. On the other hand, microbial rhodopsins can pump only H+, no other cations. It may be reasonable because the chromophore (protonated Schiff base of all-trans retinal) is positively charged, so that cations cannot stay in the Schiff base region except for the covalently attached H+. However, we recently discovered light-driven outward Na+ pump from marine bacteria [5]. The Na+-pumping rhodopsin, Krokinobacter Rhodopsin 2 (KR2), can also pump Li+, but it becomes a H+ pump in KCl and with salts of larger cations. Therefore, KR2 is a compatible Na+-H+ pump. KR2 has identical absorption spectra with and without Na+, indicating that the Na+-biding site is distant from the retinal Schiff base region, and we identified the binding site at the extracellular domain using ATR-FTIR spectroscopy [5].

We further studies molecular mechanism of KR2 using various spectroscopic techniques [6-9], which will be presented in my talk. References [1] O. P. Ernst, D. T. Ludowski, M. Elstner, P. Hegemann, L. S. Brown, H. Kandori, Chem. Rev. 114 (2014), 126-163. [2] K. Inoue, Y. Kato, H. Kandori, Trends Microbiol. 23, 91-98 (2015) [3] H. Kandori, In Chemical Science of π-Electron Systems, T. Akasaka, A. Ohtsuka, S. Fukuzumi, Y. Aso, H. Kandori (Eds.), Elsevier (2015), in press. [4] H. Kandori, In Optogenetics, H. Yawo, H. Kandori, A. Koizumi (Eds.), Elsevier (2015), in press. [5] K. Inoue, H. Ono, R. Abe-Yoshizumi, S. Yoshizawa, H. Ito, K. Kogure, H. Kandori, Nat. Commun. 4 (2013), 1678. [6] H. Ono, K. Inoue, Abe-Yoshizumi, H. Kandori, J. Phys. Chem. B 118 (2014), 4784-4792. [7] K. Inoue, H. Ono, H. Kandori, Chem. Lett. 44 (2015), 294-296. [8] H. E. Kato, K. Inoue, R. Abe-Yoshizumi, Y. Kato, H. Ono, M. Konno, T. Ishizuka, M. R. Hoque, S. Hososhima, H. Kunitomo, J. Ito, S. Yoshizawa, K. Yamashita, M. Takemoto, T. Nishizawa, R. Taniguchi, K. Kogure, A. D. Maturana, Y. Iino, H. Yawo, R. Ishitani, H. Kandori, O. Nureki, Nature 521 (2015), 48-53. [9] K. Inoue, M. Konno, R. Abe-Yoshizumi, H. Kandori, Angew. Chem. Int. Ed. (2015), in press.

ACOVS11/ASC5 Book of Abstracts Session VIII – Fundamentals

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SESSION VIII – FUNDAMENTAL


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CH•••O Hydrogen bond mediated microsolvation of imidazole derivatives S. WATEGAONKAR1 AND A. BHATTACHERJEE1,2

1Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, 400005, India; E-mail: [email protected] 2Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA

Although branded as weak hydrogen bonding players, there is ample evidence in the recent times that the non-covalent interactions involving the lesser electronegative atoms such as carbon and sulfur atoms can be described as hydrogen bonding interactions. Most of the evidence for such interactions has been the distance and angle constraints derived from the protein data bank or the Cambridge structural database. Spectroscopic evidence on such interactions has been very scarce in the literature.

The CH•••O interaction specifically has been implicated as playing an important role in the enzymatic activity in serine hydrolases as well as in strengthening the beta sheet structures in many proteins. For instance, the C2H group of the imidazole moiety of the histidine has been proposed1,2 to interact with the carbonyl group of the backbone and thus facilitate the proton transfer in serine hydrolases. In this talk, I will present the results from our work involving a multifunctional imidazole derivative, namely, benzimidazole that has a weakly activated CH donor, besides a nitrogen atom as H-bond acceptor as well as the N-H donor. It also has pi electron density as an acceptor of H-bond. I shall discuss the microhydrated structures (up to four water molecules) of benzimidazole and its N-methylated analog, N-methylbenzimidazole (NBIM). Solvated complexes of these two molecules were formed in supersonic jet expansion and probed by UV and IR spectroscopic techniques. Quantum chemical calculations carried out at the DFT and MP2 levels are in line with the experimental findings. Although the first water molecule binds to the conventional sites, namely NH and N atom, the second and the rest water molecule bind to the molecule through a CH•••O interaction. We provide an unequivocal evidence of this interaction. It was concluded that the CH group in BIM was not sufficiently activated to attract the first water molecule, however after the first water molecule binds to the substrate it becomes a potent H-bond donor. The role of the unconventional hydrogen bond donor, C-H, in stabilizing the microhydrated structures of NBIM was apparent although the NH site was blocked by N-methylation. This is also in line with the observation that NBIM is more soluble in water than benzimidazole itself. Acknowledgement This work was funded by the Tata Institute of Fundamental Research, Mumbai, INDIA. References [1] Z.S. Derewenda, U. Derewenda, P.M Kobos, J.Mol. Biol. 241 (1994), 83-93. [2] E.L. Ash, J.L. Sudmeier, R.M. Day, M. Vincent, E.V. Torchilin, K.C. Haddad, E.M. Bradshaw, D.G. Sanford, W.W.

Bachovchin, PNAS 97 (2000), 10371-10376.


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Structural evolution of the retinal chromophore in the photocycle of microbial ion pumps M. MIZUNO1, A. NAMAJIMA1, H. KANDORI2 AND Y. MIZUTANI1

1Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan. 2Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan. e-mail. [email protected]

One of the most characteristic functions of microbial rhodopsins is a light-driven ion pump across cell membrane. Microbial rhodopsins contain all-trans-retinal as a chromophore, which is covalently bound to a lysine residue through a protonated Schiff base (PSB) linkage. Absorption of a photon induces the chromophore isomerization and leads to a cyclic reaction. To reveal mechanism in ion pumping, it is essential to elucidate sequential changes in the chromophore structure in a photocycle. So far, however, less information on the evolution of structural changes has been reported except for the photocycle of bacteriorhodopsin (BR). Time-resolved resonance Raman (TR3) spectroscopy enables us to examine the evolution of the structural changes of the retinal chromophore. In this study, we measured TR3 spectra of two microbial rhodopsins, halorhodopsin from Natronobacterium pharaonis (pHR) as a chloride ion pump and Gloeobacter rhodopsin (GR) as a proton pump, in the time range from nanoseconds to milliseconds.

Based on the observed TR3 spectra, we successfully identified resonance Raman spectra of the retinal chromophore in every steps of the photocycle for both proteins. Although spectral features of the intermediates were basically similar to those of BR [1], some differences were found in their structures and kinetics among the proteins. We observed some structural markers, such as due to the hydrogen out-of-plane (HOOP) wags, the ethylenic (C- C and C=C) stretch, and the C=NH+ stretch modes. According to changes in the structural markers, we discussed how the protein structure evolves to pump ions across the membrane.

1. Halorhodopsin

Fig. 1a shows TR3 spectra of pHR probed at 475 nm. The sample was a chloride binding form solubilized with a detergent. The probe wavelength was resonant with the electronic transitions both due to the unphotolyzed state (HR) and early photointermediates [2]. Three intermediates were observed in the TR3 spectra. For the strongest band appearing around 1520–1560 cm−1, which is assigned to the C=C stretch, the band at 1526 cm−1 was observed in HR. After photoexcitation, the band at 1533 cm−1 was observed from 50 to 300 ns. From 100 ns, the strong band at 1550 cm−1 increased up to 1 µs, and did not change from 1 to 10 µs. After 100 µs, a shoulder around 1558 cm−1 appeared. The C=C stretching frequency is correlated with the absorption maximum wavelength. The bands at 1533, 1550, and 1558 cm−1 were due to the K, L, and N intermediates, respectively. In milliseconds, the bands due to both the L and N intermediates seemed to decay with the same rate, indicating that the equilibrium between L and N is achieved until 1 ms.

Fig. 1b shows resonance Raman spectra in HR, K, L, and N. The moderately strong C–C stretch band appeared at 1204 cm−1 in HR. This band diminished in photointermediate, and instead, a new band appeared at 1198 cm−1 in K, and shifted to 1188 and 1185 cm−1 in L and N, respectively. The C–C stretch band is a marker for the retinal configuration. In the intermediates, their spectra showed the chromophore is in the 13-cis form. The HOOP band was observed at 973 cm−1 only in K. Appearance of the HOOP band indicates distorted polyene chain in retinal. The spectra suggest that the chromophore in K is distorted and that in L and N is relaxed to be a planar geometry.

The C=NH+ stretch is a coupled mode between the C=N stretch and N- H bend. Its frequency is sensitive to the hydrogen-bond strength in PSB, which is involved in the pathway of ion translocation. The frequency at 1634 cm−1 in HR downshifted to 1621 cm−1 in K, upshifted to 1650 cm−1 in L, and slightly downshifted to 1647 cm−1 in N. When exchanging H2O against D2O as a solvent, a Schiff base proton can be completely replaced to a deuteron. Deuteration effects on the resonance Raman spectra were also measured. In HR, the band at 1634 cm−1 in H2O downshifted to 1624 cm−1 in D2O. In the intermediates, the frequencies were 1612, 1621, and 1622 cm−1 in the K, L, and N intermediates, respectively. It is well known that PSB with stronger hydrogen bond exhibited higher C=NH+ stretching frequency and larger deuteration shift [3]. The spectral changes in the C=NH+ mode indicate that the hydrogen bond in PSB is weakened upon K

Fig. 1. (a) TR3 spectra of pHR probed at 475 nm. The top black trace is the probe-only spectrum. The other grey spectra are time-resolved difference spectra. (b) Resonance Raman spectra in HR, K, L and N. The asterisk is the band due to the intensity standard.


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formation and is strengthened in the K-to-L transition. Previous FTIR study proposed that the proton acceptor in PSB is replaced in the step of L formation [4]. It was found that the hydrogen bond in PSB was weakened upon retinal photoisomerization prior to replacement of the hydrogen bond. In addition, we observed upshift only for the C=NH+ stretch band in early stage of L, which seemed to be due to changes in interaction between PSB and protein moiety. Our observations imply that replacement of a proton acceptor in SB makes the newly formed hydrogen bond in SB strong, accompanying the structural relaxation of protein moiety. These protein motions promote the initial translocation of the chloride ion.

2. Gloeobacter rhodopsin

Fig. 2 shows TR3 spectra of GR. In the spectra probed at 475 nm, the C–C, C=C, and C=NH+ stretch bands were observed at 1199, 1534, and 1642 cm−1, respectively, in the unphotolyzed state (GR). At 300 ns, in addition to prominent bands at 1192, 1538, and 1623 cm−1, weak bands were observed at 1184, 1549, and 1652 cm−1. The latter three bands became noticeable in the 10-µs spectrum. Intensity ratios of the pairs of the observed bands changed from 300 ns to 10 µs, suggesting that two intermediates appears in this temporal region. The later intermediate was assigned to the L intermediate according to the previous absorption study of GR [5]. In milliseconds, new bands appeared at 1534 and 1650 cm−1, which can be attributed to the N intermediate. In the spectra probed at 400 nm, rise and decay of the band only due to M were observed. It was found that the temporal behavior of rise and decay of M was similar to that of L. This implies that the equilibrium between L and M was quickly achieved. The deuteration shift of the C=NH+ band were also observed in the GR photocycle. The C=NH+/C=ND+ stretch bands were observed at 1642/1628, 1623/1614, 1652/1623, and 1650/1621cm−1 in the TR3 spectra probed at 475 nm, respectively. However, the deuteration shift was not observed in M, because the chromophore in M is deprotonated.

The highest C=NH+ stretching frequency and large deuteration shift showed in L, suggesting that the strong hydrogen bond forms in PSB. Transition from L to M accompanies the deprotonation in PSB. Strengthening the hydrogen bond between PSB and the counterion facilitates a proton release. The equilibrium between L and M is contrast to the BR photocycle, in which M sequentially forms from L [6]. The characteristic behavior of GR implies that PSB in the chromophore strongly interacts with the proton acceptor, Asp121, through the hydrogen-bond network upon the M formation. Our results lead us to hypothesize that the counterion approaches to PSB upon L formation, in lowering barrier height of the proton transfer.

References [1] T. Althaus, W. Eisfeld, R. Lohrmann, M. Stockburger, Israel J. Chem. 35 (1995), 227–251. [2] G. Váró, Biochim. Biophys. Acta 1460 (2000), 220–229. [3] S. O. Smith, M. S. Braiman, A. B. Myers, J. A. Pardoen, J. M. L. Courtin, C. Winkel, J. Lugtenburg, R. A. Mathies, J. Am.

Chem. Soc. 109 (1987), 3108–3125. [4] M. Shibata, N. Muneda, T. Sasaki, K. Shimono, N. Kamo, M. Demura, H. Kandori, Biochemistry 44 (2005), 12279–12286. [5] M. R. M. Miranda, A. R. Choi, L. Shi, A. G. Bezerra Jr., K. -H. Jung, L. S. Brown, Biophys. J. 96 (2009), 1471–1481. [6] R. Diller, M. Stockburger, Biochemistry 27 (1988), 7641–7651.

Fig. 2. TR3 spectra of GR probed at (a) 475 nm and (b) 400 nm. The top black traces are the probe-only spectra. The other grey traces are time-resolved difference spectra. The asterisk in (b) is the band due to the species having absorption maximum at 400 nm.


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Photoisomerization Action Spectroscopy – Using Light to Change the Shape of Molecular Ions B. D. ADAMSON1, N. J. A. COUGHLAN1, P. MARKWORTH1 AND E. J. BIESKE1*

1School of Chemistry, University of Melbourne, 3010, Australia [email protected]

Molecular photoisomerization plays a crucial role in biological systems (cis-trans isomerization of retinal in animal

vision and bacterial photosynthesis) and in molecular technologies (light activated molecular machines). To understand these systems it is desirable to gather information on the photoisomerization behaviour of the core molecules in the gas phase. For this purpose we have developed a tandem ion mobility apparatus in which a certain isomer population is selected in a first IMS stage, followed by excitation by photons from a laser or buffer gas collisions, with the resulting product isomers separated in a second IMS stage. Using the IMS-photo-IMS arrangement one can measure the photoisomer intensity as a function of laser wavelength, yielding a photoisomerization action spectrum, which, under favourable circumstances, mirrors the isolated molecule’s absorption spectrum. This is the basis for a new form of action spectroscopy for molecular ions – photoisomerization action (PISA) spectroscopy. Alternatively, with a IMS-collision-IMS arrangement one can select a particular isomer and monitor its transformation to product isomers as the collision energy is increased. This provides information on the magnitude of isomerization barriers. This combination of photo and collisional excitation can be used to map out the isomeric landscape of molecular ions, and is illustrated using several examples, including the retinal protonated Schiff base and merocyanine molecules.

The approach has been used to obtain electronic spectra of isomers of the retinal protonated Schiff base (RSPB). Reliable spectroscopic and photochemical data for the isolated retinal molecule are essential for calibrating theoretical approaches that seek to model retinal's behaviour in complex protein environments. However, due to low densities and possible co-existence of multiple isomers, retinal is a challenging target for gas-phase investigations. The photoisomerization action spectrum of trans RPSB, obtained by monitoring production of cis isomers as a function of wavelength, exhibits a single well-defined peak with a maximum at 618 nm. Corresponding action spectra of cis RPSB isomers exhibit broader peaks, conclusively demonstrating that the RPSB spectrum in the gas phase depends on conformation. References [1] B.D Adamson, N.J. A. Coughlan, P. Markworth, R.E. Continetti, E.J. Bieske, Rev. Sci. Instr.}, 85 (2014) 123109. [2] N.J. A. Coughlan, K. Catani, B.D Adamson, U. Wille, E.J. Bieske, J. Chem. Phys., 140, (2014) 164307.

Fig. 1. Tandem ion mobility apparatus for obtaining photoisomerization action spectra of molecular ions.


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Spectral enhancement of lanthanide doped luminescent hybrid nanosystem H. R. ZHENG1*, W. GAO1, E. J. HE1, Q. Y. HAN1, AND J. DONG1

1School of Physics and Information Technology, Shaanxi Normal University, Xi’an, 710062, China, [email protected]

Rare-earth (RE) ions have been widely applied to luminescent materials because of their unique luminescent properties that originated from 4F electron configuration, which include sharp luminescence band, long excited state life time, abundant emission bands, low luminescence backgrounds, etc. However, the low quantum efficiency of Ln3+ ions has limited their applications, and efforts on the exploration on the efficiency improvement have never been stopped. Except for the traditional strategies, achievement in the field of plasmonics offers us an alternative way to enhance the luminescence emission of Ln3+ doped luminescent materials.

In current talk, we will report our recent investigation on the fluorescence enhancement with metallic nanoparticles for Ln3+ doped luminescent hybrid nanosystem. As an example, LaF3:Yb3+/Ln3+@SiO2 (Ln=Er, Tm) nanosystem decorated Ag nanoparticles will be discussed intensively, and the observation of surface plasmon resonance (SPR) broadening and its red-shift by adjusting the size and configuration of Ag nanoparticles will be presented too. These specially designed systems present an efficient way to investigate the possible mechanism and specific processes of the luminescence enhancement, and explore the possible interaction between the metal nanosystem and the luminescence centers, as shown in Figure 1.

The luminescence property of single luminescent particle is important for the study of the enhancement with plasmonic effect. Therefore the study on the unusual upconversion emissions with a candy-like pattern from an isolated single NaYF4: Yb3+/Ho3+ microrod will be also presented. The overall luminescence color and spectral dependence on the particle number will be discussed too, as shown in Figure 2.

Acknowledgement We thank the National Science Foundation of China (Grant No. 11174190 and 11304247) for supporting. References [1] E. J. He, M. Moskovits, J. Dong, W. Gao, Q. Y. Han, H. R. Zheng, N. Liu,

Plasmonics, 10(2015), 357-368. [2] E. J. He, H. R. Zheng, J. Dong, W. Gao, Q. Y.n Han, J. N. Li, L. Hui, Y. Lu and H. N. Tian, Nanotechnology, 25(2014), 045603. [3] W. Gao, H. R. Zheng, Q. Y. Han, E. J. He, F. Q. Gao, R. B. Wang, Journal of Materials Chemistry C., 2(2014), 5327-5334.

Fig. 2. UC emission spectra of single NaYF4:Yb3+/Ho3+ microrods (a), double NaYF4:Yb3+/Ho3+ microrods (b), multiple NaYF4:Yb3+/Ho3+ microrods (c) under 980 nm excitation.

Fig. 1. Schematic energy level diagram of and the suggested relaxation processes in the samples with and without Ag NPs


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Spectroscopic study of anomalous charge distributions in molecular ions S. K. KIM1

1Department of Chemistry, Seoul National University, Seoul 151-747, Korea, [email protected]

An electrostatic charge can in principle be “divided” into multiple sites within a molecule, but no direct evidence has so far been presented that supports such “charge division”. In our study of photoionized L-phenylalanine, we found an indication for cationic charge division and obtained clear experimental evidence [1]. Upon ionization, one of the two conformeric classes of phenylalanine was found to have its charge divided between the amino group and the phenyl ring. Two telltale signs of charge division were noted: the planarity of the C−NH2 group and the marked elongation of the C−C bond to an unprecedented length of 1.7 Å. Charge division endows a significant neutral character to the phenyl ring in the cation, which leads to the drastic blue shift of its absorption, as experimentally verified by the conformation-dependent fragmentation propensity.

In our study of a loosely bound electron in the anion clusters of polycyclic aromatic hydrocarbon, a particularly interesting observation was made that an electron binds to the complex of pyridine and CO2 in what appears to be “associative” electron attachment that turns the van der Waals bond between the two moieties into a covalent one [2]. This is significant since both pyridine and CO2 individually have negative adiabatic electron affinities yet their complex appears to readily accommodate an extra electron. In the anionic pyridine–CO2 complex, the extra electronic charge is nearly equally divided between the pyridinic ring and CO2 through what appears to be an extended π-network. Similar cases were also found with other azabenzene species, O2, and even some noble metals that may very well be used to “activate” CO2 in the presence of a negative charge. Acknowledgement I acknowledge Drs. K. T. Lee, H. M. Kim, K. Y. Han, J. Sung, S. H. Lee, N. Kim, and D. G. Ha for their contributions to this work. References [1] K. T. Lee, H. M. Kim, K. Y. Han, J. Sung, K. J. Lee, S. K. Kim, J.Am.Chem.Soc. 129 (2007), 2588-2592. [2] S. H. Lee, N. Kim, D. G. Ha, S. K. Kim, J.Am.Chem.Soc. 130 (2008), 16241-16244.


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C2 – A Remote Probe for Combustion and Astrophysics O. KRECHKIVSKA1, G. B. BACKSAY2, T. P. TROY2, K. NAUTA1, S. H. KABLE1 AND T. W. SCHMIDT1* 1School of Chemistry, UNSW Sydney, 2052, NSW, Australia [email protected] 2School of Chemistry, The University of Sydney, 2006, NSW, A

The dicarbon molecule is the 7th most abundant neutral molecular species in the universe, as visible from Earth. It inhabits the photospheres of carbon stars and pervades the interstellar medium. It also dominates the emission spectrum of many comets, and is responsible for the principal component of the blue coloration of hydrocarbon flames. In recent times the C2 species has also revived interest among theoreticians, some arguing that it exhibits a quadruple bond in its ground electronic state.

The electronic spectroscopy of C2, despite being a seemingly simple molecule, is rich and complex. Even with rigorous selection rules requiring g ↔ u, + ↔ +, − ↔ −, and Δλ =0, ±1, there are at least 18 reported band systems involving 21 electronic states of singlet, triplet and quintet spin multiplicities. Despite the long history of spectroscopic reports on C2, there remains unexplored spectroscopy: The 15Πg state was reported as recently as 2011, with the first quintet-quintet band system, 15Πu − 15Πg (Radi-Bornhauser System), reported as recently as this year.

Despite this large body of knowledge, there remains to be reported a satisfactory explanation for the appearance of cometary C2 spectra. Modelled spectra of the Swan bands are too hot, with previous investigators circumventing this problem by assuming the intercombination transitions between the singlet and triplet systems to be an order of magnitude stronger than what they are known to be. Recently, we proposed that C2 might be photodissociated before reaching photophysical equilibrium. This prompted us to probe new spectroscopy, above the dissociation limit.

In this talk I will describe my group’s contribution to knowledge about the C2 molecule, including the latest work: the first 1 + 1 resonant ionization spectrum of C2 in its lowest triplet state. We have uncovered a new band system: 43Πg − a3Πu, with the identification greatly enabled by highly accurate ab initio calculations and hole-burning spectroscopy. This new knowledge of spectroscopically accessible states of C2 above the dissociation threshold allows us to test our hypothesis that accessing such states result in destruction of C2 when placed in front of a 6000 K light source such as the Sun.

Acknowledgement This research was funded by the Australian Research Council (grant DP120102559). It was also undertaken with the assistance of resources from the National Computational Infrastructure (NCI), which is supported by the Australian Government. T.W.S. acknowledges the Australian Research Council for the award of a Future Fellowship (FT130100177). References [1] O. Krechkivska, G.B. Bacskay, T.P. Troy, K. Nauta, T.D. Kreuscher, S.H. Kable, and T.W. Schmidt, J. Phys. Chem. A, Just Accepted Manuscript, DOI: 10.1021/acs.jpca.5b05685

Fig. 1. Observed and simulated band terminating on a new electronic state of C2 – the 43Πg state (v = 1).

ACOVS11/ASC5 Book of Abstracts Session IX – Synchrotron THz

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SESSION IX – SYNCHROTRON THZ


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Synchrotron far-IR characterization of self-assembling β3 peptides A. MECHLER1*, R. SEOUDI1, K. KULKARNI2, M. DELBORGO2, P. PERLMUTTER3, M.-I. AGUILAR2 AND A. DOWD4 1Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Australia. [email protected] 2Department of Biochemistry & Molecular Biology, Monash University, Australia. 3School of Chemistry, Monash University, Australia. 4School of Physics and Advanced Materials, University of Technology Sydney, Australia

Unnatural β3-amino acids exhibit exceptionally well defined molecular geometries by folding into a helix that has a pitch of nearly exactly 3.0 amino acids per turn. This structure, known as 14-helix based on the number of atoms of the backbone making a complete turn, is stabilized by three H-bonds per turn between the backbone amide groups, the alignment of which is nearly parallel to the main axis of the helix. Thus in this geometry the amide groups have a nearly identical chemical environment with highly preserved long range order. By designing a self-assembly motif that allows the continuation of the helix via an intermolecular repeat of the intramolecular H-bonding motif it is possible to extend this ordered structure to microns or even millimeters[1-3].

The characterization of these β3-peptide-based helical structures poses a unique problem. The main evidence that the self-assembly motif works is the observation of long fibres with microscopic methods, and a few crystal structures. However there is no evidence that the self-assembly follows the same pathway in a colloidal fibre as it does in the crystal, or that the fibres observed are really the results of head-to-tail self-assembly.

To obtain at least an indirect answer to this problem, far-IR spectroscopy was performed to probe the order and symmetry of the peptide fibres. Experiments have been performed on three isomeric peptides comprising the same three β3-amino acid residues: β3-leucine (L), β3-isoleucine (I) β3-alanine (A) to give peptides Ac-β3[LIA], Ac-β3[IAL] and Ac-β3[ALI]. There is microscopic evidence that these peptides self-assemble into long fibres, albeit with a markedly different superstructure. The well defined synchrotron far-infrared spectra (Fig 1) reveal uniform geometries with a high degree of similarity between the isomeric peptides in the amide modes of the 400-650 wavenumber range.

The band at ~600 cm-1 is prominent for all three peptides, although somewhat broadened in the case of Ac-β3[IAL] and Ac-β3[ALI]. This band is identified as Amide VI, out-of-plane C=O bending, which is known to be highly sensitive to the chemical environment and the folding geometry, varying between 550 cm-1 and 650 cm-1. However, the peak position in Fig 1 is the same for all three peptides, confirming that the isomeric peptides have an identical structure, consistent with the 14-helical structure. The strong band at ~470 cm-1originating from O=C-N deformation is sensitive to the geometry of H-bonds; it is shifted to different degrees in the three isomeric peptides revealing differences in hydrogen bond pattern and strength as well as coupling to skeletal and side chain motion.

The C-terminal carboxyl of these peptides is protonated and is free for inter-fibril H-bonding, or to be solvated. Accordingly, carboxyl bands carry information about the packing of the fibres. The [26] is seen in all three peptides at the same position, suggesting that the carboxyl groups do not participate in H-bonds in the dry deposit.

The COO mode at ~617 cm-1 also confirms that the C-terminal carboxyl group is free in the assemblies, thus it is solvated in the dispersant. DFT calculations supported the above interpretations. Hence, the fibres have the same highly preserved core structure which is consistent with the head-to-tail self-assembly, while the differences in the superstructures formed by the fibres are the results of intermolecular interactions. Acknowledgement The authors acknowledge Dr Joonsup Lee (University of Sydney) for helping with far-infrared spectroscopic data collection and Dr Dominique Appadoo at the Australian Synchrotron for his invaluable insight and technical assistance. Part of this research was undertaken on the THz/Far-IR beamline at the Australian Synchrotron, Victoria, Australia. References [1] Del Borgo, M. P.; Mechler, A. I.; Traore, D.; Forsyth, C.; Wilce, J.A.; Wilce, M. C. J.; Aguilar, M.-I.; Perlmutter, P.:

Supramolecular Self-Assembly of N-Acetyl Capped b-Peptides Leads to Nano-to Macroscale Fibre Formation. Angew. Chem. and Angew. Chem Int. Ed. 52 (32) 8266-8270 (2013)

[2] Rania S. Seoudi, Mark P. Del Borgo, Ketav Kulkarni, Patrick Perlmutter, Marie-Isabel Aguilar and Adam Mechler Supramolecular self-assembly of 14-helical nanorods with tunable linear and dendritic hierarchical morphologies New J. Chem. 39 (5) 3280-3287 (2015

[3] Rania S. Seoudi, Annette Dowd, Mark Del Borgo, Ketav Kulkarni, Patrick Perlmutter, Marie-Isabel Aguilar and Adam Mechler: Amino acid sequence controls the self-assembled superstructure morphology of N-acetylated tri-β3-peptides Pure and Applied Chemistry, in press

Fig. 1. Far-IR spectra (absorbance) of isomeric peptides Ac-β3[LIA], Ac-β3[IAL] and Ac-β3[ALI] (from [3]).


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THz/Far-IR condensed-phase capabilities & studies at the Australian Synchrotron D. APPADOO1*, R. PLATHE1, C. MEDCRAFT2, A. WONG3, AND C. ENNIS4 1 The Australian Synchrotron, 800, Blackburn Rd, Clayton, VIC 3168 2 Center for Free-Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg, Germany. 3 Monash University, Wellington Rd, Clayton, VIC 3800 4 Department of Chemistry and Physics, Latrobe Institute for Molecular Sciences, Latrobe University, Melbourne, 3086, Victoria, Australia

The THz/Far-IR beamline at the Australian Synchrotron is coupled to a Bruker IFS125 Fourier transform spectrometer equipped with optics and detectors covering the spectral range from 10 to 5000 cm-1. There is a variety of instruments at the beamline to accommodate the diverse requirements of the User community. For the gas-phase community, we have a couple of room-temperature cells and a cryogenic cell with variable path-length optics to study weakly absorbing or weakly-bound gases [1-3]; these cells can be coupled to furnaces to study short-lived radicals by pyrolysis [4]. Condensed-phase Users have access to a couple of cryostats for transmission studies down to 77 K and down to 6 K [5-8]; we have just designed a set of liquid-cells with diamond windows that can be coupled to the cryostats. Users also have access to a grazing incidence angle accessory [9] and a near-normal accessory to study condensed phase systems in reflection mode; they also have access to a Linkam-based furnace which can be coupled to the near-normal reflection accessory. A 25W cw CO2 laser and a 10 Hz 480 mJ Nd:YAG laser have recently been installed at the beamline for photolysis studies, and we are presently developing low-temperature deposition technique for reflection studies.

The synchrotron infrared light offers a signal-to-noise advantage over conventional thermal sources, and the magnitude of this advantage varies to a great degree upon the spectral range, sample size and the spectral resolution required by the experiment. In this paper, some applications undertaken at the beamline, and future developments, as well as the capabilities of the THz/Far-IR beamline will be presented. References [1] C. Medcraft, D. McNaughton, C. Thompson, D. Appadoo, S. Bauerecker, and E. Robertson, PCCP., 2013, 15, 3630. [2] H. Bunn, T. Bennett, A. Karayilan, P.L. Raston, Astrophys. J., 2015, 799 (1), 65. [3] R.J. Hargreaves, P.F. Bernath, and D.R.T. Appadoo, J. Mol. Spec., 2015, in press [4] Wong, C. Thompson, D. Appadoo, R. Plathe, P. Roy, L. Manceron, J. Barros, and D. McNaughton, Mol. Phys. 2013, 111 (14-

15), 2198. [5] M. Minakshi, D. Meyrick, and D. Appadoo, Energy Fuels, 2013, 27, 3516. [6] T. Bennett, R.H. Adnan, J.F. Alvino, V. Golovko, G.G. Andersson, and G.F. Metha, Inorg. Chem., 2014, 53, 4340. [7] G.M. Png, B.M. Fischer, D. Appadoo, R. Plathe, D. Abbott, Opt. Exp. 2015, 23, 4997. [8] T. Ding, A. Middelberg, T. Huber, and R. Falconer, Vibrational Spec., 2012, 61, 144. [9] K. Lepková, W. van Bronswijk, V. Pandarinathan, R. Gubner, J. Of Synch. Rad., 2014, 21, 580.


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High-resolution synchrotron FTIR spectroscopy of cis-ethylene-d2 (cis-C2H2D2): rovibrational constants of the ground and ν7 = 1 states

T. L. TAN1,*, G. ARUCHUNAN1, L. L. NG1, M. G. GABONA1, A. WONG2, D. R.T. APPADOO3, AND D. MCNAUGHTON2

1 Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616, Singapore 2 School of Chemistry, Monash University, Wellington Rd., Clayton, Victoria 3800, Australia 3 Australian Synchrotron, 800 Blackburn Rd., Clayton, Victoria 3168, Australia *Corresponding author. Fax: +65 68969125 E-mail address: [email protected]

The Fourier transform infrared (FTIR) absorption spectrum of the ν7 fundamental band of cis-ethylene-d2 (cis-C2H2D2) was recorded in the 720-990 cm-1 region with a resolution of 0.00096 cm-1 on a Bruker IFS 125HR Michelson spectrophotometer using the THz/far-infrared beamline of the Australian Synchrotron [1]. All spectra were recorded at 296 K with a liquid nitrogen cooled Hg-Cd-Te detector and KBr beam splitter at cis-C2H2D2 vapor pressure of 5 mTorr using a multiple- pass gas cell (of 55-cm base path length) which was adjusted for 16 passes to give an optical path length of 8.80 m. The total scanning time for the final spectrum was about 8.3 hours to give a signal-to-noise ratio higher than 20. The average Doppler full-width at half maximum (FWHM) of the lines in the spectrum was about 0.002 cm-1. The absolute accuracy of the measured cis-C2H2D2 lines was estimated to be ±0.0002 cm-1. Figure 1 shows the survey experimental high-resolution spectrum of the ν7 band of cis-C2H2D2 in the 720-990 cm-1 region.

Upper state (ν7 = 1) rovibrational constants consisting of three rotational constants and up to three sextic terms were

derived by assigning and fitting more than 2500 infrared transitions (including more than 600 new transitions) using Watson’s A-reduced Hamiltonian in the Ir representation [2]. Figure 2 shows the assignments of transitions in the RQ6 (Kaʺ = 6) cluster in the R branch region of 875.35 to 876.65 cm-1. Asymmetric splitting was observed from J = 16 onwards in this cluster. The band centre at 842.2 cm-1 of the relatively unperturbed C-type ν7 band was also determined. The present analysis, covering a wider wavenumber range and higher J and Kc values than that previously reported [3], yielded upper state constants including the band centre which are more accurate than previously reported [3]. The root mean square (rms) deviation of the upper state (ν7 = 1) fit was better than 0.0003 cm-1.

Fig. 5. Experimental high-resolution spectrum (720-990 cm-1) of the ν7 band of cis-ethylene-d2 (cis-C2H2D2).


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Improved ground state rovibrational constants were also determined from the fit of more than 1200 ground state

combination differences (GSCDs) from the presently-assigned transitions of the ν7 band of cis-C2H2D2 using Watson’s A-reduced Hamiltonian in the Ir representation. The rms deviation of the GSCD fit was better than 0.0003 cm-1. The ground state constants of cis-C2H2D2 derived from the experimental GSCD fit were found to be in good agreement with the equilibrium state constants obtained from theoretical calculations using the B3LYP/cc-pVTZ, MP2/cc-pVTZ, and CCSD/cc-pVTZ levels, up to five quartic constants [3]. The GAUSSIAN09 program was used in the calculations [4]. Acknowledgement The authors are grateful to the Australian Synchrotron, Victoria, Australia for the recording of the cis-C2H2D2 spectra using the high-resolution THz/far-infrared beamline. Financial support by the National Institute of Education, Singapore through research grant number RS 7/11 TTL is acknowledged. References [1] T.L. Tan, M.G. Gabona, Dominique R. T. Appadoo, Peter Godfrey, Don McNaughton, J. Mol. Spectrosc. 303 (2014) 42-45. [2] J.K.G. Watson, in: J.R. Durig, (Ed.), Vibrational Spectra and Structure: A Series of Advances, Vol. 6, Chapter 1, Elsevier, New

York, 1977 [3] T.L. Tan, G.B. Lebron, J. Mol. Spectrosc. 261 (2010) 87-90. [4] M.J. Frisch, G.W. Trucks, H.B. Schlegel, et al., GAUSSIAN09, Gaussian, Inc., Wallingford, CT, USA, 2009.

Fig. 2. Detail of the spectrum in the R branch region (875.35 to 876.65 cm-1) of the ν7 band of cis-C2H2D2 showing the assignments of transitions of the RQ6 (Kaʺ = 6) cluster.

ACOVS11/ASC5 Book of Abstracts Session X – Materials II

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SESSION X – MATERIALS II


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Interlayer Vibrational Modes in 2D Transitional Metal Dichalcogenides Q. XIONG School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371 Email Address: [email protected]

We discuss the lattice vibrational modes in a wide range of two-dimensional layered materials, transition metal dichalcogenides, bismuth chalcogenides and black phosphorus and etc, with a focus on interlayer vibrational properties. We will start with a discussion on the thickness-dependent properties of the phonon modes, resulting from reduced dimension and lower symmetry when thickness decreases from bulk to monolayer, for instance phonon confinement. We will then focus on the interlayer shear and breathing modes. By showing the interlayer vibrational modes in different materials, we demonstrate that the low-frequency interlayer modes are universal in two-dimensional materials, but small variation also exists, such as the low-frequency interface mode in Bi2Te3 and the strong angle-dependent A3

g mode in black phosphorus. The dependence of the frequency of the interlayer modes and their selection rules can be understood from the linear-chain model and first principle computations. Besides thickness-dependence, stacking-related low-frequency interlayer shear mode and bond polarizability model will also be discussed.


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Coupling between excited states in TPA-substituted pyridyl-triazole complexes G. S. HUFF1, W. K. C. LO1, J. D. CROWLEY1, K. C. GORDON1 1Department of Chemistry, University of Otago, P.O. Box 56, Dunedin, New Zealand [email protected]

A pyridyl triazole ligand has been studied as an analog to 2,2’-bipyridine (bpy). Its Re(I)(CO)3Br, Pt(II)Cl2 and Ru(II)(bpy)2 complexes have been studied with transient absorption spectroscopy, resonance Raman spectroscopy and density functional theory. Photophysically the Pt(II) and Re(I) complexes behave similarly to the analogous bpy complexes while the Ru(II) complex is found to be non-emissive in fluid solution due to a low-lying metal centered triplet state which leads to rapid ligand ejection.

Substitution of the ligand with triphenyl amine (TPA) results in enhanced visible absorption by the complexes due to the addition of an intraligand charge transfer (ILCT) band to the absorption spectrum. Interplay between the ILCT state and MLCT states of the three metal complexes is found to vary quite drastically.

Resonance Raman spectroscopy shows that the 1ILCT state in the Re(I) and Pt(II) complexes is lower in energy than the MLCT state while it is higher in the Ru(II) complex. The Ru(II) complex relaxes through a metal centered state like its parent molecule. The Re(I) complex appears to emit from a relaxed 3MLCT state while the Pt(II) complex emits from an ILCT state. To our knowledge this is only the second example of an emissive Pt(II) dichloride complex. The Pt(II) complexes show resonant de-enhancement of some vibrational modes when the MLCT band is probed due to overlap with forbidden d-d transitions which in most Pt(II) dichlorides cause non-radiative decay of the excited states. We plan to examine this further by replacement of the chloride ligands with stronger donors.

The excited state lifetimes of the TPA-substituted complexes at room temperature are too short to measure using nanosecond transient absorption spectroscopy. However, picosecond time-resolved experiments are underway to gain insight into the excited state dynamics of these complexes.

References [1] Lo, W. K. C.; Huff, G. S.; Cubanski, J. R.; Kennedy, A. D. W.; McAdam, C. J.; McMorran, D. A.; Gordon, K. C.; Crowley, J. D. (2015) Comparison of Inverse and Regular 2-Pyridyl-1, 2, 3-triazole “Click” Complexes: Structures, Stability, Electrochemical, and Photophysical Properties, Inorg. Chem., 54, 1572-1587.


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Analysis of Experimental Spectra (FT-IR, FT Raman, UV and NMR) of some pharmaceutical compounds based on Density Functional Theory Calculations A. GUPTA1 AND M. AGRAWAL1 1Department of Applied Physics, Faculty of Engineeing and Technology, M.J.P. Rohilkhand University, Bareilly, U.P., India [email protected]

Spectroscopic studies of benzene and its derivatives have been motivated by their pharmaceutical importance. The title compound 4-(6-methoxy-2-naphthyl)-2-butanone commonly known as Nabumetone (NBM) is used to treat pain or inflammation caused by arthritis. Nabumetone works by reducing the effects of hormones that cause pain and inflammation [1].

In this work we report a combined experimental and theoretical study on the vibrational spectra of some pharmaceutical molecules Nabumetone and Levosimendan. DFT calculations have been done at B3LYP/6-311++G(d,p) level using Gaussian 09 in order to derive the optimized geometry. The optimized geometry of nabumetone molecule is shown in figure 1.

Figure 1: Optimized structure of 4-(6-Methoxy-2-Naphthyl)-2-Butanone FT-infrared and Raman spectra of NBM have been recorded in the region 4000-400 cm-1 and 3200-100 cm-1

respectively. The vibrational spectra have been analyzed by means of normal-mode calculations. The experimental spectra coincide satisfactorily with those of theoretically simulated spectrograms. Experimental and calculated FT-IR spectra of NBM is shown in figure2.

The total no. of atoms in this molecule is 33, hence it gives 93 (3N-6) normal modes The very strong band observed at 1707 cm−1 in FT-IR and 1703 cm−1 in Raman spectra for NBM are assigned to C=O stretching vibrations, which is calculated at 1744 cm−1. The peaks observed at 1504, 1485, 1416, 1389 cm-1 in the FT-IR spectrum and at 1523, 1484, 1414, 1387 cm-1 in the Raman spectrum are assigned to C-C aromatic stretching vibration. These modes have contributions from C-H in plane bending vibrations also. The CH3 rocking modes observed at 1175 and 895 cm-1 in the FT-IR spectra and at 1177, 893 cm-1 in the Raman spectra match well with the bands calculated at 1163 and 914 cm-1.

Aqueous solubility and lipophilicity have been calculated which are crucial for estimating transport properties of

organic molecules in drug development and reflect the key event of molecular desolvation in transfer from aqueous phases to cell membranes and to protein binding sites. Estimation of biological effects, toxic/side effects has been made on the basis of prediction of activity spectra for substances (PASS) prediction results and their analysis by Pharma Expert software. References [1] Barbara J. Lister, M.D. Marcia Poland, M.A, Ralph E. DeLapp, M.S, The A. J. Med. 95 (1993)2-9.

Figure 2: Experimental and calculated FT-IR spectra of NBM

ACOVS11/ASC5 Book of Abstracts Session XI – Single Molecules

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SESSION XI – SINGLE MOLECULE


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Single molecule super-resolution imaging of microtubules in cells expressing Rabies virus proteins T. D. M. BELL1, D. R. WHELAN2, A. BRICE3 AND G. W. MOSELEY3

1Monash University, Wellington Road, Clayton, 3800, Victoria, Australia. [email protected] 2New York University, 1st Avenue, New York, 10016, New York, USA. 3The University of Melbourne and Bio21 Institute, Flemington Road, Parkville, 3010, Victoria, Australia.

Interferon (IFN)-mediated immunity is a central mode of defense against viral infection and evasion of this immune response is critical to the pathogenicity of viruses. IFN-antagonist proteins have recently been shown to interact with host microtubules (MTs) demonstrating a novel mechanism for subverting the IFN response [1].

Using super-resolution single molecule localization microscopy (SMLM) [2] we show that the rabies virus (RABV) IFN-antagonist P3 induces significant structural changes to the MT network consistent with MT-filament bundling (Figure 1).

Furthermore, we show that the capacity of P3 to interact with and bundle MTs correlates with viral pathogenicity in vivo, and using viral reverse genetics, identify a single mutation of P3 that strongly inhibits these processes. This study demonstrates that MT-interactionand bundling by an IFN-antagonist has roles in virulence, providing new insights into the viral-host interface.

References [1] K. G. Lieu, A. Brice, L. Wiltzer, B. Hirst, D. A. Jans, D. Blondel, G. W. Moseley, J. Virol. 87 (2013), 8621–8625. [2] D. R. Whelan, T. D. M. Bell, J. Phys. Chem. Lett. 6 (2015), 374–382.

Fig. 1. SMLM image of a COS-7 cell transfected to express RABV P proteins and labeled for tubulin with Alexa 647. Expanded regions show MT features much larger than expected for a single MT and consistent with bundling


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Donor-Acceptor Interactions of 2,1,3-Benzothiadiazole Push-Pull Dyes; An Experimental and Computational Study J. E. BARNSLEY1, C. B. LARSEN1, G. SHILLITO1, H. VAN DER SALM1, N. T. LUCAS1 AND K. C. GORDON1

1University of Otago, 362 Leith St, North Dunedin, Dunedin 9016, Otago, New Zealand [email protected] MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, Dunedin, New Zealand

Organic donor-acceptor dyes have been of significant interest in the recent decades for use in organic photovoltaic (OPV’s) devices. 2,1,3-Benzothiadiazole has been recognised as a promising acceptor moiety in these a result of a low bandgap and easily tuneable optical properties through functionalization resulting in improved hole/electron affinity.[1] These properties are ideal for increasing the short-circuit current density (Jsc) and open-circuit voltage (Voc) that stifles efficient OPV operation.[2]

The relationship between donor and acceptor group has a significant effect on the charge transfer found in these systems and can promote or hinder performance. Hence the influence of donor-acceptor torsional angle and the interplay of linker and donor groups becomes exceedingly important to understand.

To develop this molecular electronic understanding, one widely used tool is Density functional theory (DFT). DFT calculations, however, are prone to issues with accuracy due to incorrect usage. Increasingly it becomes important to understand what computational methods are most suitable for a compound series of interest.

In this talk, a series of BTD compounds will be discussed with varying degrees of steric bulk as to provide a range of donor-acceptor torsion angles. Also included are several permutations of the BTD-donor framework to investigate, linker and donor effects on this charge transfer system. The consequence of these effects has been investigated both optically and vibrationally. Finally, the ability of six Density Functional Theory (DFT) methods calculations across solvent and compounds will be discussed; paying attention to what effects Hartree Fock or orbital exchange contribution have on predicted data for these systems. References [2] B. A. N. Neto, A. A. M. Lapis, E. N. Da Silva Júnior, J. Dupont, European Journal of Organic Chemistry 2013, 2, 228. [2] B. Kippelen and J. L. Brédas, Energy & Environmental Science 2009, 2, 251.

Fig. 1. The base BTD-donor framework investigated in this study.


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Time-Resolved and Polarised Evanescent Wave-Induced Fluorescence Spectroscopic Measurements of Fluorophores Near an Interface H. SOLEIMANINEJAD1, T. A. SMITH1 AND C. A. SCHOLES2

1Ultrafast and Microspectroscopy Laboratories, School of Chemistry, University of Melbourne, Victoria 3010, Australia. [email protected] 2 Departments of Chemical and Biomolecular Engineering, University of Melbourne, Victoria 3010, Australia

Total internal reflection (TIR) (or evanescent wave (EW)) induced fluorescence techniques can be used to study the photophysical properties of dyes and polymers in close (~100 nm) proximity to interfaces. Varying the angle of incidence of the excitation light affords a level of control over the penetration depth of the evanescent field into the medium of lower refractive index, and thereby provides a means to probe properties that vary from the interfacial region to the bulk solution. By recording fluorescence decay information following EW-excitation provides significant advantages and additional information to that accessible through steady-state measurements.

The unique capabilities of TIR fluorescence methods can also be further exploited by using polarised excitation and emission detection.(1) We have performed time-resolved EW-induced fluorescence anisotropy measurements to probe molecular photophysics, motion and conformational change in the interfacial region. This approach allows phenomena to be probed with some discrimination between processes occurring in- and out-of the plane of the interface.

We have applied time-resolved EW-induced fluorescence techniques and EW-induced fluorescence anisotropy measurements to study the adsorption of dyes, thin polymer films and supported bilayers on silica surfaces to probe the variation in the photophysical behaviour as a function of distance from the interface.

We have recorded complex time-dependent fluorescence anisotropy data from relatively “simple” systems. For example Acridine within a polymer film, shows strong time dependence of the fluorescence anisotropy signal with “dip and rise” trends obvious, and different behaviour is observed for in- and out-of-plane measurements with the out-of-plane signal changing sign.(2)

We report here the application of these approaches to investigate the location, orientation and mobility of fluorophores at the silica/solution interface. In particular we have investigated the photophysical behaviour of “molecular rotor”-type molecules such as Auramine O.

References [1] M.L. Gee, L. Lensun, T.A. Smith and C.A. Scholes, Eur. Biophys. J., 33 (2004) 130-139 [2] T.A. Smith, M.L. Gee and C.A. Scholes, in Reviews in Fluorescence, C.D. Geddes and J.R. Lakowicz (Eds), Springer Science

(2005), 245-270.

ACOVS11/ASC5 Book of Abstracts Session XII – Agriculture

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SESSION XII – AGRICULTURE


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Prediction of lamb meat quality using a Raman spectroscopic hand held device S. M. FOWLER1,2, H. SCHMIDT3, R. VAN DE VEN4 AND D. L HOPKINS1, 2 1 Centre for Sheep and Red Meat Development, NSW Department of Primary Industries, Cowra, Australia [email protected] 2 Graham Centre for Agricultural Innovation, NSW Department of Primary Industries and Charles Sturt University, Wagga Wagga, Australia 3 Research Centre of Food Quality, University of Bayreuth, Kulmbach, Germany 4 Orange Institute of Agriculture, NSW Department of Primary Industries, Orange, Australia

Carcase assessment is a continuing challenge for lamb processors in Australia, as lamb carcases are still commonly

assessed for market suitability on only weight and fat score. While informative for meat yield, these attributes are variable and may not be indicative of eating quality characteristics, such as tenderness. Consequently better carcase assessment methods are required by the sheep meat industry.

Raman spectroscopy is a technology of interest as it is rapid, non-destructive, non-invasive, requires no sample preparation and is not affected by varying water content. This abstract outlines an investigation into the development and validation of a Raman spectroscopic hand held device to determine its potential to predict meat quality of commercial lamb processed in Australia.

A Raman spectroscopic hand held device operating at 671 nM was used to measure fresh intact m. semimembranosus (SM) of 160 lambs at 25 minutes post mortem in- situ (n = 80) (Fig 1.), as well as 24 hours and 5 days post mortem (n = 160) after they were removed from the carcase in two complementary studies. Spectra were collected using 70 mW of laser power, perpendicular to the muscle fibre on a freshly cut surface of the muscle with the epimysium removed.

Ten (10) spectra for each sample were averaged and reduced to a wavenumber range between 500 – 1800 cm-1. Traits indicating meat quality were regressed against spectra using Partial Least Squares regression cross validated using Leave One Out to give a cross validated coefficient of determination (R2

cv) and the Root Mean Error of Prediction (RMSEP). The traits analysed included shear force and cooking loss [1], pH values at 24 h (pH24) and ultimate pH at 5 days [2], particle size [3], sarcomere length, purge (exudate), collagen content and colour (L*, a* and b*). Spectra for band assignments were corrected for background by fitting a 6th order polynomial.

The best prediction of shear force values at 5 days post mortem was found in the initial study using spectra collected 24 h (R2

cv = 0.27, 13% reduction in RMSEP). However the prediction of shear force was inconsistent between the two experiments as the second study demonstrated there was no ability to predict shear force. This suggests that the prediction of shear force values as an indicator of lamb tenderness does not have the repeatability required by industry.

Models for the prediction of other meat quality traits in the second study suggested that there was an ability to predict pH24 and purge using spectra measured pre-rigor (R2

cv = 0.27 and 0.32, respectively) and pHu, purge and lightness (L* values) from spectra measured at 24 h post mortem (R2

cv = 0.59, 0.42 and 0.32, respectively). Furthermore, it was possible to measure purge using spectra measured at 5 days post mortem (R2

cv = 0.33). Results of this study indicate for the first time that there is potential to predict pHu, pH24, lightness (L*), and purge

of intact lamb SM using Raman spectroscopy. While early post mortem measurements of Raman spectroscopy indicated that there is an ability to predict pH24 and purge, the most variation in these traits was described by spectra measured at 24 h post mortem.

Given the relationships between pH, purge and colour and early post mortem metabolic events [4], it is plausible that Raman spectroscopy is able to predict traits which are affected by metabolic processes or via metabolic substrates which are involved in the biochemical changes during the conversion of muscle to meat.

Indeed, tentative band assignments of spectra agree. For example the prediction of purge (R2

cv = 0.42) has associated high purge losses with a reduction in peak intensities at wavenumbers including 825 cm-1, 853 cm-1, 875 cm-1, 930 cm-1, 1044 cm-1, 1078 cm-1, 1119 cm-1, 1305 cm-1, 1335 cm-1, 1448 cm-1 and 1553 cm-1 as well as an increase in intensity for peaks between 500 – 700 cm-1(Fig 2).

Fig. 2. The averaged and background corrected spectra collected at 24 hours post mortem from the ovine m. semimembranosus with the 5 highest (4.65 – 6.42; grey) and lowest purge (1.10 – 1.23; black).

Fig. 1. Measurement of lamb m. semimembranosus in- situ at 25 m post mortem.


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Although this is the first study to predict meat quality of lamb, studies conducted early post mortem on pork indicate that these signals are related to key metabolic substrates including lactate (853 cm-1, 1042 cm-1 and 1448 cm-1), phosphate (875 cm-1 and 1078 cm-1), sugar phosphate and creatine (825 cm-1), α- helical protein (930 cm-1) and adenotriphosphate (1119 cm-1, 1305 cm-1, 1335 cm-1) [5-8]. Furthermore, increases in the intensities for peaks between 500 – 700 cm-1 represent the protein side chains, suggesting that samples with higher purge also have greater amounst of protein degradation. However, the spectral changes associated with purge in lamb are complex and not all bands can be identified by these studies on pork.

These spectral changes agree with the conclusion that the changes in Raman spectra are consistent with the relationship between water holding capacity and pH, glycogen concentration and protein conformations already established in existing literature [5, 9]. However, it is difficult to compare spectral assignments directly, as using the findings for high pHu values suggests that those samples with higher purge may have reached pHu values earlier and therefore may enter rigor at slightly higher temperatures causing greater amounts of protein degradation [10]. However, this research also suggests samples with lower pHu values may have had higher concentrations of glycogen in the muscle post mortem and therefore may have undergone anaerobic glycolysis to a greater extent in the first 24 h post mortem. This is because higher levels of inorganic phosphate [11] and lactate [12] as well as greater changes to α- helical proteins such as actin and myosin [13] and larger amounts of protein denaturation [10] have all been associated with the later stages of anaerobic glycolysis.

Although these Raman signals suggest increases in inorganic phosphate and α-helical proteins are linked to low pHu and low purge, it is unclear what exact biochemical pathways cause the relationships between these intensities and the free H+ that is measured by the pH reference measurement. Inorganic phosphate is a key element within many post mortem processes, including the breakdown of phosphocreatine, the synthesis and breakdown of glucose-6 phosphate and sugar phosphates, anaerobic glycolysis, formation and detachment of actin/myosin cross bridges and re-activation of myosin during muscular contraction [12]. Furthermore, there are many α- helical proteins present in meat including tropomyosin, myosin and actin, and the intensity of Raman signals relating to these α- helical proteins is dependent on concentration as well as sample orientation [14]. Consequently, it is difficult to determine which of these biochemical processes are vital in determining the increase in peak intensities measured in SMs.

Overall, these complementary studies demonstrate there is potential to use Raman spectra collected at 1 day post mortem to predict pHu, pH24, purge and L* measured on fresh intact lamb. Furthermore, this research indicates the potential to measure purge using Raman spectra collected at 5 days post mortem. Despite initial results suggesting there is an ability to predict shear force values, further examination indicated that this prediction was not repeatable. Comparison of the underlying spectra revealed that pHu, pH24, purge and L* predicted values were discriminated using a variety of Raman signals including those which characterise phosphate, adenotriphosphate, lactate, α – helical proteins creatine and the amino acid side chain vibrations. Consequently, these findings suggest that Raman spectroscopy has the potential to predict meat quality traits related to early post mortem metabolic processes.

Acknowledgement This work has been financially supported by the Australian Meat Processor Corporation (AMPC) and Meat and Livestock Australia (MLA), as was the senior author by scholarship. The authors also acknowledge the contribution of Matt Kerr (NSW DPI), Tracy Lamb (NSW DPI), Kristy Bailes (NSW DPI), Dr Ben Holman (NSW DPI) and Jordan Hoban (NSW DPI) who assisted in measurement of the samples. References [1] D. L. Hopkins, R. S. Hegarty, P. J. Walker, D. W. Pethick, Australian Journal of Experimental Agriculture, 46 (2006) 879-

884. [2] P. E. Bouton, F. D. Carroll, A. L. Fisher, V. Harris, W. R. Shorthose, Journal of Food Science, 38 (1973) 816-822. [3] L. U. Karumendu, R. van de Ven, M. J. Kerr, M. Lanza, D. L. Hopkins, Meat Science, 82 (2009) 425-431. [4] K. L. Pearce, K. Rosenvold, H. J. Andersen, D. L. Hopkins, Meat Science, 89 (2011) 111-124. [5] D. K. Pedersen, S. Morel, H. J. Andersen, S. Balling Engelsen, Meat Science, 65 (2003) 581-592. [6] R. Scheier, J. Köhler, H. Schmidt, Vibrational Spectroscopy, 70 (2014) 12 -17. [7] R. Scheier, H. Schmidt, Appl. Phys. B, 111 (2013) 289-297. [8] R. Scheier, M. Scheeder, H. Schmidt, Meat Science, 103 (2015) 96-103. [9] J. M. Hughes, S. K. Oiseth, P. P. Purslow, R. D. Warner, Meat Science, 98 (2014) 520-532. [10] E. Huff Lonergan, S. M. Lonergan, Meat Science, 71 (2005) 194 - 204. [11] E. M. England, T. L. Scheffler, S. C. Kasten, S. K. Matarneh, D. E. Gerrard, Meat Science, 95 (2013) 837-843. [12] M. F. W. te Pas, M. E. Everts, H. P. Haagsman, Muscle development of livestock animals- Physiology, genetics and meat

quality. (2004), Oxfordshire, United Kingdom: CABI Publishing. [13] E. Huff Lonergan, W. Zhang, S. M. Lonergan, Meat Science, 86 (2010) 184-195. [14] M. Pézolet, M. Pigeon, D. Ménard, J. P. Caillé, Biophysical Journal, 53 (1988) 319-325.


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Imaging Processed Cheese Components Using Raman Microscopy G. P. S. SMITH1, S. E. HOLROYD2 AND K. C .GORDON1

1Department of Chemistry, Dodd Walls Centre, University of Otago, Union Place West, Dunedin, 9016, New Zealand 2Fonterra Research and Development Centre, Dairy Farm Road, Palmerston North, 4472, New Zealand

Imaging microscopic objects can be a difficult task especially when they are set in landscapes which contain domains of a similar size, colour and appearance. Difficulty increases when your sample is resistant to being stained or when it reacts adversely with the colourant. When studying cheese, these problems are commonplace. An image of cheese through a light microscope could easily be mistaken for the surface of Mars, albeit with a slightly yellowish hew. Despite its initial appearance, the content of cheese can be quite diverse containing fat, protein, water, carbohydrates as well as preservatives and emulsifiers in the case of processed cheese.

Raman microscopy has proven to be an effective method for locating the majority of these components, without the use of invasive dyes or preparation methods. The purpose of this study is to determine whether Raman microscopy is an effective method for imaging the microstructure of processed cheese and whether it would also be possible to identify and locate the various additives which might be present therein. This involved collating a library of additives and obtaining their Raman spectra. These additives were then incorporated into cheese samples with concentrations as close as possible to those which might be present within processed cheese bought in stores. Imaging was initially conducted point by point (whisk-broom method) over an area of 50 x 50 µm with 400 spectral points. This low resolution method (see figure 2) was effective in finding the locales of each component within the image but the resolution could not distinguish smaller fat globules. This resulted in images where only the largest fat globules were resolved and the presence of what appeared to be fat channels. Principal component analysis was used on this data and found to be an effective method for distinguishing regions which contained the weaker additive bands, while band integrals were sufficient for separating spectra based on fat or protein content. Imaging was then performed line by line (push-broom method) which allowed many more spectral points to be collected within a relatively small time frame. Over an area of 50 x 50 µm, 22,500 spectra were collected. This provided images in which the smaller fat globules were resolved and the true crystal-like structure of the emulsifier, trisodium citrate (TSC), was observed.

Raman microscopy was effective for imaging fat, protein, water, starch and trisodium citrate. The preservative, sorbic acid, was not located -possibly because of its low concentration. Raman microscopy might therefore be able to find use for studying other food products, especially other dairy products. The ability to obtain Raman spectra of a large number of dairy product components without producing intrusive fluorescence and avoid the use of staining dyes should encourage the growth of the technique for future use in the food industry.

Fig. 1. Images of: processed cheese using a light microscope (left), fat globules inside processed cheese using a Raman microscope (middle), and an emulsifier inside processed cheese using a Raman microscope (right). Acknowledgement Thanks go to the Dodd Walls Centre for their aid in funding this project. Thanks also go to Fonterra for providing samples and lending their expertise in cheese formulation. Special thanks go to Liz Nickless for all her assistance during this research.


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Raman spectroscopy for rapid screening of nitrogen-rich adulterants in milk M. K. NIEUWOUDT1-3, S. E. HOLROYD4, C. MCGOVERIN2, M. C. SIMPSON1-3,5,6 AND D. E. WILLIAMS1-3

1MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand e-mail m.nieuwoudt@auckland,.ac,nz 2The Dodd Walls centre for Photonic and Quantum technologies, New Zealand 3School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland, 1142, New Zealand 4Fonterra Research and Development Centre, Private Bag 11029, 5The University of Auckland, 23 Symonds St., Auckland, 1142, New Zealand 6Department of Physics, The University of Auckland, 23 Symonds St., Auckland, 1142, New Zealand

Adulteration of milk for economic gain has been an issue from as early as 1857 in the form of dilution with water [1] or addition of compounds such as borax, soda or salicylic acid to increase shelf life [2]. More recently, adulteration of milk with small nitrogen-rich compounds such as melamine to fraudulently boost the apparent protein content was exposed [3]. Routine laboratory tests for these compounds by HPLC-MS require time consuming sample preparation, expensive laboratory equipment and highly skilled technicians. We investigated the feasibility of Raman spectroscopy as a rapid alternative for screening of milk for four of these nitrogen-rich contaminants: melamine, urea, dicyandiamide (DCD) and ammonium sulphate. Spectra were recorded of dried drops of milk adulterated with known concentrations of the four compounds and with different mixtures of these compounds, between 50 – 1000 ppm. No sample preparation steps such as centrifugation, filtration or addition of chemicals were necessary. Spectra were recorded using the Renishaw System 1000 microprobe with 785 nm excitation at 25 mW with total measurement time of 4 minutes for each sample. A set of spectra containing mixtures of all four compounds are shown in Fig. 1. The positions of the strongest bands for each compound are indicated by dotted lines; these overlap with the bands of the milk components. Both univariate and multivariate calibration models were determined from the spectra, using peak heights of difference bands and Partial Least Squares analysis (PLS), respectively. The limits of detection (LOD) and quantitation (LOQ) were determined for each compound from these models. LODs obtained for the univariate calibration models were 180 ppm for melamine, 230 ppm for ammonium sulphate, 130 ppm for DCD and 280 ppm for urea. The average %RSD (residual standard deviation) for three spectra of each sample was 8%. For LODs determined from the PLS calibration data the LODs were measured as a range according to an IUPAC consistent approach [4] which also takes into consideration the influence of variance of concentrations in the calibration training set. LODmin - LODmax values obtained for melamine were 100-260 ppm, for ammonium sulphate 150 – 350 ppm, for DCD 140-600 ppm and for urea 120 – 490 ppm.

Partial least squares with discriminant analysis (PLS-DA) of the spectra was used to determine the effectiveness of Raman spectroscopy to discriminate between pure and adulterated samples of milk. Using the PLS-DA on a set of 40 different samples, false positive and false negative rates of 15.4% and 0%, respectively, were obtained for screening adulterated milk samples from pure milk ones.

The results show that Raman spectroscopy enables sensitive and reproducible analysis of these compounds, with the LOD values falling within the lower range of adulteration with these compounds, estimated to be between 90 – 4000 ppm.

Substantial improvements recently in detector and laser technologies have resulted in a number of commercially available portable mini Raman spectrometers with high sensitivity, which are relatively inexpensive and are robust enough to be used on site. The performance of these for screening of milk samples adulterated with melamine, urea, DCD and ammonium sulphate was also investigated.

Acknowledgement The authors gratefully acknowledge PGP partnership funding for this project. References [1] H. Gem, Lancet (1857), Feb. 7. [2] The New York Times, Milk adulteration (1890) Aug.

13. [3] J.C. Moore, J.W. de Vries, M. Lipp, J.C. Griffiths, D.R. Abernethy, Comp. Rev. Food Sci F. (2010) 9, 330-357. [4] F. Allegrini, A.C Olivieri, Anal. Chem. (2014) 86, 7858-7866.

Fig. 1. Raman spectra of eight different milk samples adulterated with known concentrations of melamine, DCD, urea and ammonium sulphate. Peak positions of each compound are indicated with dotted lines.

ACOVS11/ASC5 Book of Abstracts Session XIII – Nanotechnology

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SESSION XIII – NANOTECHNOLOGY


123

Using Tryptophan as an in situ Fluorescent Thermometer to Quantify the Photothermal Efficiency of Gold Nanoparticles1 M.-J. CHIU1 AND L.-K. CHU1*

1Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan. e-mail: [email protected]

The photothermal effect of metallic nanoparticles upon photoexcitation, i.e., thermo-plasmonics,2 has been extensively utilized in many aspects, such as drug delivery and release,3 thermotherapeutic treatments,3 and catalysis.4 Fluorescent materials have been extensively used in determining the temperature in material and biomolecular applications.5 In this study, we have established experimental and analytical methods to illustrate the photothermal transduction efficiency of gold nanoparticles using a temperature-sensitive fluorescing molecule, tryptophan, as an molecular thermometer. The photothermal efficiencies, denoting the efficiency of transducing incident light to heat, of gold nanoparticles of different diameters (∅=22–86 nm) were quantified upon exposure at 532 nm. The fluorescence of tryptophan in 300–450 nm upon 280 nm excitation serves as a fluorescent thermometer to illustrate the evolution of the average temperature change in the heating volume of the nanoparticle solution. The fluorescence intensity decreases as the temperature increases, having a linear gradient of 2.05 % fluorescence decrease per degree Celsius increment from 20 to 45 ºC. The presence of gold nanoparticles at the nM level does not influence the temperature-dependent fluorescence of tryptophan in terms of fluorescence contour and temperature response. The heating volume was defined by overlapping the collimated 532-nm laser for exciting the nanoparticles and the 280-nm continuous-wave beam for exciting tryptophan in a 2 mm × 2 mm square tube, and the fluorescence was collected perpendicularly to the collinear alignment. This method possesses satisfactory reproducibility and sufficient temperature detectivity of 0.2 ºC. The profiles of the average temperature evolution of the mixtures containing nanoparticles and tryptophan were derived from the evolution of fluorescence and analyzed using collective energy balancing. The relative photothermal efficiencies for different sizes of gold nanoparticles with respect to the 22-nm nanoparticle agree with those predicted using Mie theory. The successful employment of tryptophan as a fluorescent thermometer not only provides an in situ tool to monitor the photothermal effect of nanostructures but is also applicable to thermal imaging in biological applications. Acknowledgement The Ministry of Science and Technology of Taiwan (MOST 103-2113-M-007-010-MY2) provided support for this research. References [1] M.-J. Chiu, L.-K. Chu, Phys. Chem. Chem. Phys. 17 (2015), 17090–17100. [2] G. Baffou, R. Quidant, Chem. Soc. Rev. 43 (2014), 3898–3907. [3] V. Shanmugam, S. Selvakumar, C.-S. Yeh, Chem. Soc. Rev. 43 (2014), 6254– 6287. [4] P. Christopher, H. Xin, S. Linic, Nature Chem. 3 (2011), 467–472. [5] J. Lee, N. A. Kotov, Nano Today 2 (2007), 48–51.

Fig 1. Schematic of the fluorescent thermometer using tryptophan upon excitation of gold nanoparticles.


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Insight into CMOS-MEMS device using Energy Dispersive X-Ray Spectroscopy M. A. KHAN1 AND R.K. ZHENG2 1School of Physics, The University of Sydney, 2006, NSW, Australia [email protected] 2School of Physics, The University of Sydney, 2006, NSW, Australia

Micro-Electrical-Mechanical Systems or MEMS is a technology in which electrical and mechanical components are embedded on a microchip. MEMS components (sensors or actuators) are appropriately categorized as “transducers”, which are defined as miniaturized devices that convert energy from one form to another, as depicted in Figure.1a. MEMS devices are widely used in all areas of industrial automobile (air-bags), avionics (gyroscope), health care (BioMEMS), microscopy product (AFM), mobile (accelerometer) and wireless applications (RF tuners) due to their low-cost and small-size [1, 2].

In parallel, complementary metal–oxide–semiconductor or CMOS is also the dominant semiconductor technology for microprocessors, microcontrollers, memories and application specific integrated circuits (ASICs). The main advantage of the CMOS over NMOS (n-type of CMOS) and bipolar technology (TTL: transistor-transistor logic) is its much smaller power dissipation [3]. Nowadays, the power of the CMOS technology is not only exploited for ICs, but also for a variety of micro sensors and micro machines systems (MEMS). The need of “Everything on Single IC” is required, because MEMS and electronic circuits on separate chips have parasitic capacitance, and resistance of interconnects, bond pads and bond wires can attenuate the signal and contribute to the significant noise in a device [4, 5]. The decision to merge CMOS (electronic) and MEMS (non-electronic) devices is mainly driven by performance of CMOS, size and cost of the MEMS. The advantage of micro machined devices fabricated by the CMOS-MEMS technique is the compatibility with the CMOS process, and thus devices can easy integrate with other electronics circuits on single chip.

Basis on this conference proposal, we will attempt to present a perspective on the monolithic integration of the CMOS-MEMS technology. In order to realize a given MEMS-based product, a digital microphone (courtesy of Akustica Inc.) will be analysed under the one of the powerful microscopic tool of Energy Dispersive X-Ray Spectroscopy (EDS) [6, 7]. In digital microphone, MEMS membrane acts as capacitive acoustic sensor (sound radiation), while the CMOS performs electronic operations. EDS or XEDS using the principle of X-ray performs qualitative and quantitative analysis on integrated CMOS-MEMS-based microchip. Further, microanalytical X-Ray technique along with EBSD-TKD has been applied on bulk and FIB prepared thin (TEM) samples of digital microphone. This analysis helps us to investigate the chemical composition, metal interface boundaries, sensor parasitic and non-parasitic capacitive setup, grain structures and phases exists in between CMOS and MEMS junctions (Figure.1b)

In this context, motivation is to highlight the basics of the CMOS-MEMS technology, its monolithic integration, and optimization in its fabrication approach. Particularly, focus of this report is to present a competitive analysis performed by EDS+EBSD technique on real-life application product (digital microphone). Further, the goal is to figure out possible solutions to design efficient and low-cost CMOS-MEMS technology. Acknowledgement The authors acknowledge the facilities, scientific and technical assistance of the Australian Microscopy & Microanalysis Research Facility (AMMRF) provided by Australian Centre for Microscopy & Microanalysis (ACMM) at the University of Sydney. References [1] K. J. Gabriel, Microelectromechanical systems. Proceedings of the IEEE. 86 (1998), 1534-1535. [2] T. F. Marinis, The Future of Microelectromechanical systems (MEMS). Strain. 45 (2009), 208–220. [3] H. Baltes, O. Brand, G. K. Fedder, C. Hierold, J. Korvink, O. Tabata, Advanced Micro and Nanosystem; Vol. 2. CMOS-MEMS,

Wiley-VCH: Weinheim (2005), 2-27. [4] A. Witvrouw, IEEE/ACM Intl. Conf. on Computer-Aided Design: San Jose, CA (2006), 826-827. [5] C. Liu, Foundations of MEMS; 2nd Eds., Person Education: USA (2012), 530–532. [6] Akustica Inc., http://www.akustica.com/aku230. [7] P.W. Trimby, Ultramicroscopy 120 (2012), 16-24.

Fig. 1. (a) MEMS components and (b) SEM image of MEMS-based digital microphone.


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Surface Enhanced Raman Spectroscopy on Metal Nitride Thin Films S. L. ZHU1, L. XIAO1 AND M. CORTIE1

1Institute for Nanoscale Technology, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia [email protected]

Raman spectroscopy is a useful technique for providing information on the structure of molecules and solid surfaces [1]. The Raman signal can be enhanced if the analyte is located within an enhanced electromagnetic field generated by a plasmon resonance. This amplification effect is known as Surface Enhanced Raman Spectroscopy (SERS) [2]. In this paper, we explore SERS on titanium-aluminium nitride, TiN and (Ti,Al)N, thin films produced by physical vapour deposition under vacuum. Titanium nitride has the necessary dielectric function to support localised plasmon resonances [3] but is rarely applied for this purpose. The films are compared at the same thickness (30 nm). Rhodamine 6G (R6G) is used as the Raman probe molecule.

Raman spectra of TiN and TiAlN thin films with R6G (0.02 mg/ml) are shown in Fig. 1. The wavelength of laser is 633 nm. Laser power is 0.5 mW (5% of the full laser power of 10 mW). The substrate is glass. Fig. 1 shows that the Raman spectra of R6G on TiN and TiAlN thin films are enhanced compared to the signal on a bare glass slide with R6G. The mechanism of Raman enhancement is presumably the plasmonic response of the TiN. These films could be used as substrates in Raman-based sensors in the future. Acknowledgement We thank Geoff McCredie for assistance with the deposition. This work is supported by ARC Discovery project (120102545). References [1] D. J. Gardiner, Practical Raman spectroscopy, Springer-Verlag. [2] S. Nie, S. R. Emory, Science, 275 (1997), 1102–1106. [3] M. B. Cortie, J. Giddings & A. Dowd, Nanotechnology, 21 (2010), article 115201.

Fig. 1. Raman spectra of bare glass, TiN and TiAlN (vertically offset by 500 and 1000 counts) thin films with R6G.


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Latest development in Nano-Raman Spectroscopy and application to materials analysis. R. BENFERHAT

HORIBA INSTRUMENTS (SINGAPORE) PTE LTD, 3 Changi Business Park Vista, #01-01, Singapore [email protected]

Raman spectroscopy is a spectroscopic technique used to study vibrational, rotational, and other low-frequency modes of a sample.

Raman spectroscopy is commonly used in many different application field as it therefore provides a fingerprint by which molecules can be identified. When coupled to a microscope, the technique offers several advantages for microscopic analysis, as information can be collected from very small volumes (< 1 µm in diameter).

Recently, with the growing attraction of the nanotechnologies, due to their application in many field, the development of Nano-Raman attracted many scientist. In this presentation, we will introduce the latest development in Nano-Raman and their application for the nano examination of materials in different field like semiconductors and nanotechnology.


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Surface Enhanced Raman Scattering Based Sensors for Small Molecules I. BLAKEY1*, P. DENMAN1, M. SIAUW1 AND K. JACK1

1The University of Queensland, St Lucia, 4072 Australia, [email protected]

Sensors pervade our lives in an ever-increasing number of devices, with chemical sensors being used in a diverse range of sectors that include: security- explosives or drug detection; environmental monitoring- detection of pollutants; energy- monitoring of emissions; home- detection of toxins; healthcare- detection of disease markers or metabolites. Traditionally, Raman spectrometers have been bulky and expensive. However, strong advances in the development of lasers, charged-coupled-device (CCD) detectors, computers and software have reached the stage where bench top instruments are increasingly affordable and easy to use. In addition, hand-held instruments are now commercially available. Further technological advances, minaturaisation [1] and cost reduction will make wider adoption of Raman based sensors in everyday devices a real possibility.

Raman spectroscopy has a number of advantages as a chemical sensing modality, which include high information content and in the case of Surface Enhanced Raman Spectroscopy (SERS) the potential of single molecule sensitivity. However, the vast majority of reports on SERS as a sensing modality rely on direct detection of analytes that adsorb to a nanostructured substrate [2]. Hence, selectivity of analysis can be poor and complex mixtures can be problematic if other molecules in the mixture give rise to overlapping signals or preferentially adsorb to the subtrate. An additional issue is some analytes of interest have a low or non-existent Raman scattering cross section or do not bind to the SERS substrate, so can not be detected.

In this presentation the development of SERS based sensors for detecting small molecules, in particular hydrogen peroxide will be discussed. Reactive oxygen species such as hydrogen peroxide are constantly formed in the human body as a part of normal metabolic processes and normal concentrations have been implicated in cell signalling functions, but elevated concentrations of ROS have been implicated in a range of adverse health such as aging, ischemia, inflammatory and autoimmune diseases, as well as atherosclerosis.

We have prepared aggregates of gold nanoparticles that have been functionalised with a molecule that selectively reacts with hydrogen peroxide. Before reaction the molecule has a distinctive Raman spectrum, which then changes as a result of structural changes in the molecule during reaction (See Fig 1 a). This gives a ratiometric response which allows the kinetics of the reaction to be followed in real time. An example of this is shown in Fig 1 b) which shows the kinetic curves for a control, 20 uM and 200 uM, where the latter two concentrations relate to physiological and oxidative stress respectively. References [1] Malinen, J.; Rissanen, A.; Saari, H.; Karioja, P.; Karppinen, M.; Aalto, T.; Tukkiniemi, K., Proc. SPIE 9101 (2014), 91010C. [2] Sharma, B.; Frontiera, R. R.; Henry, A.-I.; Ringe, E.; Van Duyne, R. P., Materials Today 15 (2012), 16-25.

Fig. 1. a) Time resolved spectra for the detection of hydrogen peroxide. b) Comparison of the kinetic curves for the control, 20 µM and 200 µM sensing of hydrogen peroxide.

ACOVS11/ASC5 Book of Abstracts Session XIV – Biospectroscopy III

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SESSION XIV – BIOSPECTROSCOPY III


129

Raman optical activity: Biospectroscopy with a twist E. W. BLANCH

School of Applied Sciences, RMIT University, GPO Box 2476, Melbourne VIC 3001, Australia, [email protected]

Raman optical activity (ROA) measures the small difference in Raman scattering from chiral molecules using right- and left-circularly polarized light, and combines the high information content of Raman spectroscopy with the high sensitivity to stereochemistry of circular dichroism. As a result, has become a powerful probe of the conformation and behaviour of a wide range of biological molecules. This talk will present an introduction to ROA spectroscopy and then profile results from a number of studies to illustrate the ability of ROA to provide detailed and novel information on complex biological systems. These include both experimental and quantum mechanics/molecular dynamics investigations into:

i) natural product characterization, ii) protein misfolding and stability, and iii) carbohydrate structure and the role of solvation in the conformational dynamics of sugars.

References [1] Monteiro, A.F., Batista, J.M., Machado, M.A., Severino, R.P., Blanch, E.W., Bolzani, V.S., Vieira, P.C. and Severino, V.G.P. Journal of Natural Products (2015), 78, 1451-1455. [2] Batista, A.N.L., Batista Jr., J.M., Bolzani, V.S., Furlan, M. and Blanch, E.W. Physical Chemistry Chemical Physics (2013), 15, 20147-20152 [3] Batista, A.N.L., Batista Jr., J.M., Ashton, L., Bolzani, V.S., Furlan, M. and Blanch, E.W. Chirality (2014) in press. [4] Mutter, S.T., Zielinski, F., Cheeseman, J.R., Johannessen, C., Popelier, P.L.A. and Blanch, E.W. Physical Chemistry Chemical Physics (2015), 17, 6016-6027. [5] Zielinski, F., Mutter, S.T., Johannessen, C., Blanch, E.W. and Popelier, P.L.A. Physical Chemistry Chemical Physics (2015), accepted. [6] Ashton, L.A., Pudney, P.D.A., Blanch, E.W. and Yakubov, G.A. Advances in Colloid and Interface Science (2013), 199, 66-77.


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Molecular Mechanisms of Cytochrome c Oxidase as Studied by Vibrational Spectroscopy T. OGURA1*, S. NAKASHIMA1, K. SHINZAWA-ITOH1 AND S. YOSHIKAWA1

1Picobiology Institute, Grad. Schl. Life Sci., University of Hyogo, RSC-UH Leading Program Center, Koto 1-1-1, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan [email protected]

In the mitochondrial respiratory chain, three membrane protein complexes couple electron transfer with proton pumping. The proton motive force thus generated across the inner mitochondrial membrane is utilized to synthesize ATP, the energy currency of the cell. Dietary allowance for a 60 kg weight adult is 8000 kJ per day, which corresponds to 200 moles of ATP. Since human body contains only 0.1 moles of total adenine nucleotide, regeneration of ATP by 2000 times per day is required. The regeneration of ATP from ADP is performed on the inner mitochondrial membrane.

Cytochrome c oxidase (CcO) is one of the above three protein complexes and reduces dioxygen to water. The dioxygen reduction by CcO is coupled with proton pumping. X-ray crystallography has determined the three dimensional structures for distinct oxidation and ligation states of the bovine enzyme at a resolution as high as 1.8 Å [1]. Vibrational spectroscopy, on the other hand, has revealed the electronic state difference of functional groups in the protein and also provided information with regard to the protein dynamics. Actually, time-resolved resonance Raman (RR) spectroscopy has been applied to determine the heme coordination geometry of the reaction intermediates during dioxygen reduction, and to probe the protein dynamics after ligand dissociation from the heme. This is based on the high selectivity of RR spectroscopy to the heme and its vicinity. Application of RR spectroscopy even to whole mitochondria was successful, in which a Raman band originating from a single chemical bond was detected [2].

A high-sensitivity infrared spectrophotometer developed in our laboratory has enabled us to study dynamics of the metal sites and protein main chain after ligand dissociation [3]. The infrared spectrophotometer is able to detect an absorbance change as small as 0.03 mOD on an absorption background of 2 and has a time resolution of 50 ns. In the experiments, temporal change of amide I band region assignable to a few main chain C=O of the protein was detected out of 1800 amino acids in bovine CcO. Based on the results, we propose a presence of “an information relay system” between the dioxygen reducing site and proton gate site in CcO, by which an efficient proton pumping is realized [4]. Acknowledgement We acknowledge Mr. T. Nishiguchi and Ms. Chen Li of University of Hyogo for collaboration. References [1] K. Muramoto, K. Ohta, Kyoko Shinzawa-Itoh, K. Kanda, M. Taniguchi, H. Nabekura, E. Yamashita, T. Tsukihara, and S.

Yoshikawa, Proc. Natl. Acad. Sci. USA 77 (2010), 7740–7745. [2] T. Ogura, Biochim. Biophys. Acta 1817 (2012), 575–578. [3] M. Kubo, S. Nakashima, S. Yamaguchi, T. Ogura, M. Mochizuki, J. Kang, M. Tateno, and S. Yoshikawa J. Biol. Chem. 288

(2013), 30259–30269. [4] S. Nakashima, T. Ogura, and T. Kitagawa, Biochim. Biophys. Acta 1847 (2015), 86–97.


131

Characterisation of the molecular composition and impact of stresses on microencapsulated Lactobacillus rhamnosus GG using Raman spectroscopy M. M. HLAING1, B. R. WOOD2, D. MCNAUGHTON2, D. Y. YING1, M. A. AUGUSTIN1 1CSIRO Breakthrough Bioprocessing, Food and Nutrition, 671 Sneydes Road, Werribee, Victoria 3030, Australia e [email protected] 2Centre for Biospectroscopy, School of Chemistry, Monash University, Victoria 3800, Australia

Freezing and dehydration expose bacterial cells to stresses such as extremes of cold temperature, oxygen and osmotic changes, all of which may impair cell survival. Microencapsulation technology, which is a process to entrap probiotic bacterial cells within a matrix, has been developed to keep the cells viable and stable throughout the production of probiotics. In this study, the application of confocal Raman spectroscopy for examining the chemical composition of non-encapsulated and microencapsulated bacterial cells on dehydration and upon rehydration was investigated.

The results show that freeze drying had detrimental effects on bacterial cells, as evidenced by changes in the spectral features associated with various biochemical compounds found in bacterial cells. Analysis based on Principal Components Analysis (PCA) suggests that microencapsulation protects cells from environmental stress. The results also reveal a B- to A-like DNA conformation change in dormant microencapsulated cells and the reversibility of this transition upon rehydration. The extent of this reversibility is less in non-encapsulated than in microencapsulated cells. These findings have demonstrated the effectiveness of Raman spectroscopy as a tool to identify the reversibility of DNA conformational changes in microencapsulated bacterial cells, which are not detectable using conventional cell viability assays. The intensity fluctuations of the peaks corresponding to the phosphodiester bands in DNA backbone regions indicate a series of potential Raman markers that can be used in rapid sensing of microbial stress responses. References [1] M. Brennan, B. Wanismail, M. C. Johnson, J. Food Prot. 49 (1986), 47-53. [2] M. van de Guchte, P. Serror, C. Chervaux, T. Smokvina, S. D. Ehrlich, E. Maguin, Anton. Leeuw. Int. J. G. 82 (2002), 187-216. [3] J. Burgain, C. Gaiani, M. Linder, J. Scher, J. Food Eng. 104 (2011), 467-483.


132

DNA conformation and nuclear ultrastructure analysed with synchrotron FTIR, Soft X-ray Tomography, NanoIR and TERS B. R. WOOD1*, E. LIPEC1,2, P. HERAUD1, D. WHELAN1, D. MCNAUGHTON, J. ZHANG3, D. Y. PARKINSON3, J. BIELECKI2

W. M. KWIATEK2, M. LEKKA2, M. J. TOBIN4, K. R. BAMBERY4, C. B. ADIBA5, G. DIETLER5, A. KULIK5, A. JAPARDIZE5, F. S. RUGGERI5

1Centre for Biospectroscopy, School of Chemistry, Monash University, 3800, Victoria, Australia, [email protected] 2 Institute of Nuclear Physics Polish Academy of Sciences, PAN, 31-342 Kraków, Poland 3Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California, 94720, United States 4Australian Synchrotron, 800 Blackburn Rd Clayton, Victoria 3168, Australia 5EPFL, Rte de la Sorge, CH-1015 Lausanne, Switzerland

The combination of synchrotron Fourier transform infrared (SFTIR) spectroscopy, synchrotron radiation X-ray tomographic microscopy (SRXTM), nanoIR and Tip Enhanced Raman Scattering (TERS) was used to investigate the DNA conformation and ultrafine structure in the nucleus of avian erythrocytes fixed and under physiological conditions. We have recently shown using SFTIR that upon desiccation the DNA in eukaryotic cells changes from the B-DNA conformation to the A-DNA conformation and in the case of air-drying this conformation can be reversed. Interestingly upon the B-DNA to A-DNA conformational a change in the intensity of the symmetric stretching phosphodiester backbone vibration of DNA at ~1080 cm-1 dramatically diminishes and the band assigned to the asymmetric phosphodiester mode shifts from ~1220 cm-1 to 1240 cm-1.[1] The change in intensity of the symmetric phosphodiester vibration is due to change in the molar extinction coefficient going from the more ordered B-DNA form where the dipole moments are more aligned to the narrow and disordered A-DNA form where the dipole moments associated with the phosphodiester groups are less aligned. The integrated intensity of the symmetric phosphodiester band can be used to quantify the amount of DNA at the single cell level[2] and can also be used to follow the progression of the cell cycle.[3] While this reversible DNA conformation appears to have no biological relevance in eukaryotic cells the conformation may play an important protective role of the DNA in certain prokaryotes and other desiccant tolerant organisms.

In another study we applied and developed Infrared nano-spectroscopy (nanoIR) to explore the detailed composition of chromosomes. NanoIR coupled with Principal Component Analysis (PCA) has confirmed that chromosome areas containing eu- and heterochromatin are distinguishable based on their chemical composition. Here a new methodology is presented that enables the detection of DNA methylation in human chromosomes providing the spatial location of the heterochromatin–euchromatin boundary at a spatial resolution below 100 nm.

SRXTM utilizes a synchrotron X-ray source, which provides a brilliant and intense X-ray beam. The high X-ray brilliance enables high-resolution 3D imaging of single cell resulting in low-noise data with optimal contrast approaching 50 nm spatial resolution.[5] The specimen in SXT is illuminated using photons with energies that in water window region of the electromagnetic spectrum. The attenuation of these photons follows the Beer–Lambert Law, and is therefore linear, quantitative and dependent on chemical species and thickness.[5] Carbon and nitrogen — major constituents of DNA and protein —attenuate the transmission of X-rays an order of magnitude more strongly than water.[5] We have investigated the interphase nucleus of an avian erythrocyte in isotonic saline and after 4% formalin fixation to investigate the ultrastructure of histone packing. The 3D movies of the cell in isotonic saline (Figure 1A) shows a very spherical nucleus with clusters of chromosomal material linked through an intricate 3D network of tubular structures of various diameters. After fixation (Figure 1B) the nucleus is elliptical and the nuclear material appears more dispersed accumulating around the nuclear envelope. The movies demonstrate the dramatic effects fixative has on the nuclear structure of cells and more importantly shows the nuclear ultrastructure to be a network of integrated clusters of nuclear material linked together by thread like structures of various diameters. The work demonstrates how a combination of synchrotron-based techniques, nanoIR and TERS can be used to obtain information on both the ultrafine structural architecture of the nuclear material and the molecular conformation of DNA under various environmental conditions. Acknowledgement The authors wish to acknowledge the Australian Synchrotron (Melbourne) for the provision of synchrotron beamtime through their merit-based access program. References [[1] D. R. Whelan, K. R. Bambery, P. Heraud, M. J. Tobin, M. Diem, D. McNaughton, B. R. Wood, Nucleic acids research 2011, 39, 5439-5448. [2] D. R. Whelan, K. R. Bambery, L. Puskar, D. McNaughton, B. R. Wood, Journal of biophotonics 2013, 6, 775-784. [3] D. R. Whelan, K. R. Bambery, L. Puskar, D. McNaughton, B. R. Wood, Analyst 2013, 138, 3891-3899. [4] D. R. Whelan, T. J. Hiscox, J. I. Rood, K. R. Bambery, D. McNaughton, B. R. Wood, Journal of The Royal Society Interface 2014, 11, 20140454. [5] D. Y. Parkinson, L. R. Epperly, G. McDermott, M. A. Le Gros, R. M. Boudreau, C. A. Larabell, in Nanoimaging: Methods and Protocols, Vol. 950 (Eds.: A. A. Sousa, M. J. Kruhlak), Springer Science+Business Media, New York, 2013, pp. 457-481.

ACOVS11/ASC5 Book of Abstracts Session XV – Minerology/Gemmology

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SESSION XV - MINEROLOGY/GEMMOLOGY


134

Raman Mapping of Molybdenite in Graphitic Metasediments S. SHARMA1, T. RODEMANN2*, G. DAVIDSON1 AND D. R. COOKE1

1ARC Centre of Excellence in Ore Deposits, University of Tasmania, Private Bag 79, Hobart, 7001, TAS, Australia 2Central Science Laboratory, University of Tasmania, Private Bag 74, Hobart, 7001, TAS, Australia, [email protected]

One of the world’s highest grade molybdenum-rhenium (Mo-Re) deposits is Merlin which is located in Mount Isa, Queensland, Australia. The Molybdenite is primarily hosted by Mesoproterozoic graphitic metasediments and has a published resource of 6.4 Mt with 1.5% Mo and 18g/t Re1.

Molybdenite (MoS2) and graphite (C) are intimately associated in the ore zones: graphite occurs as fragments within the ore, as well as around the ore margins, where it can form discrete shear zones. Raman microspectroscopy has facilitated the characterisation of graphite within the Merlin ore, and provides information on its deportment and genetic implications. Graphite constitutes up to 10 wt. % of Merlin ore, and is lowest (0.01 wt. %) in silicified host rock. Raman mapping demonstrates that graphite at Merlin (typically as ~50 × ~500 µm blades) is closely intergrown with molybdenite (200 × 500 µm), and is present along the boundaries of molybdenite grains. Graphite crystallographically ranges from poorly formed in adjacent silicified rock units to well crystallised in the host rock, i.e. carbonaceous slate. Merlin molybdenite has previously been shown2 to occur in two main forms: ‘dirty’ inclusion-rich anhedral grains (molybdenite 1), and coarser, euhedral, inclusion-free grains (molybdenite 2). The two forms of molybdenite also have differences in trace element composition2. Raman spectroscopy presented here demonstrates that molybdenite 1 & 2 also have different spectral features and the distribution can be imaged which also shows the presence of graphite micron-scale inclusions in molybdenite 1 (Fig. 1), indicating that the two different types of molybdenite formed at separate times under differing physicochemical conditions. Graphite may have provided additional ductility and alternative paths for strain partitioning during ore formation, because in several places mylonitic graphite shears cut the brecciated ore body. The presence of molybdenite and graphite together produced very ductile fabrics, as well as sharp faults and breccia.

Sample preparation for high spatial resolution Raman mapping of these samples has proven to be difficult due to the layered structure of both molybdenite and graphite which makes it difficult to produce a smooth polished surface. Graphite however is a challenging component to map by Raman as variation in laser focus results in variation of laser power at the sample surface which in turn influences the peak shift and width of the first order Raman peaks of graphite3. Autofocus measurements are needed to ensure that laser focus is always at the sample surface, especially when using a high magnification (100× ) for high spatial resolution maps.

Fig. 1. Raman image (532nm, 1800 l/mm, 100× objective (0.85 NA), 103× 87 pixels with 0.5 µm step) showing the different regions of molybdenite, dark blue regions represent an upfield shift of about 1-1.5 cm-1 of the molybdenite Raman shifts and are considered to be molybdenite 1, the lighter blue region representing molybdenite 2. The red regions show amorphous graphite micron-scale inclusions within the molybdenite 1. Acknowledgement We acknowledge Chinova Resources Pty Ltd for some of the research funding. References [1] Chinova Resources Pty Ltd, (2014), online available at: http://www.chinovaresources.com/. [Accessed 17 July 2015] [2] P. G. Kirkby, Characteristics and origin of IOCG - Associated Mo-Re mineralisation in the Merlin deposit, Mt Isa Inlier: Unpub.

Honours thesis, University of Tasmania (2009). [3] S. Reich, C. Thomsen, Phil. Trans. R. Soc. Lond. A, 362 (2004), 2271-2288.


135

Tracing exchange vectors of minerals in hydrothermal systems using SWIR and TIR active functional groups C. LAUKAMP1*, I.C. LAU1 AND R. WANG1 1CSIRO Mineral Resources, Dick Perry Avenue 26, Kensington, 6151, WA, Australia [email protected]

Reflectance spectroscopy is increasingly used in the resources sector as a tool for green fields and brown fields exploration as well as resource characterisation. Two of the main objectives are 1) mapping mineral assemblages that help to define the respective mineral system and 2) tracing exchange vectors that provide insights into the chemical composition of alteration minerals. Both objectives assist in vectoring towards the ore in hydrothermal systems. The shortwave (SWIR; 1000 to 2500 nm) and thermal infrared (TIR; 6500 to 14500 nm) represent wavelength regions of special interest, as they allow the characterisation of major rock forming and alteration minerals and their respective compositional variations, mainly based on mapping of hydroxyl- and Si-O related functional groups.

This paper aims to review exchange vectors of example minerals, such as white micas, sulphates and garnets. These minerals are important for understanding the architecture and potentially the genesis of hydrothermal systems, such as epithermal, porphyry, skarn or orogenic gold systems. Furthermore, the potential of commercially available hyperspectral remote and proximal sensing systems for tracing the respective infrared functional groups is discussed in the frame of geological case studies.

White micas are common indicators for hydrothermal alteration processes in numerous mineral systems. In porphyry systems for example, white mica can form via hydrolytic alteration of feldspar (so called “phyllic alteration”) initially between 300 to 550°C above the higher T potassic alteration zone (i.e. dark micas and K-feldspar) and below the advanced argillic alteration zone (i.e. alunite ± pyrophyllite ± dickite/kaolinite), reflecting an upwards decreasing T and pH gradient. However, the collapse of the hydrothermal system or several pulses of intrusion-related fluids can lead to a superposition of white mica alteration on earlier formed potassic alteration [1]. In the volcanic hosted massive sulphide (VHMS) system of Panorama (Western Australia) white micas formed as result of upwelling hydrothermal fluids at temperatures of 175 to 325°C [2]. Compositional zoning of white micas in hydrothermal deposits is manifested in a change of the Tschermak composition (AlIVAlVISiIV

-1(Fe,Mg)VI-1) [3], which impacts on the wavelength position of

a major SWIR absorption feature at around 2200 nm. This absorption feature is due to the combination of the hydroxyl-related stretching and bending fundamentals and can be tracked with hyperspectral remote and proximal sensing technologies. Observed trends range from distal high-Al/low-Si micas (e.g. muscovite; short wavelength) to low-Al/high-Si micas (e.g. phengite; long wavelength) proximal to the ore (e.g. Kanowna Belle, WA) or distal to the ore (e.g. Ann Mason porphyry Cu-Mo deposit [4]). Numerous reasons for the zoning of white micas in different hydrothermal systems are discussed in literature, such as pH and concentration of ferrous iron and potassium in the hydrothermal fluids (Porphyry Cu [4]; VHMS [2]) or temperature (e.g. muscovite = low-T recharge zones vs. phengite = high-T hydrothermal fluids).

Alunites of various elemental substitutions form a major sulphate mineral group that is relevant to hydrothermal systems. The general formula of the alunite group is AB3+

3(TO4)2(OH)6, where A may be occupied by K, Na, H3O, NH4, Ag, Pb, Ca and Ba. The B site is occupied by Al, Fe3+ or Cu, and T is mainly occupied by S but P, As, V and Si may occur [5]. For alunite, replacement of K by Na may occur up to Na/K ratios of 9:2 [5]. Alunite is formed by the action of H2SO4, derived from the oxidation of pyrite and other sulphides, on nearby rocks, where ‘alunitization’ is usually accompanied by kaolinization and silicification [5]. An increasing Na-content in alunites was attributed to increasing temperature of formation. A complete solid solution was demonstrated between alunite and natro-alunite for temperatures in the range of 350–450°C though a solvus was suggested to extend to as low as 250°C [6]. An increasing Na/K ratio in alunite causes a shift of the hydroxyl-related overtone in alunite at around 1480 nm to longer wavelengths [7]. A shift of the same absorption feature to longer wavelengths in alunites was identified by [8] towards the intrusive centre of the Mankayan Cu-Au district, Luzon, Philippines using a field spectroradiometer, which was interpreted as increasing Na/K ratio and therefore increasing temperature. On the base of drill core hyperspectral data, changes in the Na/K ratio of alunites were also observed in other mineral systems, such as in the sediment-hosted Au deposit at Mt Olympus (Capricorn Orogen, Western Australia), where these gradients are probably characteristic for the larger-scale alteration footprint and therefore important for exploration.

Garnets are common components of skarn-related alteration with a wide variety of compositions across endo- and exoskarns. For example, in the skarn-hosted Cu-Zn-Mo deposit of Antamina (Peru) grossular ± andradite were described as the major garnet phases in endoskarn whereas the exoskarn was dominated by andradite ± uvarovite. Using hyperspectral TIR data collected from drill core samples with a HyLogging system, a shift of the garnet-related SiO4 tetrahedra stretching modes between 10000 and 12000 nm towards shorter wavelengths with increasing grossular component of the ugrandite series (i.e. increasing Al/Fe, cf. [9]) could be observed [10]. Tracking the compositional changes of the garnets helped to distinguish the Cu-Zn from the Mo-dominated parts of the ore body. At the Cu-skarn and Cu-porphyry deposits at Yerington (Nevada), mineralogical vectors towards the deposits were mapped using TIR airborne hyperspectral data [11]. Compositional changes were recorded in the garnet and feldspar chemistry respectively, with andradites occurring proximal to the Cu-skarn deposit at Yerington.

The examples presented here are just a small excerpt of the full variability of chemical gradients that are captured by alteration minerals in hydrothermal systems. Hyperspectral proximal and remote sensing technologies, such as hyperspectral drill core scanners or airborne systems enable geologists to identify the respective compositional changes and use them, for example, 1) as vectors towards potential mineralisation during exploration, 2) for advanced resource characterisation, and 3) to better understand the evolution of the different mineral systems.


136

References [1] L.B. Gustafson, J.P. Hunt, Econ. Geol. 70 (1975), 857–912. [2] F.J.A. Van Ruitenbeek, T.J. Cudahy, F.D. van der Meer, M. Hale, Ore Geol. Rev. 45 (2012), 33−46. [3] E.F. Duke, Geology. 22 (1994), 621–624. [4] S. Halley, J.H. Dilles, R.M. Tosdal, SEG Newsletter 100 (2015), 1–29. [5] R.V. Gaines, H.C.W. Skinner, E.E. Ford, B. Mason, A. Rosenzweig, Dana's New Mineralogy: John Wiley & Sons, New York,

(1997). [6] R.E. Stoffregen, G.L. Cygan, Am. Min. 75 (1990), 209−220. [7] J.L. Bishop, E. Murad, Am. Min. 90 (2005), 1100–1107. [8] Z.S. Chang, J.W. Hedenquist, N.C. White, D.R. Cooke, M. Roach, C. Deyell, J. Garicia Jr, J.B. Gemmell, S. McJnight, A.L.

Cuison, Econ. Geol. 106 (2011), 1365−1398. [9] C.A. Geiger, B. Winkler, K. Langer, Min. Mag. 53 (1989), 231−237. [10] C. Laukamp, S. Windle, K. Yang, C. Cudahy, I. Lau, AESC 2014 (2014), 273−274. [11] T.J. Cudahy, J. Wilson, R.D. Hewson, K. Okada, P. Linton, P. Harris, M. Sears, J.A. Hackwell, IEEE International Conference

on Geoscience and Remote Sensing, Sydney, Australia (2001).


137

Raman Spectroscopic Characterisation of Al/Mg-Chromite Oxidation in New Caledonian Ni laterite M. A. WELLS1*, E. R. RAMANAIDOU1 AND J. BOURDET1

1CSIRO, 26 Dick Perry Ave., Kensington, Perth, 6151, Western Australia, Australia [email protected]

Oxide type or ‘limonitic’ style lateritic nickel deposits, characterised by goethite, α-FeO.OH, as the main host of Ni [1], as typified by the Goro Ni deposit on the southern New Caledonian mainland, are an important source of Ni and typically show a global average Ni grade of 1.0–1.6 wt% Ni [2]. Locally, such deposits, may also show elevated contents to several wt% of other elements, such as Cr, which may occur either through residual or absolute accumulation in the weathering profile. Generally considered a resistate phase within weathering profiles, the presence of micro-morphological features arising from localised dissolution coupled with compositional zonation detected by electron microprobe analysis (EMPA) of Al/Mg-chromite grains from the oxide zone of the Goro lateritic Ni deposit provided evidence for the leaching and mobility of Cr during laterite formation. Dissolution features were previously noted, for example, in Cr-spinels from chromitic sands [3]. However, the mineralogical changes associated with changes in spinel-chromite composition have been less well characterised. As a means of understanding better the changes in mineralogy of Cr-bearing spinels associated with compositional changes as mapped by EPM analysis, Raman spectroscopic analysis was used to characterise, in situ, the mineralogy of Cr-spinel grains within the oxide or ‘yellow laterite’ zone of the Goro Ni deposit.

Aluminium/Mg-bearing chromite (spinel-chromite solid solution) was identified in the ‘yellow laterite’ zone in drill core over the interval 19.9–35.7 m, where the bulk Cr2O3 content averaged 2.73 wt%. For oxidised grains of Al/Mg-chromite (Fig. 1), Raman spot measurements were collected across an oxidising front identified in the Al/Mg-grain by EMPA (Fig. 2).

For unoxidised spinel-chromite with a composition of ≈40 wt% Cr, ≈32 wt% Fe, ≈2 wt % Al and neglible MgO, two strong peaks at 547 and 676 cm-1 were detected (Site 2, Fig. 2) with the strongest peak assigned to the A1g mode, consistent with the vibrational modes expected for spinel group minerals [4]. Other peaks in minerals of the spinel group, such as the peak at 547 cm-1 and the small shoulder at about 630 cm-1 (Fig. 2) belong to Eg and F2g symmetries [4].

As oxidation proceeds, associated with the removal of Cr, Al and Mg and a significant increase in Fe content, Raman shifts of the peaks detected were consistent with the formation of near-stoichiometric hematite, α-Fe2O3, (Sites 5 and 7, Fig. 2) [5]. The strong peak at 547 cm-

1 in the spinel-chromite completely disappeared and minor peaks consistent with the formation of hematite were detected for Site 5 (Fig. 2). Near complete oxidation of spinel-chromite and formation of hematite occurred over a comparatively short distance of the order of 2–3 µm.

Hence, as well as demonstrating the comparative instability of spinel-chromite solid solution minerals, these phases may also act as a potential source of not only Cr, but also of Al and Mg during the later stage, geochemical evolution of lateritic nickel deposits.

Acknowledgement The authors would like to acknowledge the anonymous reviewer (CSIRO) for their comments in improving an earlier draft of this abstract. References [1] M. A. Wells, E. R. Ramanaidou, M. Verrall, C. Tessarolo, Eur. J. Mineral. 21, (2009), 467–483. [2] Ph. Freyssinet, C. R. M. Butt, R. C. Morris, P. Piantone, Econ. Geol. 100th Ann. Vol. (2005), 681–722. [3] J. Garnier, C. Quantin, E. Guimaraes, T. Becquer, Miner. Mag. 72(1) (2008), 49–53. [4] A. Wang, K. E. Kuebler, B. L. Jolliff, L. A. Haskin, Am. Miner. 89 (2004), 665–680. [5] E. Ramanaidou, M. A. Wells, D. Belton, Reviews Econ. Geol. 15 (2008), 129–156.

Fig. 1. Reflected optical micrograph (A) of an oxidised spinel-chromite grain. Dark contrast areas are unoxidised; light grey areas are oxidised to hematite. Map of the Cr distribution (B) with high Cr areas (e.g., Site 2) in dark grey and areas of low Cr (e.g., Sites 5 and 7) in black.

Fig. 2. Raman spectra of Sites 2, 5 and 7 as shown in Fig. 1.

ACOVS11/ASC5 Book of Abstracts Session XVI – Forensics

138

SESSION XVI – FORENSICS


139

Evaluation of the Evidentiary Significance of Asphaltene Profiling for Application in Forensic Source Determination of Oil Spills B. J. RILEY1*, V. SPIKMANS1 C. LENNARD1 AND S. FULLER2

1University of Western Sydney, School of Science and Health, Penrith, 2751, NSW, Australia, [email protected] 2Environmental Forensics, Office of Environment and Heritage, Lidcombe, 2141, NSW Australia

Marine oil spills are a constant threat to worldwide coastline environments with approximately 5.74 million tonnes of oil spilt from marine vessels between 1970 and 2013 [1]. Although the quantity of oil spilt in marine environments has decreased drastically in recent decades, incidents falling into the small spill category (<700 tonnes of oil) are still common and collectively attribute to a higher volume of oil spilt annually than the collective volume of large scale incidents (>700 tonnes of oil) [1]. Given the significant impact that an oil spill can have on both marine and coastal environments, marine industries as well as the wellbeing of coastal residents, it is imperative that the responsible party for an oil spill is held accountable for associated financial liabilities. Considerable penalties apply for deliberate and accidental discharge of oil or oil based mixtures into marine waterways, in Australia such offences can warrant penalties up to $10 million with the addition of clean-up costs [2]. It is therefore the responsibility of environmental forensic laboratories to determine the origin or source of the oil spill in order to identify the offender/s [3].

Forensic source determination of marine oil spills is conducted in accordance to various international standards, particularly in accordance to the CEN standard method for the chemical analysis of oils [4]. This method provides a framework for the chemical analysis of oil in which unique chemical profiles are developed for potential source samples. These source sample chemical profiles are compared to the oil spill profile to determine a possible match, in turn identifying the source of the marine oil spill. Oil profiles are attained via Gas Chromatographic (GC) analysis of the volatile fraction, whilst the heaviest oil fraction, the asphaltenes, are discarded due to incompatibility with GC. The volatile fraction is susceptible to weathering when exposed to various environmental factors making interpretation of data potentially difficult when oil samples are weathered [3].

Asphaltenes are large aromatic ring structures (up to 20 rings) [5]. Based on this large structure there is potential that these compounds may be less susceptible to weathering than volatile hydrocarbons and biomarkers. Furthermore, asphaltenes have proven problematic in the fuel industry due to aggregation and precipitation from the bulk oil during oil refining and transportation [6-7]. As a result, asphaltenes have been studied comprehensively with an aim to control these properties. If the assumption is that asphaltenes are likely to resist weathering and with the wealth of literature already available on these compounds, the inclusion of asphaltene profiling in forensic source determination of marine oil spills could effectively complement the existing CEN method.

This research has applied various spectroscopic techniques to the forensic profiling of asphaltenes from various geographically different crude and heavy fuel oil samples. These techniques have proven useful in differentiating these various crude and heavy fuel oil samples based solely on their asphaltene fractions. The evidentiary significance of the data obtained will be determined through the calculation of the discriminating power for each technique. Discriminating power is a forensic measure of the degree of differentiation a technique can achieve. In other words, does the technique have the power to discriminate all samples uniquely or can it simply discriminate samples into groups for the purpose of exclusion? These forensic principles will be discussed in regards to the spectral data obtained in this research. References [1] ITOPF, ITOPF Oil Tanker Spill Statistics (2013). [2] Marine Pollution Act 2012 (NSW) No 5 [3] CEN, Oil spill identification — waterborne petroleum and petroleum products — Part 2: Analytical methodology and interpretation of results based on GC-FID and GC-MS low resolution analyses, (2009), no. CEN/TR15522-2. [4] U. H. Kamalia, Identification of Sources for Illegal Oil Spills by Using GC-MS (Gas Chromatography and Mass Spectrometry) Databases and Multivariate Statisitics, (2011), Norwegian University of Science and Technology. [5] H. Groenzin, O. C. Mullins, Molecular Size and Structure of Asphaltenes from Various Sources, Energy & Fuels, 14 (2000), 677- 684 [6] K. Akbarzadeh, A. Dhillon, W. Y. Svrcek, H. W. Yarranton, Methodology for the Characterization and Modeling of Asphaltene Precipitation from Heavy Oils Diluted with n-Alkanes, Energy & Fuels, 18, 5 (2004), 1434-41. [7] G. González, M. A. Sousa, E. F. Lucas, Asphaltenes Precipitation from Crude Oil and Hydrocarbon Media, Energy & Fuels, 20, 6 (2006), 2544-51.


140

Application of Raman Spectroscopy in the Detection of Cocaine in Food Matrices T. M. BEDWARD1*, L. XIAO1, AND S. FU1

1 Center for Forensic Science, University of Technology Sydney, 15 Broadway, Ultimo, Sydney, 2007, NSW, Australia. E-mail: [email protected]

The abuse, sale, and trafficking of illicit cocaine hydrochloride have been an ever persistence problem in Australia since the drug first became locally established in the late 19th Century [1]. Recently however, the patterns of abuse and smuggling have increased, with recent reports detailing that the illegal transport and the use of cocaine is currently at an all-time high [2]. A large factor in the growing prevalence of cocaine hydrochloride is that the techniques utilised for smuggling cocaine across domestic and international borders have become increasingly complex, allowing a larger amount of the drug to be readily available for sale and distribution. In particular, there has been a greater prominence of cocaine hydrochloride smuggled past customs and border security agencies by concealing the drug within solid food matrices such as baking powder and cake mixes, or dissolved within liquid matrices like Bacardi Superior white rum.

The focus of the experiment was to develop and implement a Raman spectroscopic method that could accurately detect, differentiate, and quantify samples of cocaine hydrochloride hidden within these three main food matrices. The combination of Raman spectroscopy with chemometric processes such as partial least squares regression has been proven effective for many illicit drugs in the past [3], largely due to the ability to provide non-destructive, and unambiguous identification and quantification of molecular compounds with minimal sample preparation required [4].

Initial method development was achieved using samples of atropine, a structure analogue of cocaine, concealed within samples of Anchor brand baking powder, Home Brand butter cake mix, and Bacardi Superior white rum. All spectra were collected using a Renishaw inVia Raman microscope with a Renishaw 785 nm near infrared laser with 1200 l/mm grating. Concentrations of 0%, 10%, 25%, 50%, 75%, and 100% by weight of atropine created as calibration points, with additional samples of 20% and 40% concentrations were also created to act as ‘Unknown’ samples for method validation. To reduce the possible effects of sample inhomogeneity during the collection of spectra, each combined solid sample was ground to a fine powder using an agate mortar and pestle. Furthermore, a series of 25 spectra were collected from independent points within each sample, ensuring a more comprehensive profile of each sample’s unique composition was obtained.

Each of the ‘Unknown’ samples of 20% and 40% concentrations were examined against a digital spectral database which included standard spectra of all compounds used during the project, as well as a multitude of other known pharmaceuticals, illicit substances, and various other samples. Using this database, each unknown spectrum was identified, along with a calculated level of similarity, allowing for comprehensive identifications to me made. This was achieved by using the OMNIC 8.3 Spectra software developed by Thermo Scientific.

Using the Unscrambler X software developed by CAMO, the calibration spectra for each mixed sample underwent three pre-processing techniques; truncation to between 120 cm-1 and 1800 cm-1, normalisation, and baseline offset. Outliers were then removed from each series of spectra based upon comparison of their reference and predicted concentrations, allowing for a more accurate partial least squares regression model to be constructed. The constructed models were primarily validated based upon their Root Mean Standard Error and R2 values, then tested using the ‘Unknown’ samples. Of the atropine mixtures, 80% of the samples hidden with baking powder, and of the samples hidden in the butter cake mix were accurately identified as containing the target drug. Both 40% concentration samples of atropine with cake mix and atropine with baking powder were accurately quantified, with a largest error of ± 4% noted in the predicted concentration.

The developed method was then applied to mixed samples containing cocaine hydrochloride and each of the three noted food matrices. On average, 96% of all cocaine hydrochloride and baking powder samples and 54% of all cocaine hydrochloride and cake mix samples were correctly identified as containing the target drug. No samples of cocaine hydrochloride dissolved in the Bacardi Superior white rim were identified, largely due to the overwhelming Raman spectrum of ethanol. It was found that all the mixed cocaine samples at 40% concentration could be accurately quantified, with a maximum discrepancy between calculated and predicted concentrations of ± 4%. The same accuracy could not be replicated for the 20% samples.

While further optimisation of the method for samples involving a low concentration of cocaine hydrochloride is necessary, the developed method provided strong support for the use of Raman spectroscopy and chemometric processes in the detection, identification, and quantification of cocaine hydrochloride hidden within food matrices. Furthermore, there is strong evidence to support the claim that similar experimental methods would be successful for the analysis of a range of other illicit substances and food matrixes. References [1] W. D. Hall, J. Hando. Patterns of Illicit Psychostimulant Use in Australia. Illicit Psychostimulant Use in Australia (1993) [2] A. Roxburgh, A. Ritter, T. Slade, L. Burns. Trends in Drug Use and Related Harms in Australia, 2001 to 2013. (2013) [2] M. J. West, M. J. Went. “Detection of Drugs of Abuse by Raman Spectroscopy.” Drug Testing and Analysis (2013) 3:9 [2] J. M. Chalmers, H. G. M. Edwards, M. D. Hargreaves. Infrared and Raman Spectroscopy in Forensic Science (2012)


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The Application of Infrared and Raman Spectroscopies to the Characterisation of Automotive Clear Coats for Forensic Purposes W. VAN BRONSWIJK1*, M. MARIC2 AND S. W. LEWIS3

1Department of Chemistry, Curtin University, GPO BOX U1987, Perth, 6076, WA, Australia, [email protected] 2Department of Chemistry, Curtin University, GPO BOX U1987, Perth, 6076, WA, Australia Current address: National Centre of Forensic Science, University of Central Florida, PO Box 162367, Orlando, FL, USA 3Nanochemistry Research Institute and Department of Chemistry, Curtin University, GPO BOX U1987, Perth, 6076, WA, Australia

Over the past few decades, the general public has shown an increased interest in the application of science to crime solving. This can be largely attributed to the proliferation of television shows depicting the use of forensic science in the solving of crimes (e.g. CSI). However, the manner in which forensic science is portrayed in these programmes is highly sensationalised, especially in regards to the forensic analysis and interpretation of trace evidence. The most common misconception is that forensic science is infallible, meaning that the results from the analysis of trace contact evidence cannot be questioned. In reality both USA and UK agencies have highlighted the need to establish impartiality in the analysis and interpretation of forensic evidence. The use of statistical/chemometric techniques enables the development of rigid statistical protocols for obtaining objective conclusions from analytical data. Whilst the work described specifically relates to automotive paint, the statistical methodology developed can be universally applied to other forms of trace evidence.

Automotive paint is a complex multi-layered system most usually consisting of an electrocoat primer, primer surfacer, pigment containing basecoat and a final clear coat. This work has targeted the clear coat as it is almost always encountered as transfer evidence involving motor vehicles. It is also the most easily assessed in-situ (on vehicles) with hand held instrumentation. In this presentation we present the efficacy of ATR-FTIR and FT-Raman spectroscopies for dealing with questioned v. known forensic samples and questioned samples only

From FTIR-ATR spectra of clear coats from vehicles on the road in WA we could clearly distinguish 8 groups, including manufacturers from Australia, Japan, South Korea, Mexico, Thailand, Germany and the USA [1]. That work has been extended and we can now distinguish 17 groups, including different manufacturers within a country (e.g. Mazda, Mitsubishi, Toyota, Subaru, Nissan and Suzuki), models (e.g. Mitsubishi Lancer and Pajero) and years of manufacture (e.g. Holden pre and post 2009) (Figure 1).

Dispersive Raman spectroscopy was unsuccessful due to fluorescence domination of the spectra but FT-Raman spectroscopy generated 19 groups enabling further distinctions to be made (e.g. Mitsubishi Lancer, Pajero, Colt and Holden HSV 2001-2004, 2004-2009, 2009-present) (Figure 2). This highlights the complementary nature of IR and Raman spectroscopies and a combination of the data generated 21 distinct groups.

Whilst the strategy is highly efficacious and objective for assessing automotive clear coat evidence, its limitations will also be presented. References [1] M. Maric, W. van Bronswijk, S.W. Lewis, K. Pitts, (2012) Anal. Methods 4, 2687-2693

Fig. 1. PCA clustering of automotive clear coats based on their FTIR-ATR spectra Fig. 2. PCA clustering of automotive clear coats based on their FT-Raman spectra

ACOVS11/ASC5 Book of Abstracts Session XVII – Chemometrics

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SESSION XVII – CHEMOMETRICS


143

Assumption Free Modeling Approach for the Monitoring and Control of Batch Processes B. SWARBRICK1*, F. WESTAD2, G. R. FLAATEN2 AND L. GIDSKEHAUG2

1Quality by Design Consultancy, 51 Audley Street, Petersham, NSW, Australia, 2049. 2CAMO Software, AS, Nedre Vollgate 8, Oslo, Norway, 0158.

Batch processes are widely studied and used in many research and industrial settings. Typically, starting materials are combined together in a suitable vessel before a chemical, physical or biological transformation takes place, resulting in the end product. In many cases the control of the batch process is recipe driven and not adjusted to accommodate starting material variation or changes in uncontrollable factors to ensure the best possible end product quality and yield. It is well established that real time control of batch processes saves industry money and resources due to less rework and rejects, as well as the opportunity for real time proactive quality assurance.

Some solutions already exist for batch monitoring and control but typically these assume equal lengths of batches, i.e. the batch starts at the same chemical or biological time t0 and has the same number of time points for all batches. This ultimately leads to problems if the batches do not meet these criteria. Alternative approaches to handle uneven batch lengths include replacing time with a maturity index or using dynamic time warping. In both these approaches complications can occur if the first measurement does not coincide with the true t0.

In this paper an improved approach accommodating both uneven batch lengths and unknown true t0 is proposed. The approach is based on projections in the score space so all control options used in MSPC are valid and available. The new approach is demonstrated on data generated by a Near Infrared spectrometer and traditional process data for a biopharmaceutical application.


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Quantitative Raman Spectroscopy of Complex Systems by Hypothetical Addition Multivariate Analysis with Numerical Differentiation M. ANDO1*, S. YABUMOTO2 AND H. HAMAGUCHI1,2

1Research Organization for Nano & Life Innovation, Waseda University, 513 Wasedatsurumaki-cho, Shinjuku, Tokyo, 162-0041 Japan [email protected] 2Institute of Molecular Science and Department of Applied Chemistry, National Chiao Tung University, 1001 Ta Hsuch Road, Hsinchu 300, Taiwan

Accurate determination of concentrations of target molecules in complex mixture systems has long been the central issue of spectrometry. The standard addition method is known to be highly effective for quantitative analysis of mixture systems. However, spectral complexity, band overlapping in particular, often hinders the application of the standard addition method. Instead, many different kinds of multivariate approaches have been developed to overcome this difficulty but so far in vain.

In this study, we propose a new method for quantitative spectrometry, hypothetical addition multivariate analysis with numerical differentiation (HAMAND). It is effective in separating out and quantifying known target spectral components in complex overlapping spectra. A number of hypothetical model spectra are generated numerically by adding to the observed spectrum the known target spectrum multiplied with hypothetical addition coefficients. A set of derivative spectra consisting of the generated hypothetical model spectra and the observed spectrum are subject to a multivariate matrix factorization with L1-norm regularization to yield two spectral components w1 and w2 with intensity profiles h1 and h2. The spectrum w1 is independent of the hypothetical addition coefficient (h1 is constant) and corresponds to the sum of the spectra other than the target. The spectrum w2 is linearly dependent on the hypothetical addition coefficient and corresponds to the target spectrum itself. From the intensity profile h2, we obtain a calibration curve to determine the amount of the target spectrum contained in the observed. This method is an extension of the standard addition method but does not require any tedious procedures for real sample addition. The use of multivariate algorithm enables a full complete utilization of spectral information contained in a spectrum. Multiple target components can also be quantified simultaneously by increasing the rank of matrices. Fig. 1 shows an example separating out and quantifying the contribution of taurine and glucose, as targets, from a commercially available energy drink sample, by using Raman spectroscopy and HAMAND. The taurine spectrum and glucose spectrum are clearly separated out without a priori knowledge of other molecular components in the sample. The intensities of the separated spectra give direct quantitative information on the concentrations of targets.

Fig. 6. Raman spectrum of energy drink (full line), optimized spectrum other than targets (dotted line)

and optimized spectrum of targets: taurine (upper broken line), glucose (lower broken line).


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Synchrotron FTIR microspectroscopy coupled with Principal Component Analysis shows evidence for the cellular bystander effect E. LIPIEC1, K. R. BAMBERY2*, J. LEKKI1, M. J. TOBIN2, C. VOGEL3, D. WHELAN4, B. R. WOOD4 AND W. M. KWIATEK1

1The Henryk Niewodniczanski Institute of Nuclear Physics, PAN, 31-342 Kraków, Poland 2Australian Synchrotron, 800 Blackburn Rd, Clayton, Victoria, Australia [email protected] 3BAM Federal Institute for Materials Research and Testing, Unter den Eichen 87, D-12205 Berlin, Germany 4Centre for Biospectroscopy, School of Chemistry, Monash University, 3800, Victoria, Australia

Synchrotron Radiation - Fourier Transform Infrared (SR-FTIR) microscopy coupled with multivariate data analysis was used to monitor the radiation induced cellular bystander effect. Living prostate cancer PC-3 cells were singly irradiated with various numbers of protons, ranging from 50-2000, with an energy of either 1 or 2 MeV using a proton microprobe. SR-FTIR spectra of cells, fixed after exposure to protons and non-irradiated neighbouring cells (bystander cells) were recorded.

Principal Component Analysis (PCA) was applied to analyse the data set. Spectral differences associated with changes in the nucleic acids and with changes in protein secondary structure were observed in both the directly targeted and the bystander cells. The percentage of affected bystander cells versus the applied number of protons at the two different energies was calculated. It was found that, of all the applied doses, 400 protons at 2 MeV was the most significant in causing macromolecular perturbation in PC-3 bystander cells.

References [1] E. Lipiec, K. R. Bambery, J. Lekki, M. J. Tobin, C. Vogel, D. R. Whelan, B. R. Wood and W. M. Kwiatek, Radiat. Res. 184 (2015), 73-82.

Fig. 1. SR-FTIR spectra of control and irradiated cells, fixed 24 h post irradiation.

ACOVS11/ASC5 Book of Abstracts Session XVIII – Exhibitors

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SESSION XVIII – EXHIBITORS


147

New generation Raman imaging: Confocal 3D Raman imaging meets highest spectral resolution M. KRESS1*, T. DIEING1, S. LEE2, O. HOLLRICHER1, AND U. SCHMIDT1

1WITec GmbH, Lise-Meitner Str. 6, Ulm, 89081, Germany e-mail: [email protected] 2WITec Pte. Ltd., 25 International Business Park #03-59A German Center, Singapore 609916, Singapore

In the past decade confocal Raman imaging has gained in importance for the characterization of heterogeneous materials and is now applied in almost all fields of research. In polymer science phase separation processes, polymorphism, chemical and structural composition can be visualized (1-3). In pharmaceutics the identification and distribution of components in tablets, lotions, powders, and medical devices is a key factor in the development of new products (4-8). In life science, imaging of cells and tissues on a molecular level is possible without specialized labelling or staining, thus allowing the identification of sub-cellular components or follow processes such as drug uptake (9, 10).

Many of the above listed research areas require fast Raman imaging capabilities at the highest possible lateral and spectral resolution. Until recently, the acquisition of high resolution images over large surface areas was limited by computer memory. In addition to this, for high spectral resolution only long focal length spectrographs with comparably low light throughput were available resulting in long integration times and thus impractically long acquisition times for Raman images.

New developments in computer memory management and data acquisition routines facilitate the acquisition of hundreds of thousands Raman spectra in one data file. Fig. 1a shows a 3D Raman image of a carbon-tetrachloride-alkane-water emulsion. This image was acquired from a sample volume of 100x100x10 µm2 by acquiring 200x200x20 = 800000 complete Raman spectra with an integration time of 0.06 s per spectrum. These spectra were acquired with a 600 mm spectrometer equipped with a 300 g/mm grating. Modern Raman data evaluation routines allow a fast identification of the corresponding chemical or molecular species and their distribution in the analyzed sample volume. In this image green color-coding corresponds to the alkane phase, blue to the water phase, and orange to the carbon tetrachloride and oil phase.

The high spectral resolution 2D Raman image (Fig. 1b) was acquired from a sample area of 10x10 µm2 by acquiring 100x100 complete Raman spectra with an integration time of 0.08 s per spectrum. For this high resolution image the same 600 mm spectrometer was used in combination with an 1800 g/mm grating. The short integration time is enabled by the high throughput of the spectroscopic system. In this Raman image the distribution of carbon tetrachloride (yellow colour) was imaged at room temperature. The triplet of Raman bands at 460 rel. 1/cm, characteristic for CCl4, could be clearly resolved (Fig. 1c).

The aim of this contribution is to present the latest achievements in confocal Raman imaging microscopy. As Raman imaging becomes increasingly established as a routine measuring technique for the characterization of heterogeneous materials or devices, the demand for instrumentation with automated measuring routines will grow accordingly. The new generation of confocal 3D Raman imaging microscopes is designed for ease of use without compromising confocality, lateral and spectral resolution, or speed of acquisition of large spectral data sets. Selection of laser wavelength with a mouse click and absolute laser power control with 0.1 mW accuracy are features implemented in an intuitive user interface. The highlights of new generation Raman imaging will be illustrated with examples from various fields of application.

Fig: 1. Confocal Raman imaging study of an emulsion consisting of carbon tetrachloride (orange), alkane (green) and water (blue): 3D Raman image (a), zoom in Raman image with high spectral resolution (b), and high spectral resolution Raman spectrum of carbon tetrachloride acquired at room temperature (c). References [1] J. Zhang et al., Industrial & Engineering Chemistry Research 52, 8616-8621 (2013).


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[2] J. Yang, R. Sekine, H. Aoki, S. Ito, Macromolecules 40, 7573-7580 (2007). [3] U. Schmidt, S. Hild, W. Ibach, O. Hollricher,. Macromolecular Symposia 230, 133-143 (2005). [4] D. Lunter, R. Daniels, Journal of biomedical optics 19, 126015 (2014). [5] B. Kann, B. J. Teubl, E. Roblegg, M. Windbergs, Analyst 139, 5069-5074 (2014). [6] P. D. A. Pudney et al., Applied spectroscopy 67, (2013). [7] B. Mostaghaci, B. Loretz, R. Haberkorn, G. Kickelbick, C.-M. Lehr,. Chemistry of Materials 25, 3667-3674 (2013). [8] C. Matthaus et al., Chemphyschem 14, 155-161 (2013). [9] K. Czamara, J. Natorska, P. Kapusta, M. Baranska, A. Kaczor,. Analyst, (2015). [10] C. Grosse et al., Anal Chem, (2015).


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The reinvention of interleaved time-resolved FT-IR spectroscopy K. TAM1*, A. BALES1, G. ZACHMANN2, M. JÖRGER2 1Bruker Pty Ltd, 7/163-167 McEvoy St, Alexandria, 2015 NSW Australia email: [email protected] 2Bruker Optik GmbH, Rudolf-Plank-Str. 27, 76275 Ettlingen, Germany

Time-resolved FT-IR spectroscopy (TRS) is widely used e.g. to track the kinetics of single shot chemical reactions via Rapid-Scan1-2 or repeatable kinetics via the step-scan3-7 technique. Nevertheless both approaches, Rapid-Scan and Step-Scan, also imply limitations.

Depending on spectral resolution the Rapid-Scan technique is limited to a time resolution in the low millisecond range which is not always sufficient for typical applications of interest. For repetitive kinetics the step-scan technique can overcome these limitations and reach a time resolution down to the low nanosecond range. On the other hand step-scan makes less efficient use of the available measurement time since the necessary mirror repositioning requires interrupting data acquisition and increases the fraction of dead time.

Interleaved time-resolved FT-IR spectroscopy is a technique for a certain class of repetitive kinetics, using the measurement time much more efficiently than step-scan. The interferometer mirror is moving continuously and the zero-crossings of the internal HeNe laser are used to trigger the experiment. Data are not only acquired at the HeNe zero crossings (corresponding to t=0) but also at mirror positions in between, belonging to certain time delays Dt. Hence the system is continuously acquiring data and in principle a full series of time-resolved interferograms can be collected within one single scan.

It is worth mentioning that interleaved should not be confused with so-called stroboscopic FT-IR spectroscopy8 where the interferogram is in general decomposed into several sections, acquired in subsequent scans. Although the interleaved approach is not new9-10 it did so far never establish itself as widely accepted technique. A main reason for this might be the technical limitations of last millennium’s FT-IR spectrometers: in those days electronics such as analog to digital converters as well as the required stability of scanning speed and software interfaces may not have completely met the requirements of high performance interleaved FT-IR spectroscopy.

In our contribution we will introduce the implementation of interleaved FTIR spectroscopy for modern Vertex series FT-IR spectrometers with state of the art electronics and interferometer technology. By means of time resolved emission spectra of an infrared LED (see fig. 1) we will demonstrate the performance and advantages of this “renewed” interleaved technique and compare it to step-scan as well as rapid-scan data.

Nevertheless this new generation of interleaved FT-IR spectroscopy shall not be understood as general replacement for the step-scan technique. Regarding flexibility due to its huge parameter space and its various powerful modifications such as AC coupled differential spectroscopy or modulation techniques, step-scan remains definitely state of the art. However for a certain class of repeatable experiments interleaved FT-IR spectroscopy can be a powerful and easy to use alternative with clear advantages regarding signal to noise ratio and/or measurement duration. References 1 Mantz A.W., (1978), Applied Optics, 17(9), 1347-1351 2 Bengali A.A., Fan W.Y., (2008), Organometallics, 27(21), 5488-5493 3 Palmer R.A., Manning C.J., Rzepiela J.A., Widder J.M., Chou J.L., (1989), Appl. Spectr. 43 4 Uhmann W., Becker A., Taran C., Siebert F., (1991), Appl. Spectr. 45, 390-397 5 Hartland G.V., Xie W., Dai H.L., Simon A., Anderson M.J., (1992), Rev. Sci. Instr. 63, 3261-3267 6 Rammelsberg R., Heßling B., Chorongiewski H., Gerwert K., (1997), Appl. Spectr. 51, 558-562 7 Guttentag, M., Rodenberg, A., Kopelent, R., Probst, B., Buchwalder, C., Brandstätter, M., Hamm, P., Alberto, R., (2012), Eur. J.

Inorg. Chem., 59-64 8 Souvignier G., Gerwert K. (1992), Biophys J., 63(5), 1393-1405 9Weidner H., Peale R.E., (1996), Appl. Opt. 35, 2849–2855 10Cheng J., Lin H., Hu S., He S., Zhu Q., Kachanov A., (2000), Appl. Opt., 39(13), 2221-2229

Fig. 1. Time-resolved emission of an LED with time profile controlled by a function generator, measured via interleaved FT-IR spectroscopy.


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Introduction to HORIBA Scientific R. BENFERHAT

HORIBA INSTRUMENTS (SINGAPORE) PTE LTD, 3 Changi Business Park Vista, #01-01, Singapore [email protected]

The HORIBA Group of worldwide companies provides an extensive array of instrument and system for applications ranging from automotive R&D, process and environmental monitoring, in-vitro medical diagnostics, semiconductor manufacturing and metrology, to a broad range of scientific Research & Development and Quality Control measurements.

HORIBA Scientific products offerings include high-performance spectroscopic instrumentation for Raman, elemental analysis, steady state and lifetime fluorescence, hyperspectral imaging, forensics, optical spectroscopy, OEM spectrometers, TCSPC, GD-OES, ICP, particle characterization, spectral ellipsometry, sulphur-in-oil and X-Ray Fluorescence. By combining the strengths of the research, development, applications, sales, service and support organizations of all, HORIBA Scientific offers researchers the best products and solutions while expanding our superior service and support with a truly global network.

ACOVS11/ASC5 Book of Abstracts Session XIX – Biospectroscopy IV

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SESSION XIX – BIOSPECTROSCOPY IV


152

Spectroscopic identification and analysis of haemoglobin components in bruises J. P. NUNN1*, G. S. WALKER1, K. P. KIRKBRIDE1, N. E. I. LANGLOIS2 AND D. APPADOO3

1School of Chemical and Physical Sciences, Flinders University, Sturt Road, Adelaide, 5042, South Australia, Australia [email protected] 2Department of Pathology, Forensic Science SA, 21 Divett Place, Adelaide, 5000, South Australia, Australia 3THz/Far-IR Beamline, Australian Synchrotron, 800 Blackburn Road, Clayton, 3168, Victoria, Australia

The chemistry that occurs during the formation, maturing and fading of a bruise is complex, as illustrated in Figure 1. Detection and measurement of the components present in a bruise may provide information about the age of the contusion, which can have medico-legal importance. The results of research using spectroscopy, including novel far infra-red (FIR) analysis at the Australian Synchrotron, to distinguish between the compounds present in a bruise in order to predict their proportions over time will be presented.

Visible and near infra-red reflectance spectra were obtained using a Perkin Elmer Lambda 950 UV-Vis.-NIR spectrophotometer with a 150 mm Integrating Sphere accessory. FIR transmission analysis was carried out at the Australian Synchrotron using a Bruker IFS125/HR, extending investigation to the less accessible wavenumber range of 10-1,500 cm-1.

Spectra between 4,000-25,000 cm-1 of individual compounds present in bruises including oxyhaemoglobin, methaemoglobin, ferritin, biliverdin and bilirubin revealed a lack of clear distinction between each other, particularly between biliverdin and bilirubin which are similar in chemical structure (Figure 1). However, FIR transmission spectra of biliverdin and bilirubin exhibited distinctly different features. These differences may be used to predict their proportions in mixtures and in bruises over time.

Further testing in the FIR region will be performed to obtain spectra of other compounds present in bruises to allow their identification and quantification in mixtures.

Acknowledgement Parts of this research were undertaken in the THz/Far-IR beamline at the Australian Synchrotron, Victoria, Australia. Funding is acknowledged from the South Australia Department of Justice Grant, Flinders University. References [1] Nunn, J. P., ‘Spectroscopic Identification and Analysis of Haemoglobin Derivative Coloured Components to Determine Aging of

Bruises’, Honours Thesis, Flinders University, 2012, pp 2. [2] Whitby, F.G., Phillips, J. D., Hill, C. P., McCoubrey, W. & Maines, M. D. 2002, ‘Crystal Structure of a Biliverdin Ixα Reductase

Enzyme-Cofactor Complex’, Journal of Molecular Biology, vol. 319, pp. 1199-1210.

Fig. 1. Interconnectivity of the chemistry associated with bruises [1], including the chemical structures of biliverdin and bilirubin [2].


153

Microstructural Investigation of Biogenic Carbonates in Mollusc Shells with Raman Spectroscopy A. DOWD1*, E. A. CARTER2, M. B. CORTIE1 AND P. A. LAY2

1Institute for Nanoscale Technology, University of Technology Sydney, Broadway, 2007, NSW, Australia [email protected] 2Vibrational Spectroscopy Core Facility, University of Sydney, 2006, NSW, Australia

Complex composite carbonate biomaterials are ubiquitous in Nature but there are still many aspects of their formation and function that are poorly understood. While Raman spectroscopy has been used for some years for the identification of biogenic carbonates [1, 2], advances in Raman microscopy now make high spatial resolution mapping feasible. The specimen preparation is more straightforward than that used for SEM, the usual technique used for biogenic mineral mapping, as the sample needs only to be polished to optical flatness.

We have used Raman microscopy to analyse the shell microstructure of the Australian gastropod Ninella torquata. Two polymorphs of crystalline calcium carbonate, aragonite and calcite, are mapped at high spatial resolution to reveal subtle changes in the mineral gradient in the shell cross-section. No evidence was found for vaterite (Fig. 1 (b)). The ordering of the mineral is also investigated. Within the calcitic outer layer, the calcite at the boundary between calcite and aragonite is more disordered than calcite near the periostracum, possibly because of increased Mg2+ substitution. Crystal orientation can also be investigated by comparing the relative scattering intensities of the lattice modes and we show there is little to no change in aragonite orientation throughout the nacreous material. An organic matrix is deposited alternately with crystalline material during shell growth (Fig. 1 (a)). We map this organic phase which clearly reveals growth layers 5 – 20µm apart and a lamellar mineral structure that extends through most of the thickness of the shell except near the nacreous inner surface. The results can be combined with the output of neutron diffraction studies of the same shell to provide a detailed picture of the microstructure, crystallographic texture and high fracture toughness of these mollusc shells.

References [1] J. Urmos, S. K. Sharma, and F. T. Mackenzie, Am. Mineral. 76 (1991), 641–646. [2] L. Bergamonti, D. Bersani, S. Mantovan and P. P. Lottici, Eur. J. Mineral. 25 (2013) 845-853.

Fig. 1. (a) Map of fluorescence induced by organic molecules showing lamellar structure, (b) map of calcite (red) and aragonite (green) showing clear interface, (c) white light image. Scale bar is 500 µm.


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FTIR Spectroscopic Investigation of Phosphate Polymers for Biomedical Applications S. SUZUKI1*, L. GRØNDAHL2 AND E. WENTRUP-BYRNE3

*1Queensland Eye Institute, 140 Melbourne St., South Brisbane, 4101, QLD, Australia e-mail: [email protected] 2The University of Queensland, Cooper Rd., St Lucia, 4072, QLD, Australia 3Queensland University of Technology, 2 George St., Brisbane, 4001, QLD, Australia

Phosphorous-containing polymers have found many useful applications as coatings, fire-retardants, ion-exchange resins, as well as in biomedical fields. Phosphate functionalities can be achieved either through the phosphorylation of polymers or the polymerization/copolymerization of phosphate-containing monomers [1]. Two suitable commercially available monomers are monoacryloxyethy phosphate (MAEP) and 2-(methacryloyloxy)ethyl phosphate (MOEP) (Fig. 1). In our long term study, we have synthesized graft-copolymers of these monomers onto expanded polytetrafluoroethylene (ePTFE) using the simultaneous γ-irradiation system. Homo- and copolymers were also synthesized using conventional free radical polymerization or Reversible Addition Fragmentation Chain Transfer (RAFT) [2-7]. The resulting polymers were studied for their capability to initiate calcium phosphate (CaP) nucleation and subsequent biomineralization in vitro.

FTIR is a powerful tool for characterizing the molecular structure and composition of synthetic polymers, as well as CaP minerals formed on their surfaces. Using FTIR-ATR in conjunction with other analytical techniques, such as NMR and elemental analysis, we have elucidated a range of possible structures of soluble phosphate polymers formed by the RAFT polymerization process [4]. As a result of this work we serendipitously discovered that the unacknowledged presence of diene impurities in these monomers; these were subsequently incorporated into the polymer structures [5]. In addition, the cleavage of the phosphate esters as a result of acid-catalysed hydrolysis for the methacrylate polymer (PMOEP) was revealed. In the case of the acrylate polymer, PMAEP, IR data also showed that cleavage of the side chains at the C-O-C ester linkages during polymerization. The degree of crosslinking in the gel samples was reflected in the IR spectral data as a consequence of the phosphate group’s ability to participate in strong hydrogen bonding. In addition, FTIR spectroscopic imaging proved very useful in mapping the uneven grafting of the phosphate polymers onto the ePTFE membranes (Fig. 2) [7]. CaP minerals have been extensively studied using FTIR for many years and in conjunction with SEM-EDX it helped to identify the CaP species formed on our phosphate polymers after soaking in simulated body fluid. We successfully demonstrated that the amount of phosphate groups, surface wettability, and the degree of crosslinking, as well as the accessibility of the phosphate groups themselves all play an important role in both the amount and type of mineral formed. This study highlights the usefulness of FTIR in the full characterization of synthetic phosphate polymers for biomedical applications.

References [1] E. Wentrup-Byrne, S. Suzuki, L. Grondahl, In Phosphorus-based polymers from Synthesis to Applications; S. Monge, G. David (Eds.), RSC Polymer Chemistry Series RSC: Cambridge, UK (2014), 167-209 [2] A. F. Chandler-Temple, E. Wentrup-Byrne, H. J. Griesser, M. Jasieniak, A. K. Whittaker, L. Grøndahl, Langmuir, 26 (2010), 15409-15417 [3] A. Chandler-Temple, P. Kingshott, E. Wentrup-Byrne, A. I. Cassady, L. Grøndahl, J. Biomed. Mater. Res. 101A (2013), 1047-1058 [4] S. Suzuki, M. R. Whittaker, L. Grøndahl, M. J. Monteiro, E. Wentrup-Byrne, Biomacromol. 7 (2006), 3178-3187. [5] L. Grøndahl, S. Suzuki, E. Wentrup-Byrne, Chem. Commun. (2008), 3314-3316 [6] E. Wentrup-Byrne, S. Suzuki, J. J. Suwanasilp, L. Grøndahl, Biomed. Mater. 5 (2010), 045010 [7] S. Suzuki, E. Wentrup-Byrne, A. Chandler-Temple, N. Shah, L. Grøndahl, J. Appl. Polym. Sci. (2015) Accepted.

Fig. 2. Micro-ATR/FTIR maps of MAEP grafted ePTFE showing the ratio of the C=O to C-F vibrational modes displayed in (A) 2D and (B) 3D views

Fig. 1. Chemical structure of the monomer


155

Adipocytes: A Key to Unlocking the Secrets of Glucose Metabolism E. A. CARTER1,2*, A. LEVINA, A. I. MCLEOD, A. SAFITRI2, S. TARR2, S. GASPARINI2, J. LEONG2, M. WOOD2 AND P. A. LAY1,2

1Vibrational Spectroscopy Core Facility, Madsen Building F09, The University of Sydney, Camperdown, 2006, NSW, Australia [email protected] 2School of Chemistry F11, The University of Sydney, Camperdown, 2006, NSW, Australia

Diabetes mellitus is a chronic metabolic disease, in which blood glucose levels become too high, due to the inability of the body respond to, or produce the hormone insulin. Insulin regulates the metabolism of carbohydrates and fats and transports the glucose from blood cells into the muscle and fat (adipocyte) cells where it can store the fat in addition to using it for energy.

There are three major types of diabetes: Type 1, Type 2 and gestational diabetes. In 2014 it was estimated that there were 387 million people in the world who were living with diabetes, which is 8.3% of the adult population [1]. Type 2 diabetes accounts for at least 90% of all cases of diabetes, and is characterised by insulin resistance.

Adipocytes (fat cells) are one of the two main glucose metabolising cells in the body and in diabetes these cells have an altered glucose metabolism. Glucose uptake into adipocytes is instigated via insulin binding to receptors on the surface of the cell. Investigation of glucose metabolism in adipocyte cell lines, such as murine 3T3-L1, is important to develop an understanding of diabetes and the potential effects of drug treatments.

Methods of monitoring the uptake and metabolism of glucose are important in developing our understanding of diabetes and developing drug targets and testing the efficiency of drugs. Therefore, methods of tracking the metabolism of glucose in a simple and cost effect way are required. This is an area of research that the group has been involved in for some years and we have developed a sampling protocol that includes culture, differentiation and fixing of cells in their preferred morphology on the one sample substrate (Si3N4) to enable subsequent diverse modern microspectroscopic analyses to characterise the adipocyte intracellular biochemistry [2].

Recent technological developments in the area of Raman spectroscopy now allow for samples to be investigated using 3D volume mapping (tomography). Our latest research uses a combination of FTIR imaging and Raman 3D tomography to investigate the microstructure of adipocytes and to further our knowledge of metabolic processes in response to different sugars or other substrates and the efficacy of anti-diabetic drugs and trace metals in improving cell signaling and biological functions. Acknowledgement This research has been supported by ARC Discovery grants to PAL, and ARC LIEF, NHMRC and University of Sydney Equipment grants to PAL and EAC. We are also grateful for support from the Australian Synchrotron Research Program, the Australian Synchrotron, and the National Synchrotron Radiation Research Center (Taiwan). References [1] https://www.idf.org/worlddiabetesday/toolkit/gp/facts-figures [2] E. A. Carter, B. S. Rayner, A. I. McLeod, L. E. Wu, C. P. Marshall, A. Levina, J. B. Aitken, P. K. Witting, B. Lai, Z. Cai, S. Voght, Y-.C. Lee, C.-I. Chen, M. J. Tobin, H. H. Harris, P. A. Lay, Mol. BioSyst., (2010), 6, 1316-1322, DOI: 10.1039/c001499k

ACOVS11/ASC5 Book of Abstracts Session XX – Environmental

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SESSION XX – ENVIRONMENTAL


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Reactivity and Spectroscopy of Simple Criegee Intermediates and Implications in Atmospheric Chemistry J. J. LIN1,2

1Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan. [email protected] 2Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan

Ozonolysis of unsaturated hydrocarbons produces highly reactive Criegee intermediates, which are thought to play an important role in atmospheric chemistry, in particular, the oxidation of SO2. The SO3 product in the SO2 oxidation would form H2SO4 subsequently through reaction with water; H2SO4 is an important constituent of aerosols and acid rain. However, the impact of such oxidation reactions would be affected by the reactions of Criegee intermediates with water vapour, because of high abundance of water vapour in the troposphere.

We have measured the UV absorption spectra of a few simple Criegee intermediates, including CH2OO, syn-/anti-CH3CHOO, and (CH3)2COO. The reaction kinetics of these simple Criegee intermediates with water, water dimer, and SO2 have been investigated through monitoring a given Criegee intermediate with its UV absorption.

While (H2O)2 efficiently scavenges CH2OO under typical atmospheric conditions, we will show that the reactivity of a Criegee intermediate towards water and water dimer depends strongly on its structure. A simple methyl substitution may alter the rate coefficient by orders of magnitude, such that some Criegee intermediates would not be consumed by reaction with water. These Criegee intermediates may be potential candidates for efficient oxidants in the atmospheric SO2 oxidation.

Reference [1] W. Chao, J-T Hsieh, C-H Chang, J. J. Lin, Direct kinetic measurement of the reaction of the simplest Criegee intermediate with water vapor. Science 347(2015), 751-754.


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Infrared Spectroscopy of Criegee Intermediates (CH2OO, CH3CHOO, and (CH3)2COO) and Iodoalkylperoxyl Radicals (ICH2OO) Y.-P. LEE1,2*, Y.-H. HUNAG1, L.-W. CHEN1, AND Y.-I. WANG1

1Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001, University Road, Hsinchu 30010, Taiwan [email protected] 2Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan

The Criegee intermediates (CI), carbonyl oxides proposed by Criegee in 1949 as key intermediates in the ozonolysis of alkenes, play important roles in many aspects of atmospheric chemistry. Because direct detection of these gaseous intermediates was unavailable until recently, previous understanding of their reactions, derived from indirect experimental evidence, had great uncertainties. Recent laboratory detection of the simplest Criegee intermediate CH2OO and some larger members, produced from ultraviolet irradiation of corresponding α-diiodoalkanes in O2, with various methods such as photoionization, ultraviolet absorption, infrared absorption, and microwave spectroscopy opens a new door to improved understanding of the roles of these Criegee intermediates. Their structures and spectral parameters have been characterized; their significant zwitterionic nature is hence confirmed. CH2OO, along with other products, has also been detected directly with microwave spectroscopy in gaseous ozonolysis reactions of ethene. (A) Spectrum of CH2OO at 0.25 cm−

1 resolution Using the same production scheme of CH2I + O2, Su et al. produced CH2OO in a multipath White cell and recorded

its transient IR absorption spectrum with a step-scan Fourier-transform infrared (FTIR) spectrometer.1 The vibrational wavenumbers and rotational contours of five observed bands provide identification of this intermediate on comparison with theoretical predictions. The observed wavenumber of the O−O stretching mode of CH2OO near 908 cm−

1 is smaller than that of the corresponding modes of CH3OO at 1117 cm−

1, CH3C(O)OO at 1102 cm−1, and C6H5C(O)OO at 1108

cm−1 determined with a similar technique, indicating a weak O‒O bond. In contrast, the observed wavenumber of the

C−O stretching mode near 1286 cm−1 is much greater than that of the corresponding mode of CH3OO at 902 cm−

1 observed in a matrix, indicating significant double bond character. A strengthened C−O bond and a weakened O−O bond imply that CH2OO has a significant zwitterionic character.

With an improved detection technique Huang et al. recorded an infrared spectrum of CH2OO at resolution 0.25 cm−1

with rotational lines partially resolved.2 In addition to the derivation of more accurate vibrational wavenumbers and some critical spectral parameters to confirm the preceding assignments, the rotational structures of bands in that spectrum led to correct assignments for modes 2ν9 and ν5. With improved resolution, the ν5 band previously reported near 1241 cm−

1 appears as part of the R-branch of the 2ν9 band at 1233.5 cm−1. The weak ν5 band at 1213.0 cm−

1 is now clearly identified. Observed vibrational wavenumbers, relative intensities, and rotational structures show significantly improved agreements with those predicted by high-level MULTIMODE calculations.

(B) Spectrum of ICH2OO and the pressure dependence of the yield of CH2OO

It is generally accepted that the source reaction proceeds via two major channels: CH2I + O2 → CH2OO + I, (1) CH2I + O2 + M → ICH2OO + M, (2)

in which the rate coefficients k1 and k2 are pressure dependent because the stabilization of the adduct ICH2OO, iodomethyl peroxy radical, depends on removal of its excess energy via collision. The pressure dependence of these rate coefficients have been characterized by probing simultaneously ultraviolet absorption of CH2I2, CH2OO, CH2I, and IO upon photolysis at 248 nm of a flowing mixture of CH2I2, O2, and N2 in the pressure range 7.6−779 Torr.3, 4 At pressure below 60 Torr, an additional decomposition channel of CH2I + O2 to form products other than CH2OO or ICH2OO becomes important. Despite the importance of ICH2OO in atmospheric chemistry, its spectral signature is little known. A UV spectrum of ICH2OO with a broad and structureless feature in the range 250‒450 nm has been reported. However, according to theoretical calculations, ICH2OO might not be the principal carrier of this observed spectrum; the UV absorption of CH2OO, ranged 260‒460 nm with a maximal cross section of 1.2×10‒17 cm2 molecule−

1 at 340 nm, might contribute significantly to this feature. The only definitive spectral characterization of ICH2OO is its IR spectrum in matrix isolation.5 This spectrum of syn-ICH2OO was recorded upon irradiation of a p-H2 matrix containing CH2I2 and O2 at 3.2 K with light at 280 ± 20 nm, followed by annealing of the matrix at 4.0 K. Nine vibrational features of syn-ICH2OO at 2982.4, 1408.9, 1231.8, 1226.5/1225.6, 1085.6, 917.7, 841.6/841.1, 550.5, and 490.2 cm−

1 were characterized, indicating that ICH2OO is the major product from CH2I + O2 in an environment in which energy is rapidly quenched.

Fig. 1. Spectrum of CH2OO recorded at resolution 0.25 cm−1. The vibrational mode assignments are indicated.

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We recently recorded the infrared spectrum of ICH2OO using the same reaction at pressure greater than 100 Torr using a step-scan FTIR spectrometer. Observed four bands, near 1233.8, 1221, 1087, and 923 cm−

1, of gaseous ICH2OO in the CH2I + O2 system, agrees with that simulated according to theoretical predictions. For the first time, both products CH2OO and ICH2OO were observed simultaneously with the same technique. With direct detection of both CH2OO and ICH2OO, we determined the pressure dependence of the yield of CH2OO. The yield of CH2OO near one atmosphere is greater than previous reports; it might have significant consequence in atmospheric chemistry.

(C) Spectrum of syn-CH3CHOO and syn-CH3CHOO and their distinct reactivities

Methyl substitution of CH2OO that induces two conformers of CH3CHOO complicates the IR spectrum. We recorded the transient IR spectrum of both syn- and anti-CH3CHOO, produced from UV photolysis of a mixture of CH3CHI2 and O2 in a flow reactor.6 Guided and supported by high-level full-dimensional quantum-chemical calculations, we simulated rotational contours of the four observed bands that provide definitive identification of both conformers. This simulation implies that (1) the hot bands are all blue-shifted from the fundamental; the unusual but necessary blue shifts of about 2 and 10 cm−

1 for the hot bands involving ν18 and ν12 of syn-CH3CHOO, respectively, agree qualitatively with the theoretical predictions. The calculations also indicate that torsional splitting is small for all vibrational modes so that it affects little our spectral simulation. (2) At 328 K, assuming a Boltzmann distribution and that the IR intensities of hot bands are the same as that of the fundamental band (in qualitative accord with calculations), observed relative intensities of these hot bands imply energies of the first excited states of ν18 and ν12 modes of syn-CH3CHOO and those of ν18 and ν17 of anti-CH3CHOO to be ~193, 282, 149, and 239 cm−

1, respectively, which is consistent with theoretical predictions, and (3) the population fraction of anti-CH3CHOO is 0.30 and 0.38 at 328 K, respectively, if IR intensities predicted with the B3LYP and MULTIMODE methods are used. This fraction is consistent with a value of ~0.30 derived from UV experiments, but greater than values ~0.20 from microwave experiments and ~0.10 from photoionization experiments.

The characteristic OO-stretching modes of syn- and anti-CH3CHOO are identified at 871.2 and 883.7 cm−

1, respectively, slightly less than that (909.2 cm−

1) of CH2OO. Although nearly all observed bands of anti-CH3CHOO overlaps with syn-CH3CHOO, the Q-branch of ν8 near 1090.6 cm−

1 is contributed solely by syn-CH3CHOO, and that of ν7 near 1280.8 cm−

1 is also dominated by syn-CH3CHOO. Furthermore, anti-CH3CHOO is more reactive than syn-CH3CHOO toward NO or NO2; the spectrum recorded at a later stage can consequently be simulated with only syn-CH3CHOO. Even without NO or NO2, anti-CH3CHOO also decayed much more rapidly than syn-CH3CHOO.

If time permits, IR spectrum of (CH3)2COO and its iodoalkyl peroxy radical (CH3)2CIOO will also be discussed. Acknowledgement Ministry of Science and Technology of Taiwan (Grant No. MOST103-2745-M009-001-ASP) and Ministry of Education, Taiwan ("Aim for the Top University Plan" of National Chiao Tung University) supported this work. National Center for High-performance Computing provided computer time. References [1] Y.-T. Su, Y.-H. Huang, H. A. Witek, Y.-P. Lee, Science, 340 (2013) 174‒176. [2] Y.-H. Huang, J. Li, H. Guo, Y.-P. Lee, J. Chem. Phys. 142 (2015) 214301. [3] Y.-T. Su, H.-Y. Lin, R. Putikam, H. Matsui, M. C. Lin, and Y.-P. Lee, Nat. Chem. 6 (2014) 477‒483. [4] W.-L. Ting, C.-H. Chang, Y.-F. Lee, H. Matsui, Y.-P. Lee, Jim J.-M. Lin, J. Chem. Phys. 141 (2014) 104308. [5] Y.-F. Lee and Y.-P. Lee, Mol. Phys. DOI: 10.1080/00268976.2015.1012129. [6] H.-Y. Lin, Y.-H. Huang, X. Wang, J. M. Bowman, Y. Nishimura, H. A. Witek, Y.-P. Lee, Nat. Comm. 6 (2015) 7012.

Fig. 2. Comparison of observed spectra with predicted spectra of ICH2OO. Spectrum recorded 0.6‒7.0 µs upon UV irradiation (A and B). (C) Spectrum in (B) with CH2OO and CH2I2 stripped. New features are labeled as A1‒A3. Possible ranges of anharmonic vibrational wavenumbers and IR intensities of (D) syn-ICH2OO and (E) anti-ICH2OO predicted with various methods are shown as filled rectangles.

Fig. 3. Comparison of observed spectra with predicted spectra of ICH2OO. Spectrum recorded 0.6‒7.0 µs upon UV irradiation (A and B). (C) Spectrum in (B) with CH2OO and CH2I2 stripped. New features are labeled as A1‒A3. Possible ranges of anharmonic vibrational wavenumbers and IR intensities of (D) syn-ICH2OO and (E) anti-ICH2OO predicted with various methods are shown as filled rectangles.

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Measurement of absorption spectrum of the propionyl radical (CH3CH2CO) radical using Cavity Ring Down Spectroscopy (CRDS) G. SRINIVASULU1, B. RAJAKUMAR1* 1Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.

The propionyl radical, CH3CH2CO, is of importance in both atmospheric and combustion chemistry.1,2 The CH3CH2CO, radical is formed in the Earth's atmosphere in several ways including the reactions of OH radicals with CH3CH2C(O)H and as a primary product in the UV photolysis of carbonyl compounds such as methyl ethyl ketone (CH3C(O)CH2CH3,MEK), diethyl ketone (CH3CH2C(O)CH2CH3 DEK) and acetyl halides like propionyl chloride (CH3CH2COCl). In the atmosphere, CH3CH2CO radical is rapidly converted to propionylperoxy radical via its reaction with O2.3

Propionylperoxy radical, in turn leads to the formation of peroxypropionylnitrate4 (PPN, CH3CH2C(O)O2NO2) in the

nitrogen rich environment. PPN is an atmospheric reservoir for NOX (NO+NO2). PPN concentrations of up to 4 ppb have been measured and reported in urban areas5.

The visible absorption spectrum of the acetyl radical, CH3CH2CO was measured between 555 and 595 nm at 298 K

using cross photolysis cavity ring-down spectroscopy, and is shwon in the below given figure. The radicals were produced using OH +CH3CH2CHO → CH3CH2CO +H2O reaction with pulsed laser photolysis source of OH radicals. The details of the experimentation and the interpretation of the spectrum will be presented in the talk. References: [1] E. W. Kaiser, C. K. Westbrook, and W. J. Pitz, Int. J. Chem. Kinet. 1986, 18, 655. [2] B.Rajakumar, Jonathan E. Flad,Tomasz Gierczak, A. R. Ravishankara,James B. Burkholder, J. Phys. Chem. A 2007, 111, 8950. [3] H. Hou, B. Wang, J.Chem.Phys 2007, 127, 054306. [4] J. A. Kerr and D. W. Stocker, J. Photochem. 1985, 28, 475 [5] Grosjean, D., E. L. Williams, E. Grosjean, J. M. Andino, and J. H. Seinfeld, Environ. Sci. Technol., 1993. 27(13), 2754.


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Measuring from a Distance - Remote Sensing By FTIR Technology A. BALES1*, P. MAAS2, A. GEMBUS2 1Bruker Pty Ltd, 7/163-167 McEvoy St, Alexandria, 2015 NSW Australia email: [email protected] 2Bruker Optik GmbH, Rudolf-Plank-Str. 27, 76275 Ettlingen, Germany

Remote sensing by infrared spectrometry is a well-established method for detection of gases in the atmosphere. Using this method it is possible to detect gases from long distances, up to several kilometers. Spectral analysis algorithms enable the identification and quantification of target gases without a prior knowledge of the background signature1. Also solids and liquids can be analyzed from a distance by the use of FTIR hyperspectral sensors. There are different methods with distinct characteristics which are used in a variety of different applications. From security and defense to atmospheric sciences and environmental research this the remote sensing technology has also arrived in industrial applications. Imaging FTIR systems allow for automatic identification but also a simple interpretation of the result, the image of the cloud2.

Different needs require different technical approaches. In passive remote sensing the principle corresponds to the human eye. Ambient infrared radiation is captured by a spectrometer and analyzed for spectroscopic signatures of target gases without the need for external sources. Since thermal radiation is used no sun light is needed for the passive method which allows for day and night measurements.

One of many important applications is the use by security and hazard control forces. Whereas conventional measurement techniques require the collection of a sample, which may be dangerous, time-consuming and difficult for example in the case of a terrorist attack in a stadium or a crowded public place. In contrast, remote sensing by infrared spectrometry allows instant identification of hazardous clouds from a distance.3 Imaging FTIR spectrometers are especially well suited to protect high profile events from threats of hazardous gas clouds, be it a terrorist attack, accidents or natural events. Also highly toxic chemical warfare agents can be identified from large distances2, which is a huge advantage compared to conventional measurement technology. Besides the scanning infrared gas imaging system (SIGIS 2) the imaging FTIR spectrometer HI90, a high performance hyperspectral sensor is available for these applications.

After several years of practical use by fire fighters in several different countries, the infrared remote sensing technique has also been adapted to industry for the surveillance of production and storage facilities. The systems can be employed in 24 h/day 7 days/week surveillance applications, to scan large industrial areas to detect leakages and to prevent larger accidents caused by hazardous compounds. In case a target gas is identified an alarm is automatically generated. The combination of several passive imaging systems moreover allows the tomographic reconstruction of gas clouds and the generation of measured 3D cloud models that can be loaded in a Geographical Information Software (GIS)4.

The FTIR technology is also especially well known among atmospheric and environmental scientists. The systems are used to study the composition of the atmosphere by analyzing the radiation of the sun that passes through the atmosphere, as well as for ground-based comparisons of satellite measurements. Within the last several years, it has been recognised that a precise knowledge of the global abundances of greenhouse gases such as CO2, N2O and CH4 is required for understanding the mechanisms of the global carbon cycle and to determine its sources and sinks. A new analyzer, the EM27/SUN, is a small, lightweight and a mobile sun spectrometer offering outstanding precision. During comparison measurements with high resolution FTIR spectrometers of the Total Carbon Column Observing Network (TCCON) FTIR agreement results of (0.12 ± 0.08) % are achieved. This makes the spectrometer a promising candidate for a low-cost addition to the TCCON core FTIR sites, especially suitable for locations with limited infrastructure. Impressive mechanical and thermal stability is proved, enabling the spectrometer to be used in field campaigns and for the monitoring of local sources5. Other important areas of research for the EM27/SUN in conjunction with the standard EM27 are volcanology and study of the impact of anthropogenic emissions, as well as industrial flare measurements.

The use of active open path spectrometers (OPS) allows simultaneous high precision measurements of several hundred compounds, covering large distances on the ground. Modulated radiation is sent out through a telescope towards a retro reflector array over distances of up to around 600 m, thus active optical measurement paths of up to 1.2 km can be achieved providing low detection limits of atmospheric trace gases at highest precision for surveillance of large industrial areas in a fence line monitoring application. Leaked gases can be identified in very small concentrations in the ppb or even sub-ppb range, depending on the compound. This allows for hazard control as well as the determination of odors and environmental poisons.

The newest generation of imaging FTIR spectrometers employ a focal plane array detector to measure many thousands of complete infrared spectra in a single scan of the interferometer. The high performance is achieved with the Bruker HI90 which uses an actively aligned plane mirror interferometer together with state of the art cryogenic IR detectors. With its high sensitivity, its high spatial and temporal resolution it is the most flexible instrument in the portfolio. The retrieved spectral information can be used to establish chemical images and analyze solids, liquids and gases in milliseconds. Plumes as far as 25 km have been detected. Spectral analysis algorithms can be combined with image processing algorithms to allow for many different applications.

Recently the HI90 Spectral Imaging system has been used in Australia to detect uncontrolled methane spills from anthropogenic sources in connection with the unconventional options of producing fossil fuels. The sheer size of the


162

surveillance area, 100,000 square kilometres, makes the use of passive imaging FTIR instruments a suitable choice during the search for uncontrolled events and the study of the anthropogenic impact into the emission of greenhouse gases. References [1] S. Sabbah, R. H.-H. (2012, November). Remote sensing of gases by hyperspectral imaging: system performance and measurements. Optical Engineering. [2] R. Harig, P. R. (2005). Remote Measurement of Highly Toxic Vapours by Scanning Imaging Fourier-Transform Spectrometry. Chemical and Biological Standoff Detection III, Proceedings of SPIE Vol. 5995. [3] R. Harig, G. M.-H.-H. (2007, May). Infrared remote sensing of hazardous vapours: surveillance of public areas during the FIFA Football World Cup 2006. Proc. SPIE 6538. [4] P. Rusch, R. H. (2010, March). 3-D Reconstruction of Gas Clouds by Scanning Imaging IR Spectroscopy and Tomography. IEEE Sensors Journal. [5] M. Gisi, F. H. (2012, November). XCO2-measurements with a tabletop FTS using solar absorption spectroscopy. Atmospheric Measurement Techniques.

ACOVS11/ASC5 Book of Abstracts Poster Session II

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POSTER SESSION II


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Spectroscopy of solid-state microbial fermentation: fingerprinting for button mushroom production K. M. SAFIANOWICZ1*, T. BELL1 AND M. KERTESZ1

1Faculty of Agriculture and Environment, University of Sydney, 1 Central Ave, Eveleigh, 2015, NSW, Australia; [email protected]

Button mushroom (Agaricus bisporus (Lange) Sing.) is the most popular mushroom crop in Western countries and comprises 98% of total Australian mushroom production. Button mushrooms are cultivated on a straw-based compost that results from a complex, 6-week long solid-state microbial fermentation process. Current knowledge of compost quality biomarkers is still insufficient for development of measures and practices that ensure consistently high quality of the final product. At the same time, building basic knowledge of the microbial "active ingredients" in compost is hampered by substantial spatial variability in large-scale commercial composting operations, and by the complexity and fragility of sampled material, which changes dramatically with storage. Diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) allows for rapid analysis of a large number of samples with minimal pre-processing, and has been used with some success to predict chemical properties of the compost and mushroom yields from compost spectral fingerprints. As a proof-of-concept, we followed an experimental batch of compost throughout the composting process and mushroom production stages, collecting bacterial DNA and DRIFTS fingerprints. Changes in spectral characteristics of the compost paralleled changes in diversity of bacterial communities, and clearly differed between various stages of the process, at several time points. These results indicated that DRIFTS can be used for investigating and monitoring microbially-driven changes that occur during preparation of button mushroom compost, and suggest several potential avenues for further research


165

FTIR and Raman analysis of Colonial medicine chest bottles held in the collection of the National Museum of Australia A. TREASURE1*, V. OTIENO-ALEGO2 AND N. SMITH3

1University of Canberra, University Dr, Bruce, ACT, 2617, Australia [email protected] 2Australian Federal Police, Cnr Unwin Place & Streeton Dr, Weston, ACT, 2611, Australia 3National Museum of Australia, Lawson Crescent, Acton Peninsula, Canberra, ACT, 2601, Australia

A collection of Colonial period medicine bottles and remains of a medicine chest were donated to the National Museum of Australia in 2006 by the great grandson of John Spear (Speer), a 19th century convict assigned to work with Dr Patrick Hill. Dr Hill owned property near Goulburn, NSW and was a Medical Officer at Parramatta and Liverpool in the 1840s. He gave the medical supplies to John Speer, who himself became a free man and obtained his own land. Generations of the Speer family subsequently used the medicines for cuts or ailments within the family and also for shearers and station hands.

In the days when doctors were some distance away and usually only called for emergencies or grave illnesses, property owners would often keep a stocked medicine chest for 'everyday' health issues, and this is one such historically significant chest. Most of the medicines contained have been superseded by modern drugs and are no longer in use. Some are now known to be harmful.

With incomplete or no labelling, many of the bottles also broken, identification of the contents of the chest was sought. Approximately forty samples, both liquid and solid, have been analysed using FTIR and Raman spectroscopy. Waxes, organic plant based products, acids and ethanol based solutions have been included in the findings. Complimentary analysis, SEM-EDS and GCMS, has been employed for samples as required, in particular those that are mixtures. Identification of resultant spectra continues.


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Characterisation of Microscopic Organic Residues Preserved on Ancient Stone Tools using SR-FTIR Spectroscopy E. A. CARTER1*, M. WOOD1, S. J. KELLOWAY2, N. KONONENKO3 AND R. TORRENCE3

1Vibrational Spectroscopy Core Facility, Madsen Building F09, The University of Sydney, Camperdown, 2006, NSW, Australia [email protected] 2Solid State & Elemental Analysis Unit, Mark Wainwright Analytical Centre, University of NSW, Kensington, 2052, NSW, Australia 3Australian Museum, 6 College St., Sydney, 2010, NSW, Australia

Microscopic deposits of materials embedded within irregularities on the edges of stone tools can help identify which artefacts were used in the past and in which kinds of activities (e.g., hunting, butchery, processing plant foods, carving wood). In some cases it is possible to identify the particular animal or plant species exploited. Recent studies have identified early examples of tattooing tools in the Pacific region [1-3] and early stone points in Australia have been shown to have had multiple functions rather than only being used as specialized hunting equipment [4]. Studies in China and the Near East have detected early examples of seed processing that were important forerunners of agricultural practices [5-6].

The types of techniques available for studying residues are restricted because the size and quantity of material preserved is very small. With rare exceptions, residues on stone tools are only detectable through high power microscopy or in some cases with destructive chemical tests. A non-destructive analytical technique for characterization and identification of these ancient traces is essential as they are quite rare and not replaceable.

A range of vibrational spectroscopic experiments have been undertaken at the Vibrational Spectroscopy Core Facility, at the University of Sydney [7-8]. Using standard laboratory instruments it was possible to discriminate between modern reference samples of various animal proteins and plant materials mounted on metal slides using both Raman (1064 nm, 514 nm) and FTIR spectroscopy (reflection mode) [9]. However, we had limited success detecting residues on modern, experimental and ancient obsidian tools. Experiments at the Australian Synchrotron were undertaken to investigate the potential of SR-FTIR spectroscopy for the detection and analysis of microscopic residues on stone tools. This presentation will discuss the findings of these SR-FTIR spectroscopic experiments whereby spectra were obtained from blood and plant residues on modern experimental obsidian tools as well as from a blood residue on an artefact c. 3000 years old and from starchy material on several artefacts older than 3000 years.

Acknowledgement This research was supported by the Australian Research Council (ARC Discovery and ARC LIEF grants) and the Australian Museum. References [1] N. A. Kononenko, 2011. Experimental and Archaeological Studies of Use-Wear and Residues on Obsidian Artefacts from Papua

New Guinea. Technical Reports of the Australian Museum, Online 21:1-244 http://dx.doi.org/10.3853/j.1835-4211.21.2011.1559 [2] N. A. Kononenko, Archaeology in Oceania 47 (2011) 14-28. [3] N. A. Kononenko, R. Torrence, Antiquity, 83(2009) 320, http://antiquity.ac.uk/projgall/kononenko/ [4] V. Attebrow, G. Robertson, P. Hiscock, J. Archeol. Sci., 36 (2009) 2765-2770. [5] D. Piperno, E. Weiss, I. Hoslt, D. Nadel, Nature 430 (2004), 670-673. [6] L. Liu, W. Ge, S. Bestel, D. Jones, J. Shu, Y. Song, X. Chen, J. Archeol. Sci., 38 (2011) 3524-3532. [7] E. A. Carter, M. D. Hargreaves, N. A. Kononenko, I. Graham, H. G. M. Edwards, B. Swarbrick, R. Torrence, Vib. Spectrosc., 50

(2008) 116-124. [8] S. J. Kelloway, N. A. Kononenko, R. Torrence, E. A. Carter, Vib. Spectrosc., 53 (2010), 88-96. [9] E. A. Carter, S. J. Kelloway, N. A. Kononenko, R. Torrence, R., In Analytical Archaeometry, Eds. H. G. M. Edwards, P.

Vandenabeele, Royal Society of Chemistry. (2012) 323-349.


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Vibrationally Elastic Cross-sections for Electron Interactions with Environmentally Related Methane Molecules M. KAUR1,2*, A. K. JAIN1, H. MOHAN1, P. S. SINGH2 AND S. SHARMA3

1Department of Physics, M.L.N. College, Yamuna Nagar, 135 001, Haryana, India [email protected] 2Department of Physics, Punjabi University, Patiala, 147 002, Punjab, India 3Department of Chemistry, M.L.N. College, Yamuna Nagar, 135 001, Haryana, India

Methane (CH4) is one of the preferred targets in the electron-molecule spectroscopic studies due to its simple structure (i.e. nearly spherical). Knowledge of electron impact vibrational excitations of methane molecule is essential in a number of industrial and atmospheric applications. In case of applications in industries, interaction of electrons plays a significant role which includes chemical vapour deposition for the production of the artificial diamond and the development of nanocrystalline diamond films and carbon nanotubes. Apart from this, there are several other applications in the field of radiation detector, gaseous laser media, gaseous discharge and in electron impact induced chemical reactions on surfaces. As far as atmospheric applications are concerned, molecules of methane play an important role in establishing network of greenhouse gas kinetics of the atmosphere of Earth. Further, it has been found that methane is a source of significant infrared absorption in the atmospheres of Jupiter, Saturn, Uranus and Neptune [1].

In the present study, our aim is to carry out ab initio calculations for the vibrational elastic, rotationally summed cross sections of the CH4 molecules with exact static-exchange-polarization (SEP) contributions using close coupling scheme for vibrational motion in the low energy region 1 – 30 eV. Calculations have been performed by many researchers who tested their approach with the experimental measurements. Shyn and Cravens [2] reported experimental measurements for the differential (vibrationally) cross sections of CH4 molecules by electron impact using modulated crossed-beam method. Almost at the same time, Boesten and Tanaka [3] have also measured differential, integral and momentum transfer cross sections using a crossed beam spectrometer for impact energies from 1.5 – 100 eV. Lima et al [4,5] calculated differential cross sections using Schwinger multichannel (SMC) method at the static-exchange (SE) level and the static-exchange-plus-polarization (SEP) level respectively. Similarly, McCurdy and Rescigno [6] performed complex Kohn variational (CVK) calculations for partial cross sections in the A1, T2, and E symmetry at the SE level. It is interesting to note that most of the computational methods still show discrepancies with the experimental method. This may be due to the choice of correct potentials.

In view of this, the first step of our calculation is to generate the total electron-molecule interaction potential which is sum of three local and real terms, namely, the static Vst(r), the exchange Vex(r) and the polarization Vpol(r) potential. All the three potential terms, i.e., Vst(r), Vex(r) and Vpol(r) are functions of the electronic charge density ρ(r) of the target. We determine ρ(r) from single-centre wavefunctions with enough terms in the expansion of each bound orbital. The quantity ρ(r) is expanded in terms of symmetry-adapted functions belonging to the totally symmetric 1A1 irreducible representation of the molecular point group. Explicit expression for Vst(r) is given in the literature (see, for example, Gianturco and Jain [7]). We have used modified semi classical exchange (MSCE) form of Vex(r) taken from Gianturco and Scialla [8]. Finally, the correlation polarization potential (COP) for the e – CH4 system is calculated from the expression given in the literature by Padial and Norcross [9]. At larger distances the COP [i.e., Vpol(r)] is replaced by the correct asymptotic form - α0/2r4 (α0 is the dipole polarizability of CH4; we employ the experimental value of 17.5 au for α0).

We have calculated differential and integral cross sections for the CH4 molecules. Fig. 1 shows differential cross section at 10 eV. Results are compared with the measurements of Shyn and Cravens [2] and Boesten and Tanaka [3]. Present calculated results are in good agreement with the measurements of Boesten and Tanaka [3] compared to the calculations of Lima et al [4]. The detailed results will be presented and discussed during the conference. References [1] A. L. Broadfoot, F. Herbert, J. B. Holberg, D. M. Hunten, S. Kumar, B. R. Sandel, D. E. Shemansky, G. R. Smith, R. V. Yelle,

D. F. Strobel, H. W. Moos, T. M. Donahue, S. K. Atreya, J. L. Bertaux, J. E. Blamont, J. C. McConnell, A. J. Dessler, S. Linick, R. Springer, Science 233 (1986) 74.

[2] T. W. Shyn, T. E. Cravens, J. Phys. B.: At. Mol. Opt. Phys. 23 (1990) 293. [3] L. Boesten, H. Tanaka, J. Phys. B.: At. Mol. Opt. Phys. 24 (1991) 821. [4] M. A. P. Lima, T. L. Gibson, W. M. Huo, V. McKoy, Phys. Rev. A 32 (1985) 2696. [5] M. A. P. Lima, K. Watari, V. McKoy, Phys. Rev. A 39 (1989) 4312. [6] C. W. McCurdy, T. N. Rescigno, Phys. Rev. A 39 (1989) 4487. [7] F. A. Gianturco, A. Jain, Phys. Rep. 143 (1986) 347. [8] F. A. Gianturco, S. Scialla, J. Phys. B 20 (1987) 3171. [9] N. T. Padial, D W Norcross, Phys. Rev. A 29 (1984) 1590.

Fig. 1. Differential cross sections for e – CH4 at 10 eV. Calculations: black solid line, present results; magenta dashed line, Ref. [4]. Experimental data: red solid circle, Ref. [3]; blue open circle, Ref. [2].


168

Getting to the ‘guts’ of plastic pollution: identification of ingested polymers J. E. HALSTEAD1*, E. A. CARTER2, J.A. SMITH1, M. A. BROWNE1,2, E. L. JOHNSTON1

1UNSW School of BEES, Randwick, 2052, NSW, Australia 2Vibrational Spectroscopy Core Facility, The University of Sydney, Madsen Building F09, Camperdown, 2006, NSW, Australia [email protected]

Plastic is a persistent, bioaccumulative and toxic contaminant found in habitats worldwide. Although ingestion of plastic debris is well documented in open-ocean organisms, little is known about the risk to recreationally and commercially important fishes that forage in coastal habitats contaminated by major sources of plastic debris, such as major coastal cities. In Australia, over 85% of the population is situated in coastal regions, and as such, Sydney Harbour estuaries are likely to be sinks for mismanaged plastic debris transported via storm water drains, effluent and wastewater.

In order to establish if coastal marine populations are at significant risk of ingesting plastic debris, we used vibrational spectroscopy to quantify ingested plastic in multiple species of fish (Gerres subfasciatus (Silver Biddy), Mugil cephalus (Sea Mullet) Acanthopagrus australis (Yellowfin Bream) and Sillago ciliata (Sand Whiting)) from Sydney Harbour. We then examined relationships between the debris and different species and size of fish, and their diet. Through this we developed novel spectroscopic techniques to quantify ingested plastic by differentiating between synthetic and natural-based fibres, and were also able to highlight the significant problems plastic additives can cause in the classification of polymers using spectral analysis.

Figure 1 depicts the Raman spectra collected from a fragment of blue plastic. The spectra exhibit different spectral features when interrogated with a variety of excitation wavelengths. This is attributed to a resonance enhancement of the blue dye in the fragment. These differences highlight the need to apply comprehensive spectroscopic techniques when identifying micro plastic particles. Acknowledgement This research was funded by an Australian Research Council grant awarded to ELJ, EAC and MAB. We would like to thank Derrick Cruz for his assistance in the field.

Fig. 1. Raman spectra from a blue fragment collected with A) 488 nm B) 514 nm C) 633 nm D) 785 nm E) 830 nm excitation lines.

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169

Analysis of Cocaine Analogues Impregnated into Textiles by Raman Spectroscopy L. XIAO1*, M. SUDEN1, N. KRAYEM1 AND S. FU1

1Centre for Forensic Science, School of Chemistry and Forensic Sciences, University of Technology Sydney, PO Box 123, Broadway, 2007, NSW, Australia [email protected]

To keep up with the dynamic and changing market of illicit drugs, it is important not only to utilise and adapt existing analytical methods, but also to develop new ones that allow speedy determination of these controlled substances.

We aimed to explore the feasibility of developing Raman spectroscopic method for the speedy determination of illicit drugs in various matrices. One example of cocaine trafficking through international borders is textile impregnation. Clothing is impregnated with cocaine in solution and then packed into luggage. The study aimed to produce a one size fits all standard curve that could quantify cocaine analogues concentrations in various types of textiles. Textiles were impregnated using solutions of cocaine analogues as shown in Figure 1 in methanol and the impregnated cocaine analogue was extracted with acidified water followed by addition of potassium thiocyanate as internal standard. The sample preparation was fast and Raman analysis could be performed in a timely manner. The method was validated over a concentration range of 1.25-75 mg/cm2 with a coefficient of determination R2=0.992 for the linearity, and the accuracy and precision values were well within the recommended value of RSD<20%. There were also variations across different textiles which could be due to interferences from dyes.

Figure 1. Chemical structures of atropine (left) and cocaine (right)

References [1] Illicit Drug Data Report 2009-10, Australian Crime Commission (ACC). [2] World Drug Report 2012, United Nations Office on Drugs and Crime (UNODC). E.M.A. Ali, H.G.M. Edwards, M.D.

Hargreaves & I.J. Scowen 2010, 'In situ detection of cocaine hydrochloride in clothing impregnated with the drug using benchtop and portable Raman spectroscopy', Journal of Raman Spectroscopy, (41) 9, 938-43.

[3] E.M.A. Ali, H.G.M. Edwards & I.J. Scowen 2011, 'Rapid in situ detection of street samples of drugs of abuse on textile substrates using microRaman spectroscopy', Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, (80)1, 2-7.

[4] M. West & M. Went 2011, 'Detection of Drugs of Abuse by Raman Spectroscopy', Drug Testing and Analysis, (3) 9, 532-8. [5] B. Sägmüller, B. Schwarze, G. Brehm, G. Trachta & S. Schneider 2003, 'Identification of illicit drugs by a combination of liquid

chromatography and surface-enhanced Raman scattering spectroscopy', Journal of Molecular Structure, (661–662), 279-90. [6] E.L. Izake 2010, 'Forensic and homeland security applications of modern portable Raman spectroscopy', Forensic Science

International, (202)1–3, 1-8 [7] S. McDermott & J. Power 2005, 'Drug Smuggling Using Clothing Impregnated with Cocaine', Journal Of Forensic Science, (50)

6, 1423-5.


170

Vibrational spectroscopic methods to identify and quantify adulterants in weightloss herbal medicines J. S. ROONEY1*, A. MCDOWELL2, C. J. STRACHAN2, 3 AND K. C. GORDON1

1Department of Chemistry, University of Otago, Union Place West, Dunedin, 9016, New Zealand, email: [email protected] 2School of Pharmacy, University of Otago, 18 Frederick Street, Dunedin, 9016, New Zealand 3Faculty of Pharmacy, University of Helsinki, Helsinki, 00790, Finland

Since the 1970s, unlisted pharmaceuticals have regularly been discovered in herbal medicines mainly originating from China and South America [1]. Adulterants commonly found include analgesics, antibiotics, hypoglycaemics, steroids, psychotropics, anorectics and erectogenics [2-4, 7]. Detection and confirmation of these herbal medicine adulterants involves HPLC, LC-MS and GC-MS. These techniques are time-intensive, labour-intensive, destructive and present high running costs. Consequently screening of herbal medicines is not routinely performed by the majority of regulatory bodies [5-7]. Seizures occur when there are international alerts on brands or when physicians report adverse events [6, 7].

MIR, NIR and Raman spectroscopic techniques are rapid, low-cost and non-destructive, which have the potential to permit high throughput screening with nominal accuracy sacrificed. These advantages were utilised in this research project to identify and semi-quantify adulterants commonly found in seized weightloss herbal medicines which were provided by Medsafe New Zealand [7]. The adulterants of interest were the two withdrawn anorectics sibutramine HCl·∙H2O and fenfluramine HCl as well as the withdrawn laxative phenolphthalein. An HPLC methodology was developed and validated to provide reference data for the principal component analysis (PCA) and partial least squares (PLS) models.

A total of 38 product brands were used in the study (each in triplicate). Sibutramine was the sole adulterant in 15 products while only 4 products had phenolphthalein as the sole adulterant. Both these adulterants were simultaneously present in 9 products while 10 products were unadulterated. The concentration range for sibutramine was 1.7-11.7% (x ̅ = 5.8%, s = 3.1%) and the concentration range for phenolphthalein was 0.9-34.4% (x ̅ = 16.9%, s = 9.6%). Eleven products had sibutramine doses in excess of the former maximum therapeutic daily dose and therefore would pose a significant danger to consumer health [7].

Raman proved unsuitable due to strong emission and sample burning even when the 1064 nm laser was defocused. In contrast, PCA models were able to be constructed from training sets using the MIR and NIR data. These two models showed separation of the adulterated and unadulterated samples, which was reflected in their respective loadings plots. Test set projections demonstrated the PCA models had predictive utility. Nonetheless, the NIR model showed relatively poor distinction between samples adulterated with sibutramine and phenolphthalein which was explained by the similar absorptions between the two adulterants in the NIR spectral region.

PLS models were constructed from the training sets and then validated by prediction of the test sets. MIR afforded the best performances based on three and one factors for the sibutramine and phenolphthalein models respectively. The root mean squared error of calibration and prediction (RMSEC and RMSEP) were both 0.8% for sibutramine. For the phenolphthalein model the RMSEC and RMSEP were 2.1% and 2.2% respectively. The weighted loadings and regression coefficients demonstrated predictions were based on the absorption bands of the respective adulterant. Figure 1a and b shows the test set prediction results for the sibutramine and phenolphthalein models respectively. These results show ample performance for semi-quantification of the adulterants to gauge the level of consumer risk. References [1] S. Mills, K. Bone, The Essential Guide to Herbal Safety; Churchill Livingstone: Missouri (2008), 106-118. [2] U. Garg, A. M. Ferguson, Herbal Supplements; John Wiley & Sons: New Jersey (2011), 369-386. [3] E. Sanzini, M. Badea, A. D. Santos, P. Restani, H. Sievers, Food Funct. 2 (2011), 740-746. [4] A. Debella, D. Abebe, K. Mudie, A. Tadele, A. Gebreegziabher, Ethiop. J. Health Dev. 22 (2008), 55-62. [5] H. Ataera Medsafe New Zealand, Personal Communication (2014). [6] Food and Drug Administration, http://www.fda.gov/Food/DietarySupplements/QADietarySupplements/default.htm (2015). [7] J. S. Rooney, A. McDowell, C. J. Strachan, K. C. Gordon, Talanta 138 (2015), 77-85.

Fig. 1. Sibutramine (a) and phenolphthalein (b) test set predictions using their respective MIR PLS model. Bars indicate the similarity of the sample to the average training set sample [7].


171

Raman Mapping of Two Metal Ligand Co-crystals L. RINTOUL1*, A. WORTHY1, K. FISHER1, J. BOUZAID1, AND J. MCMURTRIE1

1Queensland University of Technology, GPO Box 2434, Brisbane, 4001, QLD, Australia [email protected]

An important goal of crystal engineering is the synthesis of multifunctional crystalline materials with predictable structural architectures and tunable solid-state properties [1]. To this end we have been studying the co-crystallisation of binary mixtures of transition metal complexes that differ by metal ion and/or coordinating ligand but are isomorphous in crystal structure, as well as more complex systems where the pure components have generally similar molecular formulas but differ in crystal structure.

Starting with simple isomorphous systems, we grew crystals from solutions of various mole fractions of [MA(ligand)n]X2 + [MB(ligand)n]X2 where MA, MB = different 1st or 2nd row transition metals and X = a monoanion eg PF6

-. Commonplace ligands such as terpy, phen or bipy or substituted variants of these have been used. Typically we obtained: 1) crystals of one or both of the pure complexes; 2) co-crystals where the mole fraction is the same as that of the initial solution; or 3) co-crystals in which the mole fraction differs from that of the initial solution. Some crystals of the latter group, in particular those from a 50:50 solution of K3[Fe(ox)3].2.5H2O + K3[Cr(ox)3].2.5H2O where ox= oxalate, not only differed in mole fraction from the initial solution and from each other, but also showed a concentration gradient from crystal centre to surface and indeed on the surface itself.

The wavenumber of the Raman active C=O stretch of the oxalato ligand is somewhat sensitive to the nature of the bound metal ion, shifting from 1723.0 cm-1 in the pure Fe complex to 1727.5 cm-1 in the pure Cr complex. In a previous study [2] we exploited this wavenumber shift to semi-quantitatively determine the Fe/Cr concentration not just of each single co-crystal but also to map any concentration gradients that occur within or on the surface of the crystal. SEM-EDX measurements of [Fe]/[Cr] performed on the same crystal, confirmed the Raman results, albeit destructively.

In a similar experiment we mixed bis(acetylacetonato)copper and palladium, [Cu(acac)2, and Pd(acac)2] in a 60:40 ratio and grew co-crystals that according to SEM-EDX measurements also exhibited metal ion concentration gradients on the surface. Single crystal XRD measurements showed that the unit cell dimensions of the Cu/Pd co-crystals were intermediate between that of the two pure parent complexes as expected.

The Raman spectra of the parent complexes have broadly similar profiles but significant differences do occur in modes with metal-ligand stretching character. The strongest of these bands occurs at 463 cm-1 in the Pd and 451 cm-1 in the Cu complex. In the Cu/Pd co-crystal both bands were observed and their relative intensity appeared to reflect the relative concentration of the two metal ions. This behaviour contrasts strongly with that found earlier in the K3[Fe/Cr(ox)3] 2.5[H2O] systems where only a single oxalato C=O stretch was observed which shifted according to Fe/Cr concentration. This paper will explore this apparent anomaly. Acknowledgement Some of the data reported in this paper were obtained at the Central Analytical Research Facility operated by the Institute for Future Environments (QUT). Access to CARF is supported by generous funding from the Science and Engineering Faculty (QUT). References [1] D. Braga, F. Grepioni, G.R. Desiraju, Chem. Rev., 98 (1998), 1375-1405. [2] J. Bouzaid, Supramolecular Selection in Molecular and Framework Co-Crystals. Ph.D thesis, Queensland University of

Technology (2014).

Fig. 2. Relative intensity variations as a function of position on a Cu/Pd(acac)2 co-crystal

Fig. 1. Comparison of C=O stretch positions of pure K3[Cr(ox)3]·2.5H2O (green), its Fe analogue (blue) and that of a mixed co-crystal (red).


172

Raman spectroscopic study of inclusions in precious opals offer insights into Martian-like weathering processes G. E. ROBERTS1,2, P. F. REY1 AND E. A. CARTER1

1The University of Sydney, Sydney, 2006, NSW, Australia [email protected] 2Dr. Eduard Gübelin Associated for Research and Identification of Precious Stones, Maihofstrasse 102, Lucerne, 6006, Switzerland

Spectral signatures of the surface of Mars indicate a variety of hydrated minerals, including Al- and Fe/Mg-rich phyllosilicates, iron oxides, sulfates, and opaline silica. Their formation has been attributed to a long-lived low-temperature aqueous weathering history [e.g. 1, 2] followed by a period of intense acidic oxidative weathering [e.g. 3]. Very acidic weathering, driven by volcanic-derived sulfuric acid, is possible on a regional scale on Mars because of the lack of carbonate. On Earth, however, low-pH weathering on a regional scale is unusual because of the abundance of carbonate. Finding regional-scale Martian analogues on Earth is therefore a challenge.

The Great Artesian Basin (GAB) in central Australia formed during the Early Cretaceous from the deposition of pyrite-rich volcaniclastic sediments in a cold, muddy, anoxic and shallow continental sea. Following mid-Cretaceous sea regression, a deep (~100 m) weathering profile recorded a protracted episode (from 97 to 60 Ma) of acidic oxidative weathering during continuous uplift and denudation, which stopped 60 myr ago. Since then, the weathering profile, which consists of Al- and Fe-rich phyllosilicates, iron oxides, and sulfates, has been constantly reworked. Interestingly, this profile hosts the bulk of the world’s precious opal deposits. Since no opal deposit can be found in post-60 Ma rock formations, it is most likely that opal is part of the weathering profile developed during the drying out of central Australia.

We are employing a variety of techniques to constrain the Martian-like conditions at the time of opal formation. Utilising Raman spectroscopy, we are documenting minerals found within opal veins from across the GAB. Goethite is commonly found in the vein wall and sulfates such as alunite and gypsum have been documented as being closely related to opal [e.g. 4, 5]. This mineralogical assemblage indicates acidic oxidative conditions prevailed at the time of opal formation, suggesting Martian-like acidic weathering at the scale of the GAB. We propose that the acidity was derived from the oxidation of biogenic pyrite, and that the quasi absence of carbonates allowed very acidic conditions to take hold at a regional scale. If this model is valid, central Australia may be one of the best terrestrial analogues for the understanding of some of Mars’ weathering processes. Acknowledgement This project has been possible thanks to the Dr. Eduard Gübelin Research Scholarship 2014. References [1] J. L. Bishop, E. Z. Noe Dobrea, N. K., McKeown, M. Parente, B. L. Ehlmann, J. R., Michalski, R. E. Milliken, F. Poulet, G. A., Swayze, J. F. Mustard, S. L. Murchie, J.-P. Bibring. Science 321 (2008), 830-833. [2] B. L. Ehlmann, G. Berger, N. Mangold, J. R. Michalski, D. C. Catling, S. W. Ruff, E. Chassefière, P. B. Niles, V. Chevrier, F.

Poulet. Space Sci. Rev. 174 (2013), 329-364. [3] J. Carter, F. Poulet, J.-P. Bibring, N. Mangold, S. Murchie. J. Geophys. Res – Planet 118 (2013), 831-858. [4] M. Liesegang, R. Milke. Am. Mineral 99 (2014), 1488-1499. [5] M. Thiry, J.-M. Schmitt, V. Rayot, A. R. Milnes. C.R. Acad. Sci. Paris 320 (1995), 279-285.


173

The current of the QDIP with illumination H.LIU1,2*, C. YANG1,2

1 Institute of Solid State Physics, Shanxi Datong University, Datong City, ShanXi Province,037009,China; [email protected] 2Higher Education Key Laboratory of New Microstructure function materials�Shanxi Datong University�in Shanxi Province, Datong, 037009, China;

Quantum dot infrared photodetector(QDIP) is a novel quantum dot nano-structure detector, and shows some superior properties for example the low dark current, the high photocurrent, the large responsivity. These performance parameters common determine the detectivity ability of the detector, and attract a wide attention in recent year. In 2001, a device model of the QDIP is proposed by V. Ryzhii and his co-workers by considering the continuous potential distribution of the electrons and the thermal emission[1], and then this device model of the QDIP is improved by thinking about tunnelling emission of the electrons[2] and it is used to calculate the current of the QDIP with illumination. In 2012, the microscale electron transport and the nanoscale electron transport are further included in the performance model of the QDIP to increase the accuracy of the photocurrent[3]. Based on these work above, our paper build the photocurrent model of the QDIP to increase the calculation precision. Specifically, firstly, the dark current model is obtained by the considering the microscale transport, the nanoscale transport, and the drift motion of the electrons based on the Monte Carlo method; secondly, the dark current balance equation is built with the consideration of the above dark current and the continuous potential distribution of the electrons, finally, according to photoconductive mechanism of the QDIP, the photocurrent expression can be obtained by solving the dark current equation above. Here, the photoconductive gain strong depends on the capture behaviour of the electrons, and the absorption coefficient is form the traditional quantum otto cycle. Corresponding calculated results are given and they can provide the device designers with the theoretical guiding for the devices optimization.

Acknowledgement This work was supported by the National Natural Science Foundation of China (NSFC, Grant No. 61307121); Launching Scientific Research Funds for Doctors (Grant NO. 2012-B-04). References [1] V. Ryzhii, I. Khmyrova, V. Pipa, V. Mitin, and M. Willander. Semiconductor Science and Technology.16(2001), 331-338. [2] P. Martyniuk, A. Rogalski. Bulletin the Polish Academy of Sciences: Technical Scinences. 57(2009), 103-116. [3] H.Liu, J.Zhang. Infrared physics and Technology. 55(2012),3320-3325.


174

3D-FDTD Simulation of the Gold urchin-like nanopartilces for the spectral properties of Localized Surface Plasmon Resonance C. F. TIAN1, P. WANG1, T.Y. XIE1, Z. X. GAO1 AND J. X. FANG2

1School of Physics and Electronic Science, Shanxi Datong University, Datong, 037009, Shanxi, China [email protected] 2School of Science, Xi’an Jiaotong University, Xi’an, 710049, Shannxi, China

Localized surface Plasmon resonance (LSPR) arises from the collective oscillation of conduction band electrons of noble metal nanoparticles induced by the interaction with the incident light. LSPR is sensitive to the configuration of metal nanoparticles. Thus, how to precisely design the metal nanostructures and analyze the unique optical and photonic phenomena are important to the applications, such as SERS, plasmonic trapping, plasmon-enhanced fluorescence, two-photon photoluminescence and photo-thermal transduction.[1]

Recently, many researchers have fabricated diverse nanostructures with the chemical or physical method. In this way, we found that the nanostructures with rich nanotips and nanogaps could extremely improve the sensitivity. For example, the single hollow Au-Ag alloy nanourchin was composed with many nanotips and nanogaps ~ 1500 µm–2 and showed high sensitivity (109) in SERS.[2] Additionally, the results of the FDTD calculation further confirmed the relationship between the high sensitivity and the rich nanotips. However, there still have some questions about the physical mechanism.

In this work, we analyzed the spectral properties of Au urchin nanostructures with FDTD method by controlling the size, the distribution of nanotips, polarization and background index. As a result, the determination of the relation between the resonance peak and the fine structures, especially in the changed structures from the same nanoparticle, may help to explain the photo-thermal transduction and guide the nanostructural fabrication to the favorable direction.

Acknowledgement This work was supported by the National Natural Science Foundation of China. (Nos.11304188 and 5117139) References [1] H. Yuan, J. Register, H. –N. Wang, A. Fales, Y. Liu, T. Vo-Dinh, Anal. Bioanal. Chem. 405 (2013), 6165-6180. [2] Z. Liu, Z. B. Yang, B. Peng, C. Cao, C. Zhang, H. J. You, Q. H. Xiong, Z. Y. Li, J. X. Fang, Adv. Mater. 26 (2014), 2431-2439.

Fig. 1. The scattering spectroscopy and electric field intensity distributions of one single Au urchin nanoparticle in air.


175

In situ monitoring and detecting catalytic reaction with surface-enhanced Raman scattering Q. Y. HAN1*, C. Y. ZHANG1, L. X. YAN1, Z. L. ZHANG1, E. J. HE1, J. DONG1, Z. J. WANG1 AND H. R. ZHENG1 1School of Physics and Information Technology, Shaanxi Normal University, 710062, Xi’an, China e-mail. [email protected]

Metal nanocrystals have potential applications in the field of catalysis and spectroscopy [1-2]. In current work, Au-Ag alloy nanoparticles that exhibits strong synergistic effect in plasmonic and catalytic activity were synthesized, which could overcome significantly limiting condition including stability, sizes, and structure models of samples. Meanwhile, the in situ SERS monitoring of the catalytic reactions with plasmonic metal nanostructures was investigated experimentally. The siganls representing the intermediate reaction processes were detected with high sensitivity, and were clearly identified with in situ SERS spectroscopy. The result of the current study may provide a promising technique for heterogeneous catalysis research.

Acknowledgement The work is supported by the National Science Foundation of China (Grant 11174190), the Fundamental Research Funds for the Central Universities (Grants GK201504005), the Natural Science Foundation of Shaanxi Educational Committee (No.2013JK0627) and the Natural Science Basis Research Plan in Shaanxi Province of China(Program No.2013JM1008). References [1] J. Dong, S. X. Qu, Z. L. Zhang, M. C. Liu, G. N. Liu, X. Q. Yan, H. R. Zheng, J. Appl. Phys. 111(2012), 093101 (1-3). [2] Z. L. Zhang, T. Deckert-Gaudig, P. Singh, V. Deckert, Chem. Commun. 51(2015), 3069-3072.

Fig. 1. A tentative mechanism of the chemical reduction of surface-adsorbed 4-NTP by NaBH4 to DMAB, and finally to 4- ATP catalyzed by Au-Ag alloy NPs.


176

Infrared characterisation of calixarene-polymer composite materials for surface modified ATR waveguides C. H. HEATH1*, B. PEJCIC1 AND M. MYERS1

1CSIRO, Energy Flagship, 26 Dick Perry Ave, Kensington, 6151, WA, Australia, [email protected]

Surface modified ATR waveguides have attracted significant interest due to their potential as a sensor platform for the environmental monitoring of hydrocarbons in water at low concentrations [1]. The surface coating material is critical for the analytical performance of the ATR waveguide. This generally comprises a polymer which is able to partition the species of interest into the evanescent field and exclude other substances that would lead to interfering effects. In an effort to improve the analytical properties of our chemical sensors we are investigating new materials such as polymer-cavitand hybrids. Calixarenes are container shaped molecules which are known to interact and bind with a variety of small molecules such as hydrocarbons through host-guest interactions. They have the potential to improve the limit of detection and selectivity of hydrocarbon sensors. In addition, the strong binding may causes frequency shifts in the absorption bands of the analytes due to their strong host-guest interaction and help improve molecular discrimination. The characterization of novel hybrid materials has been performed using infrared spectroscopy, particularly with respect to understanding the interactions between the cavitand and polymer materials. References [1] Pejcic B, Myers M, Ross A, Mid-infrared sensing of organic pollutants in aqueous environments, Sensors, 2009, 9(8), 6232-6253, [2] (a) Rebek, J. J., Chemical Communications 2000, (8), 637-643; (b) Böhmer, V., Angewandte Chemie International Edition in English 1995, 34 (7), 713-745.

Fig. 1. A cavitand molecule 4-tert-Butylcalix[6]arene capable of binding hydrocarbons.


177

Halogen Bonding Assisted Formation of Supramolecular Helical Structure with Chiral Amplification J. L. CAO1*, Y. B. JIANG1

1Department of Chemistry, College of Chemistry & Chemical Engineering, Xiamen University, Xiamen 361005, China. E-mail: [email protected]

In the past decade, great effort has been devoted to the construction of supramolecular helical polymers because of their diversity and potential applications in developing of new materials, in which non-covalent interactions, such as electrostatic, hydrogen bonding, hydrophobicity, π…π interaction, Van der Waals' force and metal-metal interaction have been utilized as the driving forces.[1] Recently, halogen bonding was brought into attention as a novel non-covalent interaction.[2-5] However, application of halogen bonding in solution-phase self-assembly remains underdeveloped. This motivated us to explore halogen bonding as another driving force for supramolecular helical structures.

Short peptide based N-amidothioureas were recently developed in our laboratory, in which β-turn structures and the induced chirality transfer were demonstrated.[6] Here we exploited a series of alanine based bilateral N-amidothioureas with halogen atoms (F, Cl, Br, I) substituted at the para-position of the phenyl rings. Circular dichroism (CD) spectra of the compound bearing a p-I in acetonitrile (Fig.1) exhibited different character from those of other halogen substituted compounds, suggesting the formation of supramolecular helical structures, which was verified by the concentration and temperature effects. Indeed, helical structures for p-I (right-handed for L-alanine and left-handed for D-alanine) were observed in scanning electron microscope (SEM) images, while a small quantity of similar helical structures were also displayed for p-Br, but only particle morphology for p-F and p-Cl compounds under the same conditions. In addition, mass spectra (MS) and dynamic light scattering (DLS) also suggested the formation of stable supramolecular polymers for p-I, while not so stable for p-Br and no polymers for p-F and p-Cl compounds. Most importantly, obvious chiral amplification was observed in the major rule experiment only for the p-I compound, supporting the formation of supramolecular helical assembly that is assisted by strong I…I halogen bonding.[7-8]

Acknowledgement We acknowledge financial supports from the MOST (grant 2011CB910403), the NSF of China (grants 91127019, 21275121, and 21435003), and the Program for Changjiang Scholars and Innovative Research Team in University, administrated by the MOE of China (grant IRT13036). References [1] P. Metrangolo, F. Meyer, T. Pilati, G. Resnati, G. Terraneo, Angew. Chem. Int. Ed. 47 (2008), 6114-6127. [2] P. Metrangolo, H. Neukirch, T. Pilati, G. Resnati, Acc. Chem. Res. 38 (2005), 386-395. [3] A. R. Voth, P. Khuu, K. Oishi, P. S. Ho, Nat. Chem. 1 (2009), 74-79. [4] D. A. Smith, L. Brammer, C. A. Hunter, R. N. Perutz, J. Am. Chem. Soc. 136 (2014), 1288-1291. [5] M. J. Langton, S.W. Robinson, I. Marques, V. Felix, P. D. Beer, Nat. Chem. 6 (2014), 1039-1043. [6] X. S. Yan, K. Wu, Y. Yuan, Y. Zhan, J. H. Wang, Z. Li, Y. B. Jiang, Chem. Commun. 49 (2013), 8943-8945. [7] N. Ramasubbu, R. Parthasarathy, P. Murray-Rust, J. Am. Chem. Soc. 108 (1986), 4308-4314. [8] F. Zordan, L. Brammer, P. Sherwood, J. Am. Chem. Soc. 127 (2005), 5979-5989.

Fig. 1. CD spectra of L,L-PATU-p-X in acetonitrile, [L,L-PATU-p-X] = 10 µM.


178

Polymer Recycling C. F. KONG, PerkinElmer, Australia

The use of post-consumer recycled polymers, a Green and cost-effective alternative to virgin polymers, has been growing steadily over recent years. Across the world there are initiatives for consumers to increase the amount of materials they recycle rather than discard them to landfills. However, in order to be recycled successfully, plastics need to be identified accurately and sorted accordingly. This presentation highlights the use of FTIR, DSC and TGA techniques to identify polymer form, polymer mixtures and additives.


179

β-Turn Based Ratiometric Fluorescent Beacon Receptor for Anion Y. YUAN1*, X. S. YAN1 AND Y. B. JIANG1

1Department of Chemistry, College of Chemistry & Chemical Engineering, Xiamen University, Xiamen 361005, China. e-mail: [email protected].

We recently reported the two terminus (R1 and R2) in the β-turn structure are brought into close proximity in a pseudo-parallel conformation.[1] We thus envisaged that incorporating a target binding site within the turn structure while attaching fluorophore/quencher at the two terminus would lead to a peptide beacon (PB). Herein reported is a proof-of-concept investigation for developing short peptide based PBs that contain a turn structure, by attaching two pyrene fluorophores (L-/D-1, Figure 1) or a pyrene fluorophore and dimethylaniline (L-/D-3, Figure 1) respectively at the two terminus of the β-turn structure, in a hope of employing pyrene excimer[2-7] or exciplex[8] dual emission as sensing signals. In the presence of anion the dual fluorescence undergoes a sensitive change in terms of the intensity ratio, affording indeed a ratiometric fluorescent sensing protocol (Figure 1).

It is known that the thioureido -NHs in the turn structure exist in trans-configuration, whereas upon binding to oxoanions such as acetate anion they should assume a cis-configuration.[9-11] Therefore a configuration change was expected in the turn structure upon its binding to anion and hence a change in the dual emission, allowing for fluorescent sensing of anion in a fashion similar to that of nucleic acid MBs.

Dual emission characteristic of pyrene excimer was indeed observed with L-1, in which the short-wavelength and structured emission between 350-440 nm originates from pyrene monomer while the long-wavelength broad emission centred at 475 nm is assigned to the excimer.[2-7] We next examined the response of the dual emission of L-1 and D-1 toward model anions such as acetate and fluoride that bind to the amidothiourea moiety[9-11] within the turn structure. Figure 1 shows traces of fluorescence spectra of L-1 at 10 µM in acetonitrile in the presence of acetate anion of increasing concentration. Profile for D-1 is practically the same as that of L-1. It is indeed seen that while the monomer emission does not change much the excimer emission is quenched with increasing anion concentration, underlining a decrease in the excimer to monomer intensity ratio and hence establishing a ratiometric response for anion by the beacon receptor. Similar response was also observed for L-1 toward fluoride anion, but at a higher sensitivity, which agrees with the higher binding affinity for fluoride than acetate anion of the thiourea receptor.[9-11] When one pyrenec fluorophore in 1 is replaced by an electron donor, N,N-dimethylaniline (DMA), leading to L-3/D-3, exciplex dual emission was observed, and similarly the dual emission exhibits ratiometric response toward anions.

The turn structure in short peptides thus represents a new structural platform for creating peptide beacons that have not yet been well explored since normal short peptides may not take such a folded structure that undergoes a configurational change that can be signaled. Acknowledgement We acknowledge financial supports from the MOST (grant 2011CB910403), the NSF of China (grants 91127019, 21275121, and 21435003), and the Program for Changjiang Scholars and Innovative Research Team in University, administrated by the MOE of China (grant IRT13036). References [1] X.-S. Yan, K. Wu, Y. Yuan, Y. Zhan, J.-H. Wang, Z. Li, Y.-B. Jiang, Chemical Communications 2013, 49, 8943. [2] K. A. Zachariasse, A. L. Maçanita, W. Kühnle, The Journal of Physical Chemistry B 1999, 103, 9356. [3] S. Nishizawa, Y. Kato, N. Teramae, Journal of the American Chemical Society 1999, 121, 9463. [4] M. H. Filby, S. J. Dickson, N. Zaccheroni, L. Prodi, S. Bonacchi, M. Montalti, M. J. Paterson, T. D. Humphries, C. Chiorboli, J.

W. Steed, Journal of the American Chemical Society 2008, 130, 4105. [5] S. Chen, L. Wang, N. E. Fahmi, S. J. Benkovic, S. M. Hecht, Journal of the American Chemical Society 2012, 134, 18883. [6] Y.-J. Huang, W.-J. Ouyang, X. Wu, Z. Li, J. S. Fossey, T. D. James, Y.-B. Jiang, Journal of the American Chemical Society

2013, 135, 1700.

[7] Y. Liu, E. J. Jun, G. Kim, A.-R. Lee, J.-H. Lee, J. Yoon, Chemical Communications 2014, 50, 2505. [8] I. Alfonso, M. I. Burguete, F. Galindo, S. V. Luis, L. Vigara, The Journal of Organic Chemistry 2009, 74, 6130. [9] P. A. Gale, Chemical Society Reviews 2010, 39, 3746. [10]R. M. Duke, E. B. Veale, F. M. Pfeffer, P. E. Kruger, T. Gunnlaugsson, Chemical Society Reviews 2010, 39, 3936. [11] A.-F. Li, J.-H. Wang, F. Wang, Y.-B. Jiang, Chemical Society Reviews 2010, 39, 3729.

Figure 1. Fluorescence spectra of L-1 in acetonitrile in the presence of acetate anion of 0 to 2.5 eq. [L-1] = 10 µM.


180

REMPI Spectroscopy of Toluene+H. Hydrogenation and Deuteration effects on Methyl Rotor O. KRECHKIVSKA1*, K. NAUTA1, K. L. K. LEE1, Y. LIU1, S. H. KABLE1, T. W. SCHMIDT1 1School of Chemistry, UNSW, Sydney, NSW 2052, Australia

Methyl rotor structure in toluene, halogenated toluenes, anthracene, etc, received a lot of attention during past

decades.1 We investigate this common scientific problem for a completely new system, Toluene+H, where Hydrogen/Deuterium addition to ortho- position of toluene was achieved for the first time. Spectra and ionization energies of toluene+H/D, toluene D3+H/D and toluene D8+H/D were obtained by means of the Resonance Enhanced Multi Photon Ionization (REMPI) spectroscopy. Toluene+H radicals were produced in the supersonic expansion of argon gas seeded with toluene and water vapor at room temperature, followed by an electric discharge.

REMPI spectra of six toluene+H isotopomers were recorded in the 18200-19200 cm-1 region using Nd-YAG pumped dye laser (Coumarin 540A, Coumarin 503 dyes) for excitation and 266 nm light for ionization. Ionization energies for various isotopomers were obtained by keeping the excitation photon fixed and scanning second, ionization photon (doubled Rhodamine 590 dye).

Hydrogen atom with respect to the methyl group in toluene can add at three different positions, such as ortho-, meta-, and para-, and to investigate all these possibilities we have performed an extensive search in the visible region and employing a wide range of ionization energies. The only region of spectroscopic activity found is mentioned above, and despite all effort we could not detect any resonant signal elsewhere. Within the excitation spectrum for every isotopomer we have measured ionization energies for most intense features in a search of isomers. All ionization energies were found to be identical, this suggested that only one isomer is formed. The ab initio calculations and torsional potentials suggest ortho- isomer. The phenomenon of hydrogen addition exclusively to the ortho position is discussed for phenol+H and toluene+H in our recent paper.2

Fig. 1. Left. Methyl rotor structure of various hydrogenated/deuterated isotopomers of Toluene. Right. Methyl rotor analysis for Toluene+H.

References [1] L.H. Spangler, Annu. Rev. Phys. Chem., 48, 481-510, 1997 [2] C. Wilcox, O. Krechkivska, T.Troy, K.Nauta, T.W.Schmidt and S.H.Kable in preparation


181

Role of Multiple Ionization in L X-ray Fluoroscopic Spectrum of Platinum M. KAUR1,2*, H. MOHAN1, A. K. JAIN1, P. S. SINGH2 AND S. SHARMA3

1Department of Physics, M.L.N. College, Yamuna Nagar, 135 001, Haryana, India [email protected] 2Department of Physics, Punjabi University, Patiala, 147 002, Punjab, India 3Department of Chemistry, M.L.N. College, Yamuna Nagar, 135 001, Haryana, India

Fluorescence yields and Coster-Kronig (C-K) transition probabilities are the important parameters in the study of high resolution spectrum [1]. These are required in analytical methods such as X-ray fluorescence (XRF), particle-induced X-ray emission (PIXE) and electron probe micro-analysis. When these parameters are applied in ion-atom collisions, the multiple ionization (MI) plays an important role. Number of workers [2,3] have studied this effect for heavier ions. But in the case of protons, investigations are still required. In view of this, we examine its (MI) role by computing and measuring the intensity ratios of the L X-ray spectra of Platinum by proton impact.

Lapicki et al [4] suggested a method to modify the fluorescence yields and Coster–Kronig transition probabilities so as to account for multiple ionization effect. This alteration considers a crucial assumption that the fluorescence yields are affected by the formation of holes in the outer shells by the incoming ions, with an equal possibility for each shell. This probability is calculated through the binary encounter approximation [5] keeping away from the lengthy dealing of outer-shell ionization by other quantum or semi classical theories [6]. Deficiency of electrons in multiple ionized atoms reduces both radiative and non-radiative transitions. X-ray rates are less reduced in comparison to the Auger as just one electron is required for X-ray transitions where as Auger transition needs two electrons. An accurate amendment of this yield depends on the comprehensive information of all possible mechanisms that fill an inner shell vacancy and the probability for ionization of the outer shells which are of much concern in these transitions. To simplify many of such transitions, we have corrected the single-hole fluorescence and C-K yields of Campbell [7], ωi

o and fijo using a basic assumption that

each electron in a manifold of outer sub shells is ionized with a probability P.

With all radiative transition widths narrowed by the same factor (1 – P) and with all Auger rates involving two electrons in the manifold of outer states as well as the Coster-Kronig transitions decreased by (1 – P)2. Hence the corrected ωi is given by ωi = ωi

o / [1 – P(1 – ωio)] where as fij = fij

o(1 – P)2. The probability P for ionizing an outer shell electron is calculated according to the equation P = q2 (1 – β / 4υ1

2) / 2βυ12

where β = 0.9 and υ1 = 6.351 [E1 (MeV) / A1 (u)]1/2. Here, υ1 is the projectile velocity in terms of projectile energy E1 and its atomic mass A1. .Applying these

formulations, we have computed the multiple ionization effect for L X-ray fluoroscopic spectrum of Platinum with proton impact in the energy range 260 keV to 400 keV at the interval of 20 keV. The experimental values of these ratios were measured using high purity germanium (HPGe) detector placed at right angle to the beam. The beam current on the target is measured by current integrator .It has high sensitivity, accuracy, low drift and an internal calibrating source. The spectrum consists of four peaks of L X-ray groups corresponding to Lα, Lβ, Lγ and Lℓ which are well separated from each other. The details of the experimental and theoretical methodology can be seen in one of our earlier publications [8]. The comparison of various intensity ratios is illustrated in Fig. 1. In this figure, we have presented Lγ/Lα line intensity ratio calculated for multiple ionization non relativistic (MINR), multiple ionization relativistic (MIR) and without multiple ionization (WMI) along with experimentally measured values. The detailed results will be presented and discussed during the conference. Conclusively, the present work provides an important application in quantitative analysis, where the data are derived from the observed fractional yield of the decay, e.g. X-ray fluoroscopy or Auger electron spectroscopy.

References [1] J. Mirandaa, G. Lapicki, At. Data Nucl. Data Tables 100 (2014) 651. [2] Y. C. Yu, C. W. Wang, E. K. Lin, T. Y. Liu, H. L. Sun, J. W. Chiou, G. Lapicki, J. Phys. B: At. Mol. Opt. Phys. 30 (1997) 5791. [3] J. Semaniak, J. Braziewicz, M. Pajek, T. Czyzewski, L. Glowacka, M. Jaskola, M. Haller, R. Karschnick, W. Kretschmer, Z.

Halabuka, D. Trautmann, Phys. Rev. A 52 (1995) 1125. [4] G. Lapicki, R. Mehta, J. L. Duggan, P. M. Kocur, J. L. Price, F. D. McDaniel, Phys. Rev. A 34 (1986) 3813. [5] D. H. Madison, E. Merzbacher, In: Atomic Inner-Shell Processes, Ed. B. Crasemann, Vol. I (Academic Press, New York, 1975)

1. [6] J. Miranda, O. G. de Lucio, E. B. Tellez, J. N. Martinez, Rad. Phys. Chem. 69 (2004) 257. [7] J. L. Campbell, At. Data Nucl. Data Tables 85 (2003) 291; ibid. 95 (2009) 115. [8] H. Mohan , A. K. Jain, Mandeep Kaur, Parjit S. Singh, S. Sharma, Nucl. Instr. Meth. B 332 (2014) 103.

Fig. 1. Lγ/Lα Line intensity ratios for Platinum as a function of proton energy.


182

MIR-FIR Spectroscopy by a Single Step Data Acquisition A. BALES1, K. TAM1, G. ZACHMANN2, M. KEßLER2 1Bruker Pty Ltd, 7/163-167 McEvoy St, Alexandria, 2015 NSW Australia email: [email protected] 2Bruker Optik GmbH, Rudolf-Plank-Str. 27, 76275 Ettlingen, Germany

The extension of the mid IR towards the far IR spectral range below 400 cm-1 is in general of great interest for molecular vibrational analysis for inorganic and organometallic chemistry, for geological, pharmaceutical, and physical applications, polymorph screening and crystallinity analysis as well as for matrix isolation spectroscopy1-3. In above mentioned areas the additional far infrared region offers insight to low energy vibrations which are observable only there. This includes lattice vibrations or intermolecular vibrations in the ordered solid state.

The achievable spectral range of an FTIR spectrometer is defined by the intersection of the efficiency ranges of the used source, beam splitter and detector. The lower limit of the spectral range is very dependent upon the beamsplitter, and is typically limited to above 350 cm-1. The extension of the IR spectrum further into the far IR and THz spectral range requires a least one additional far IR beamsplitter and detector. Because of this the user has to pause the measurement for automated exchange of the above mentioned optical components4 or if needed, manually open the spectrometer optics bench.

However, from now on for the first time the Bruker VERTEX FM wide range infrared technology, which is available for VERTEX 70 and 70v vacuum FT-IR spectrometers, combines two innovative Bruker optic components: The wide range MIR-FIR beamsplitter and the wide range DLaTGS detector. This new and uniqueVERTEX FM

option5 enables in connection with the standard IR source the spectral range from 6000 cm-1 down to 80 cm-1 (or 50 cm-

1 for VERTEX 70v) in one step for any type of transmittance, reflectance and ATR measurements. This makes data acquisition of a complete mid and far IR spectrum readily useable, guarantees identical measurement conditions for both spectral ranges and saves plenty of time. The spectral range can be ultimately extended even down to 10 cm-1 utilizing the external water cooled mercury arc high power lamp.

In figure 1 an application example of the VERTEX FM functionality is shown with the study of an inorganic filler material in a polymer matrix6. The identification of the filler is made easy due to the additional far infrared region of the one step measurement.

For the identification of inorganics and polymorphs by spectral library data in the far infrared to date there were

only limited options available in form of additional far infrared libraries. Now the VERTEX FM functionality allows for the build-up of outstanding spectral libraries covering the complete MIR-FIR region6. References [1] Bawuah P., Kiss M. Z., Silfsten P., Tak C.-M., Gane P. A. C. and Peiponen K.-E. (2014), Optical Review, 21 (3), 373-377. [2] Strachan C. J., Taday P. F., Newnham D. A., Gordon K. C., Zeitler J. A., Pepper M. and Rades T. (2005), J. Pharm. Sci., 94 (4),

837-846. [3] Bruker Optics Application Note AN127 (2015). [4] Simon A., Zachmann G. (2012), Vibrational Spectroscopy, 60, 98–101. [5] Bruker Optics Application Note AN118 (2014). [6] Bruker Optics Application Note AN123 (2014).

Fig. 1. IR spectra measured with the VERTEX FM functionality of an Acrylonitrile Butadiene Styrene copolymer (ABS) containing three percent of antimony trioxide as filler.


183

Terahertz spectroscopy of a supramolecular assembly: helical fibres of N-acetylated tri-β3-peptides R. S. SEOUDI1*, A. DOWD2, M. DEL BORGO3, K. KULKARNI3, P. PERLMUTTER4, M.-I. AGUILAR3 AND A. MECHLER1

1Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Plenty Road & Kingsbury Drive, Melbourne 3086, VIC, Australia, e-mail. [email protected] 2 School of Physics and Advanced Materials, University of Technology 15 Broadway, Ultimo 2007, Sydney, NSW, Australia

3Department of Biochemistry & Molecular Biology, Monash University, 871 Dandenong Rd, Malvern East 3145, VIC, Australia 4School of Chemistry, Street No., Monash University, 871 Dandenong Rd, Malvern East 3145, VIC, Australia

Self-assembling N-acetyl β3-peptides Ac-β3[LIA], Ac-β3[ALI] and Ac-β3[IAL] have been studied with synchrotron far-IR spectroscopy. These peptides are designed to self-assemble through a 3-point H-bonding motif into a stacked cylindrical geometry that is close to the native 14-helical folding of β3 peptides. The fibrous superstructure has been confirmed by atomic force microscopy imaging.

FIR measurements performed at room temperature showed that the three isomeric peptides exhibit a high degree of similarity in the amide modes between 400-650 cm-1., as expected for a system of highly conserved symmetry. The strong carboxyl mode at ~600 wavenumbers suggests that the C-terminus is not involved in H-bonding in the assembly, thus it can be solvated in the dispersant, consistent with the relative ease of suspending the fibres in protic solvents. While the results indicate that the three sequences are structurally similar, we found that the amide peak at ~450 cm-1 was shifted in case of Ac-β3[ALI] compared to the other isomers indicating that backbone of that peptide adopt a slightly distorted conformation. The experimental results have been correlated to DFT vibrational analysis and structural optimization that was performed using GaussView 5.0 with B3LYP basis set. The optimization was performed without any constrains. Our results reveal a system of highly preserved symmetry with clearly identifiable vibrations in the terahertz range. Acknowledgement The authors acknowledge Dr Joonsup Lee (University of Sydney) for helping with far-infrared spectroscopic data collection and Dr Dominique Appadoo at the Australian Synchrotron for his invaluable insight and technical assistance

Fig. 1. Far-infrared spectra (absorbance) of Ac-β3[LIA], Ac-β3[IAL] and Ac-β3[ALI].

ACOVS11/ASC5 Book of Abstracts Session XXI – Archeaology I

184

SESSION XXI – ARCHEAOLOGY I


185

The Identification of Coatings and Adhesives on Museum Victoria’s Palaeontology Collection using ATR - FTIR R. A. GOODALL1* AND D. MEASDAY1 1Museum Victoria, 11 Nicholson St. Carlton, 3052, Victoria, Australia; [email protected]

Museum Victoria is engaged in an institution wide survey of hazardous substances present in its collection, with an aim to inform the safe handling, storage and display of these materials. This survey has included the identification and analysis of plastic materials in the collection, with a particular focus on ‘malignant plastics;’ chemically unstable plastics which produce substances during their decomposition which are hazardous to museum staff, destructive to the object itself, and also destructive to those objects stored or displayed in proximity to them.1 For example, degrading Cellulose Nitrate (CN) will react with moisture in the air to form corrosive nitric acid. Malignant plastics are found in the collection as 2D films, 3D objects and, because they were the basis of some commonly used adhesives, as coatings, consolidants or repair material applied to collection objects.

Due to the nature of the material collected, the preparation of museum palaeontology collections has always involved the treatment of broken, crushed or fragile specimens, and as such has a long history of organic, semi- synthetic and synthetic polymers used for reconstruction and consolidation of specimens.2 Museum Victoria’s Palaeontology collection has been developed over the last 160 years, and over this time the polymers and practices used by fossil preparators have been continually evolving with the development of field and lab techniques, and new materials provided by polymer science. The preparation methods and materials used in the past were not consistently recorded. The legacy of some of the more unstable polymer materials used in the past is observable in the collection as failed adhesive joins, coatings which darken, crosslink and shrink, surface spalling, peeling and cracking, and lifting of delicate fossils away from the substrate rock. Some coatings cannot be easily removed, and can obscure fine morphological details which may limit the scientific potential of the specimens.

This study used a transportable FTIR with diamond ATR sampling attachment to survey and identify small (<1 mg) samples of adhesives and coatings. This allowed a time line to be established showing trends in polymers use. The earliest specimens particularly, pre 1900, tended to be coated with Shellac, or other natural resins such as Mastic. Early synthetic polymers such as Cellulose Nitrate, a malignant plastic, were found on a small number of specimens, and specimens collected towards the latter half of the twentieth century demonstrated a range of synthetic adhesives and coatings including Polyethylene glycol (PEG), iso-butyl methacrylate (iBMA), Polyvinyl butyral, Polyvinyl acetate (PVAC), Epoxy resins and Cyanoacrylates (Superglue).

The FTIR analysis was also successful in the identification of multiple coatings applied over the same specimen, which produced a history of the past treatment of the fossils. For instance, the analysis of discoloured and peeling coatings on a set of plant fossils revealed the coating consisted of two layers; the first was a protein based glue, which was causing the coating to peel and damage the fossil as it shrunk with age. The second coating was an iso-butyl methacrylate. The iBMA may have been applied as an attempt to stabilise the protein coating, (Fig. 1).

The ability to identify unstable and malignant materials used in the past, is a key tool for informing the long term management and preservation of the collections, the management of hazardous materials in the collection, and provides insights into the timeline of when these materials were used. Acknowledgements We gratefully acknowledge the assistance and advice of David Pickering, Lisa Nink and Dr. Rolf Schmidt. References [1] Y. Shashoua, The Conservation of Plastics: Materials Science, Degradation and Preservation, Butterworth Heinemann, Oxford, (2008) 177. [2] S.Y. Shelton, & D. S. Chaney, In Vertebrate Paleontological Techniques Vol 1; P. Leiggi, P. May (Eds.), Cambridge University

Press: Cambridge (1994), 35–45.

Fig. 1. Two coatings found on one specimen. The protein glue (top) caused the coating to peel. Iso-butyl methacrylate (bottom) was used to consolidate the protein glue.

P 235467 peeling coating on fossil 1_20150306.0 ATR

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186

Surface-Enhanced Raman Spectroscopy for detection of wood residues on stone artefacts by silver nanolayer covering: preliminary results on experimental grinding and scraping tools L. BORDES

Centre for Archaeological Science (CAS), University of Wollongong, Wollongong, NSW 2522, Australia; [email protected]

Detection by Raman spectroscopy of wood residues is a potentially important method to obtain information about the function of prehistoric tools. Wood and bamboo were commonly used in recent times for many purposes (e.g. containers, construction, spears,boomerangs, throwing sticks & digging sticks etc.) and both materials have probably been used since early human occupation of South East Asia, Oceania and elsewhere. Indeed, it is possible to produce a great diversity of wooden artefacts with only rudimentary stone tools, but microwear alone is sometimes not sufficiently developed or preserved to determine their specific function.

Using 532 nm green visible laser excitation, fluorescence and low scattering cross sections are often the main obstacles to obtain clear Raman signals on organic residues, especially those attached on mineral surfaces. To overcome this, Surface Enhanced Raman Spectroscopy (SERS) could be an option to consider because silver/gold nanoparticles or surfaces quench almost all the fluorescence of adsorbed molecules and, at the same time, can enhance specific vibrational modes by a resonance effect.

In addition to the two main methods of applying SERS on molecules (namely nanoparticle colloidal aggregation and deposition of a sample on an active SERS substrate), a silver nanolayer can be coated directly over the residue. This latter method is seldom used, but has the advantage for archaeology of avoiding sample extraction and is non-destructive.

In this preliminary work, two experiments were undertaken. First, wood particles produced by wood scraping tools were placed on a glass microscope slide, and coated by a nanometric layer of silver deposited by a low-pressure vapour method. The Raman signal obtained shows mainly the non-specific disordered carbon G and D band centred respectively on 1580 and 1380 cm-1, but also some more specific vibrational bands in the 600-1200 cm-1 region. Second, nano scale silver layers were deposited on a small sandstone fragment used for wood grinding. Comparable Raman vibrational SERS spectra had been obtained by 532 nm laser excitation on these zones, showing a 870 cm-1 aromatic vibrational band that could be related to the presence of lignin. Further investigations on other mineral surfaces and residues are planned to evaluate the usefulness of this method on archaeological artefacts. References [1] V. W Alyson, P. V Richard, C Francesca, J. Raman. Spectrosc. 37 (2006), 993–1002. [2] M. B Tzolov, N. V Tzenov, D. I Dimova-‐Malinovska, D. Y Yankov, Applied Physics Letters 62 (1993), 2396. [3] U.P Agarwal, R.S Reiner, J. Raman. Spectrosc. 40 (2009), 1527–1534.


187

Binders Used in Metallic Paints Investigated by Micro-FTIR and Synchrotron-sourced FTIR P. DREDGE1*, L. PUSKAR2, L. ALLEN3, M. SAWICKI1 AND R. WUHRER4

1Art Gallery of New South Wales, Art Gallery Road, Sydney, 2000, New South Wales, Australia. [email protected] 2Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Methoden der Materialentwicklung, Albert-Einstein Strasse 15, Berlin, 12489, Germany 3Coburn Fine Art Conservation Pty Ltd, Building 18, 1100a Middle Head Road, Mosman, 2088, New South Wales, Australia 4 Advanced Materials Characterization Facility, University of Western Sydney, James Ruse Drive, Parramatta, New South Wales, Australia

A number of paintings in the collection of the Art Gallery of New South Wales dating from the late 19th to the first half of the 20th century including a small painting by Charles Conder (Fig 1), have been identified as incorporating brass, copper or aluminium metallic paints. The primary use for metallic paint in the nineteenth century was for decoration, craft, sign writing and coach painting. Metallic paints were commonly supplied as separate liquids and powders to be mixed just before use. By the 1930s a number of ready-mixed metallic paints had become available and were popular as paints for leather goods and home appliances. As metallic paints were not manufactured as artists' colours, their presence on paintings provides some of the earliest examples of materials adapted from other uses. The binders used in metallic paints had different requirements to the standard drying oils used in artists’ paints of the period. Metallic paint binders needed to be fast drying and ideally to promote alignment (leafing) of the metallic flakes, while providing a stable non-corrosive environment for the metal. The binders used in these paints are not typical for paintings of the period and may have implications for solvent sensitivity and ageing vulnerability.

Several historic cans of metallic paints available in the 1930s and an artist's paint box containing different types of metallic paint kits (Fig. 2), were examined for this study. The liquid binders, which were either separate or easily decanted, were examined with transmission micro-FTIR. Tung oil, coumarone resin, calcium resinate (gloss oil) and nitrocellulose were identified as some of the binder types. Cross-sections of samples from paintings were prepared and examined with Scanning Electron Microscopy with Energy Dispersive Spectroscopy to identify the metal types. Analysis of the binders in dry metallic paint samples on artworks can be challenging due to the opacity of the metallic flakes preventing conventional transmission and ATR-FTIR analysis. Synchrotron-sourced FTIR of thin-sections cut from the cross-section samples enabled transmission when the metallic flakes were leafed, leaving an area of clear binder below or between flakes. The FTIR mapping also enabled the distinction of several different components within the binder with some phase separation observed.

Acknowledgement This research was initiated and supported by the curators of Australian Art at the Art Gallery of NSW, Deborah Edwards and Denise Mimmocchi during preparation work of the exhibition in 2013, Sydney Moderns Art for a New World. The synchrotron research was undertaken on the infrared beamline at the Australian Synchrotron.

Fig. 2. A collection of metallic paint kits dating from the 1930s. Collection: Artists’ Materials Archive, Art Gallery of New South Wales

Fig. 1. Charles Conder, An Impressionist (Tom Roberts), c.1899, oil and metallic paint on cedar panel, 28.5 x 23.4 cm. Collection: Art Gallery of New South Wales.

ACOVS11/ASC5 Book of Abstracts Session XXII – Ultrafast and Non-Linear Spectroscopy II

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SESSION XXII – ULTRAFAST AND NON-LINEAR SPECTROSCOPY II


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Dynamics of Excited States of Arylaminostilbene Derivatives H.-H. YAO1, H.-H. CHENG1, J.-S. YANG2 AND I.-C. CHEN1* 1Department of Chemistry, National Tsing Hua University, 101 Kuang Fu Road, Section 2, Hsinchu, Taiwan 30013, Republic of China 2Department of Chemistry, National Taiwan Hua University, Taipei 10061, Republic of China

The excited-state dynamics of trans-(N-arylamino)stilbene derivatives with varied substituent 4-hydrogen (p1H), 4-methoxy (p1OM), and 4-cyano (p1CN) in solvents with varied propertied are studied with time-resolved spectroscopy. The structures of these molecules are shown in Fig. 1. Introduction of the N-phenyl substituents leads to a planar ground-state geometry about the nitrogen atom, extended amino conjugation, and a less distorted structure with charge-transfer character for the fluorescent excited state. Accordingly, these molecules have greater cis-trans isomerization barrier and more fluorescence. The trans-(N-arylamino)stilbenes and its derivatives with bipolar donor-acceptor (D-A)-system display varied properties by altering the substituents and the positions. In p1OM twists via the stilbenyl-anilino C-N bond but p1CN via aniline-benzonitrilo C-N bond. In polar solvents, acetonitrile, dimethylformamide, and dimethyl sulfoxide, the transients display decay with three time components (τ1 = 0.7-1.5 ps, τ2 = 4.8-27 ps, and τ3 = 1.2-1.9 ns) for the band centered at 600 nm. In polar solvent an excited-state absorption band near 520 and 480 nm assigned to a singlet twisted intramolecular charge transfer (TICT) band for p1OM and p1CN, respectively but not for p1H. This band has a rise lifetime 4.3, 16.3, and 29.5 ps in ACN, DMF, and DMSO, respectively. This conversion rate displays elongation as solvent viscosity further validating a twisted form in 1TICT state. In nonpolar solvents, we obtained two time components. The first component shows solvent viscosity dependence. We assign it to correspond to conversion from the singlet local excited state 1t* to the perpendicular form 1p* in the stilbene moiety. Then molecule undergoes isomerization to cis stilbene. In alcoholic solvents, the lifetime become significant shorter in p1CN due to H-bond effect but in epoxide solvents the lifetime become extremely long.

Fig. 1. Chemical structures of aminostilbenes.


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Ultrafast Charge Separation Dynamics of Neutral π-Conjugate Systems in Solution Observed by Time-Resolved Near-IR Absorption and Stimulated Raman Spectroscopy T. TAKAYA1*, M. SHINOHARA1, G. MOHRI1 AND K. IWATA1

1Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan; [email protected]

Charge separation in a molecule is one of the elementary processes in chemical reactions. The charge separated species are formed as a result of large rearrangement of electrons in a molecule or molecular complex. According to the quantum well model, molecules have electronic states lying closely to each other when electrons can be delocalised or migrate in the molecule over a large volume. Therefore, the charge separated species often exhibit characteristic absorption bands in the near-IR spectral region. We have recently demonstrated that time-resolved near-IR absorption spectroscopy provides important information on the electronic structure and dynamics of the charge separated species.[1–5] In this study, femtosecond time-resolved near-IR spectroscopy is applied to two kinds of π-conjugate systems in solution. First, we observe the photoinduced intramolecular charge transfer reaction in 9,9’-bianthryl (BA) solubilised in liposome lipid bilayers by femtosecond time-resolved near-IR absorption spectroscopy for estimating the polarity of biomembranes. Second, we investigate the molecular structure of the neutral and charged excitations formed in π-conjugated polymers in solution by femtosecond time-resolved near-IR stimulated Raman spectroscopy.

We have intensively studied the charge transfer dynamics in 9,9’-bianthryl (BA) using femtosecond time-resolved near-IR absorption spectroscopy [1,3–5] as a prototype of the charge separation processes. It has been widely accepted that a locally excited (LE) state of BA is formed by UV irradiation and then converted to a charge transfer (CT) state in polar solvents.[6,7] Time-resolved near-IR absorption and anisotropy spectra of BA strongly indicate that a partial CT state is formed as well as the LE state at the moment of photoexcitation in both nonpolar and polar solvents. The partial CT state is equilibrated with the LE state within 1 ps and then converted to the stable CT state in polar solvents. The time constant of the formation of the CT state depend significantly on the polarity of the solvents, indicating that the solvation process plays a key role in the charge transfer.

BA is expected to be a good probe for estimating the polarity of molecular environments because its charge transfer reaction rate is sensitive to the polarity of solvents in ordinary solution. We used BA for estimating the polarity of biomembranes in order to understand the characteristics of the biomembranes as a “solvent” of biochemical reactions. BA was solubilised in the hydrophobic interior of liposome lipid bilayers formed by dimyristoylphosphatidylcholine (DMPC). Time-resolved near-IR absorption spectra of BA in the DMPC liposome lipid bilayers were recorded from 0 to 1 ns with the photoexcitation at 389 nm. The absorption band of BA in the LE state almost completely decays within 1 ns while a broad and structureless absorption from the CT state appears, which clearly indicates that the charge transfer proceeds in the lipid bilayers of the DMPC liposome. The LE band decays with the three time constants of 0.7 ps, 11 ps, and 70–160 ps. The fastest decay is assignable to the formation of the partial CT state because its time constant is almost identical with those observed in ordinary organic solvents. The other decays are assignable to the full charge transfer processes from the partial CT state. The presence of the two time constants suggests that BA is solubilised in two types of sites of the lipid bilayers with different polarity. Most probably, the faster time constant (11 ps) originates from the charge transfer of BA located in the vicinity of the polar head group while BA that shows the slower time constant (70–160 ps) is located around the centre of the hydrophobic interior in depth. BA in the hydrophobic part will undergo the charge transfer when it migrates to the polar part.

Photophysical properties of π-conjugated polymers, such as high photoconductivity and strong photoluminescence, draw much attention in basic physical chemistry as well as in material science. In solution, structure of the π-conjugated polymers is significantly fluctuated because they have an enormous number of internal degrees of freedom. The structural fluctuation will significantly affect the structure and dynamics of excitations formed in the polymers. We developed a femtosecond time-resolved near-IR stimulated Raman spectrometer [8] and applied it to two fundamental π-conjugated polymers, polythiophene and poly(p-phenylenevinylene), for elucidating the relation between the polymer structure and the dynamics of excitations.

Femtosecond time-resolved near-IR absorption spectra of a polythiophene derivative, P3HT, do not clearly indicate the charge separation in solution, although they show significant downshift of an excited-state absorption band by more than 100 nm in 400 ps. Time-resolved near-IR resonance stimulated Raman spectra of P3HT show a significant downshift of a ring CC stretch band from 1417 to 1366 cm–1 and an increase of intensity for a ring deformation band at 710 cm–1. Similar spectral changes are observed as well for electrochemically oxidised poly(3-decylthiophene) films.[9] The agreement suggests that positively charged excitations are substantially generated in P3HT, although it is believed that the charge separation is negligible in solution.

Time-resolved near-IR absorption spectra of a poly(p-phenylenevinylene) derivative, MEH-PPV, show a downshift of an excited-state absorption band by 80 nm in 60 ps. Time-resolved near-IR stimulated Raman spectra of MEH-PPV, however, show significantly different time dependence from those of P3HT. For MEH-PPV, three stimulated Raman bands are observed at 1550, 1300, and 920 cm–1. Neither of them shows a peak shift or a change in band intensity corresponding to the downshift of the excited-state absorption band. These results do not indicate the formation of the charge separated species in MEH-PPV. The polythiophene chains have much larger probability of the charge separation than the poly(p-phenylenevinylene) chains.


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References [1] T. Takaya, H. Hamaguchi, H. Kuroda, K. Iwata, Chem. Phys. Lett. 399 (2004), 210–214. [2] K. Iwata, T. Takaya, H. Hamaguchi, A. Yamakata, T. Ishibashi, H. Onishi, H. Kuroda, J. Phys. Chem. B 108 (2004), 20233–

20239. [3] T. Takaya, S. Saha, H. Hamaguchi, M. Sarkar, A. Samanta, K. Iwata, J. Phys. Chem. A 110 (2006), 4291–4295. [4] T. Takaya, H. Hamaguchi, K. Iwata, J. Chem. Phys. 130 (2009), 014501. [5] N. Asami, T. Takaya, S. Yabumoto, S. Shigeto, H. Hamaguchi, K. Iwata, J. Phys. Chem. A 114 (2010), 6351–6355. [6] F. Schneider, E. Lippert, Ber. Bunsen-Ges. Phys. Chem. 72 (1968), 1155–1160. [7] F. Schneider, E. Lippert, Ber. Bunsen-Ges. Phys. Chem. 74 (1970), 624–630. [8] T. Takaya, K. Iwata, J. Phys. Chem. A 118 (2014), 4071–4078. [9] G. Louarn, M. Trznadel, J. P. Buisson, J. Laska, A. Pron, M. Lapkowski, S. Lefrant, J. Phys. Chem. 100 (1996), 12532–12539.


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Vibronic Resonances Enable Excited State Coherence in Light Harvesting Proteins at Room Temperature F. NOVELLI1, G. H. RICHARDS1, A. ROOZBEH1*, A. NAZIR2, K. E. WILK3, P. M. G. CURMI3, AND J. A. DAVIS1

1Centre for Quantum and Optical Science, Swinburne University of Technology, Victoria 3122, Australia. 2Photon Science Institute and School of Physics & Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom 2School of Physics, The University of New South Wales, Sydney, New South Wales 2052, Australia.

Following the unexpected observation of persistent quantum coherence in photosynthetic light harvesting complexes [1, 2], the scientific community has undertaken significant theoretical and experimental effort to explain the origin of these effects and what if any role they play in energy transfer. Theoretical studies have suggested that a combination of dephasing caused by Markovian bath of phonons and quantum coherence leads to the most efficient energy transfer [3]. Subsequent studies have proposed theories that overcome the limitations of Markovian and adiabatic approaches [4, 5] and explore the role of coupling between excitonic states and vibrational modes. On the experimental side, several spectroscopy techniques have been developed to elucidate the underlying dynamics and separate the different interactions For instance, narrow bandwidth pulses have been used to selectively excite specific pathways [6] and crossed polarization schemes have been applied to disentangle vibrational and electronic coherences in the non-linear signal [7]. However ambiguities still remain about the nature of the involved states and even whether the observed coherences are in the excited or ground state manifold [8].

In this study we introduce a novel experimental approach based on narrowband two-colour four-wave mixing (FWM) experiment to vary relative weight of quantum pathways in photosynthetic antenna, phycocyanin-645 (PC645). Utilizing this approach we unambiguously identify excited state coherences and detect a low energy vibrational mode (~7meV). This low energy oscillation on the excited state dynamics can only be explained in the picture of vibronic coupling between excitonic and vibrational states.

The narrowband two-colour four-wave technique uses three incident pulses to induce a third-order non-linear polarization in the sample that is detected at the phased-matched direction (ks=-k1+k2+k3) with energy Es=-E1+E2+E3. We set the energy of the pulses E2 = E3 = 2.11 eV (588 nm) and E1 = 2.21 eV (560 nm) so that the first two pulses have different energies and are not spectrally overlapped. By doing this only coherent superpositions can be excited and we are able to subsequently explore the dynamics of these coherent superpositions in isolation from other signal pathways. The evolution of the spectrally-resolved ks is then detected as a function of the waiting time ‘T’, (the delay between the second and third pulses) while the ‘coherence time’, ‘τ’, (delay between the first two pulses) is set to zero.

Under the same excitation condition the fluorescence emission of the sample is also detected at 1.87 eV [9] as a function of intensity of each excitation pulse. Under different excitation conditions a linear rise is fluorescence intensity is followed by saturation. A threshold of 6 nJ per pulse is extracted from a single-exponential fit. By combining observations with different excitation conditions we identify that the observed saturation in the spontaneous emission is due to saturation of the excited states that are directly populated by the laser pulses.

The results from the FWM experiments are shown in Fig.1. The spectrally resolved response of PC645 is illustrated in Fig.1a, as a function of waiting time ‘T’. Here we define coherence energy, Δ, as the gap between states in coherent superposition. The integrated signal at coherence energy 105±10 meV is illustrated in Fig. 1(b-d) to show the evolution of coherence as a function of waiting time and different pulse intensities. The intensity of zero-time response scales with the third power of the laser pulse intensity as one expects for such a third order process (inset of Fig1b). In Fig1c the same results are shown with a rescaled y-axis. At the highest excitation intensity oscillations with a period of 175±25 fs are observed, corresponding to and energy separation of 24±3 meV. This energy spacing is consistent with a vibrational mode also detected in previous studies [6,7]. Similar to zero-time response, the amplitude of this oscillation scales with the third power of the laser pulse as illustrated in the inset of figure 1c. As we decrease the excitation intensity to 11 MW.cm⁻².nm⁻¹, the 24 meV oscillation becomes less obvious and another slower oscillation with a period of 560±60 fs, corresponding to 7meV, becomes more pronounced. The amplitude of this sub-thermal oscillation shows the same saturation behaviour as observed in the fluorescent emission at high excitation densities due to the filling of the excited states. This indicates that the pathways leading to the generation of this component of the signal involve excited state coherent superpositions that evolve during the waiting time. Consequently we can attribute the other signal component, 25±3 meV, to the pathways evolving in ground state vibrational coherences over the waiting time.

We determined the eigenstates of the system taking into account the coupled DBV dimer and the two vibrational modes with energy 24 meV and 105 meV using established parameters. We also calculate vibronic states for this system and the primary composition of each. The vibronic coupling leads to states that are separated by ~7 meV and which are responsible for the oscillations observed in the experiment.

Based on this vibronic model we calculate the dynamics expected for initial conditions matching those excited in the experiments and reproduce the experimental results. Further calculations reveal that not only is a vibronic model able to describe the dynamics, but that it is necessary.

In summary, by exploring the intensity dependence of the third-order system response we have been able to isolate

room temperature coherences that correspond to excited state pathways and which decay on the timescale of the excited


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state lifetimes. The additional identification of 7 ± 1 meV oscillations between quasi-resonant states in the excited state pathways (and not present in the ground state pathways) directly demonstrates the presence of coupling between vibrational modes near-resonant with excitonic gaps and resultant coherence. These data provide a novel perspective for understanding the complex dynamics in the photosynthetic light-harvesting machinery and guidance for future models. Acknowledgement The authors gratefully acknowledge funding from the Australian Research Council, The University of Manchester and Swinburne University References [1] Engel, Gregory S., Tessa R. Calhoun, Elizabeth L. Read, Tae-Kyu Ahn, Tomáš Mančal, Yuan-Chung Cheng, Robert E. Blankenship, and Graham R. Fleming. Nature 446, no. 7137 (2007): 782-786. [2] Lee, Hohjai, Yuan-Chung Cheng, and Graham R. Fleming. Science 316.5830 (2007): 1462-1465. [3] Plenio, Martin B., and Susana F. Huelga. New Journal of Physics 10.11 (2008): 113019. [4] Fassioli, Francesca, Ahsan Nazir, and Alexandra Olaya-Castro. The Journal of Physical Chemistry Letters 1.14 (2010): 2139-

2143 [5] Chin, A. W., J. Prior, R. Rosenbach, F. Caycedo-Soler, S. F. Huelga, and M. B. Plenio. Nature Physics 9, no. 2 (2013): 113-118. [6] Richards, G. H., K. E. Wilk, P. M. G. Curmi, H. M. Quiney, and J. A. Davis. The Journal of Physical Chemistry Letters 3, no. 2

(2012): 272-277. [7] Richards, Gethin H., Krystyna E. Wilk, Paul MG Curmi, and Jeffrey A. Davis. The Journal of Physical Chemistry Letters 5, no. 1

(2013): 43-49. [8] Halpin, Alexei, Philip JM Johnson, Roel Tempelaar, R. Scott Murphy, Jasper Knoester, Thomas LC Jansen, and RJ Dwayne

Miller. Nature chemistry 6, no. 3 (2014): 196-201. [9] Marin, Alessandro, Alexander B. Doust, Gregory D. Scholes, Krystyna E. Wilk, Paul MG Curmi, Ivo HM van Stokkum, and

Rienk van Grondelle. Biophysical journal 101, no. 4 (2011): 1004-1013. [10] Womick, Jordan M., and Andrew M. Moran. The Journal of Physical Chemistry B 113.48 (2009): 15747-15759.

Fig. 1. (a) nonlinear response of PC645 at room temperature. (b-d) The intensity of the observed signal at 95meV is integrated over ±10 meV and plotted as a function of waiting time.


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Time dependent Frequencies of Vibrations from Off-resonant Femtosecond Stimulated Raman Spectra S.-Y. LEE1*, Y. C. WU1 AND B. ZHAO2

1School of Physical & Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, S.637371, Singapore; e-mail: [email protected] 2Department of Chemistry & Chemical Biology, 300 Terrace St. NE, Albuquerque, NM 87131-0001, USA

Femtosecond stimulated Raman spectroscopy (FSRS) on the Stokes side arises from the third order polarization, P(3)(t), which is given by an overlap of a first order wave packet, |Ψ2

(1)(Epu, t)>, prepared by the narrow band (ps) Raman pump pulse, Epu(t), on the upper potential energy surface (PES), with a second order wave packet, < Ψ1

(2)(Epr*, Epu, t)|, that is prepared on the lower PES by the broadband (fs) probe pulse, Epr(t), acting on <Ψ2

(1)(Epu, t)|. [1-2] In off-resonant FSRS, the two wave packets, |Ψ2

(1)(Epu, t)> and <|Ψ1(2)(Epr*, Epu, t)|, resemble each other spatially, as well as to

the zeroth order wave packet |Ψ1(0)(t)> on the lower PES, and the rapid vibrations of the reporter modes on the lower

PES will show up as oscillations in P(3)(t). So, if we can recover P(3)(t) from the FSRS spectrum, we should be able to deduce information on the (quantum-mechanically averaged) time dependent frequencies, ωj(t), of the reporter modes along the trajectory of |Ψ1

(0)(t)>. The observable FSRS Raman gain is related to the imaginary part of P(3)(ω), where P(3)(ω) is the inverse Fourier

transform of P(3)(t). The imaginary part of P(3)(ω), however, is related to the real part of P(3)(ω) by the Kramers-Kronig relation. Hence, from the FSRS Raman gain, we can obtain the complex P(3)(ω), whose Fourier transform then gives us the complex P(3)(t) to analyze for the time dependent frequencies of the reporter modes.

Using a fs actinic pump pulse, Kukura et al. [3] initiated the photochemical cis-trans isomerization of the 11-cis retinal chromophore in rhodopsin. The photoisomerization was then probed by FSRS with a time delay Δt between the fs actinic pump and the fs probe pulse. The FSRS Raman gain spectra of the HOOP region for time delays ranging from 200 – 2000 fs are shown in Fig. 1(a). Using the procedure described above, we can obtain the complex third-order polarization P(3)(t), where the Re{ P(3)(t)} is shown in Fig. 1(b). P(3)(t) can be analyzed for the time-dependent frequencies of the HOOP modes.

The conventional approach [3-5] is to use a functional form for the time dependent frequencies of the vibrations, ωj(t), which are then used in a formula for P(3)(t) whose inverse Fourier transform gives P(3)(ω) and this leads to the FSRS spectrum. Both ωj(t) and P(3)(t) have parameters which are adjustable to provide a good fit of the FSRS spectrum. Alternatively, one can also adjust the parameters to give a good fit of the P(3)(t) that has been derived from the Raman gain spectrum, such as those of Fig. 1(b).

When there is only one reporter mode it can be shown [5] that P(3)(t)/A(t), where A(t) is the envelope of P(3)(t), has a simple exponential oscillatory form, where the derivative of the phase of the oscillations directly gives a time-dependent frequency ω(t). It can be shown that ω(t) is a quantum-mechanical average of the reporter mode frequency ω(Q), which is a function of the isomerization coordinate Q, over the evolving wave packet |Ψ1

(0)(t)> . When there are several reporter modes, as in the case of rhodopsin above, then the Wigner transform of P(3)(t)/A(t) to a distribution in (ω, t) space is a useful tool to obtain the time dependent frequencies ωj(t). FSRS thus offers high spectral resolution due to the ps long P(3)(t), and the latter contains detailed information about the time dependent vibrational frequencies.

Acknowledgement We thank the Ministry of Education, Singapore, for financial support (Grant No. MOE2011-T2-2-087). References [1] Z. Sun, J. Lu, D. H. Zhang, and S.-Y. Lee, J. Chem. Phys. 128 (2008), Art. 144114. [2] K. Niu, B. Zhao, Z. Sun, and S.-Y. Lee, In Advances in Multi-Photon Processes and Spectroscopy; S.H. Lin, A.A. Villaeys, Y.

Fujimura (Eds.), World Scientific: Singapore (2011), Vol. 20, Chapter 1, 1-51. [3] P. Kukura, D.W. McCamant, S. Yoon, D.B. Wandschneider, and R.A. Mathies, Science 310 (2005) 1006-1009. [4] D.W. McCamant, J. Phys. Chem. B 115 (2011) 9299-9305. [5] S. Mukamel and J.D. Biggs, J. Chem. Phys. 134 (2011), Art. 161101.

Fig. 1. (a) Time-resolved FSRS spectra of the HOOP region of photoisomerizing rhodopsin from 200 fs to 2 ps. (b) The real part of the third order time dependent polarization, P(3)(t), is obtained by inversion of the FSRS spectra to the time domain. The time-dependent frequencies of the HOOP modes are contained in P(3)(t).


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Coherent Nonlinear Optical Manipulation of Molecular Vibration and Rotation Y. OHSHIMA

Department of Chemistry, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551, Japan & Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan [email protected]

When a gaseous molecular sample is irradiated by an intense nonresonant ultrashort laser pulse, the laser field exerts a torque that aligns the molecular axis along the laser polarization vector, due to the interaction with the molecular anisotropic polarizability. Here the field–molecule interaction only remains in much shorter duration than the characteristic time for molecular rotation, and thus the rotation of the molecules is coherently excited to create a rotational quantum wave packet (WP). We have developed a method to explore the nonadiabatic excitation in a quantum-state resolved manner and applied it to diatomic and symmetric-top molecules [1]. It has been shown that the state distribution is a useful experimental source for verifying the excitation process [2,3]. When a pair of excitation pulses is implemented with appropriate time delay between them, partial control of rotational-state distribution has been achieved [1,4]. In a favorable case, the double-pulse excitation coupled with the state-selective probe has enabled us to reconstruct experimentally a rotational WP thus created [5]. If the mutual polarization direction and time delay between the two pulses are adjusted, the sense of rotation around the laser propagation direction can also be controlled, yielding to a rotational WP exhibiting angular-momentum orientation [6].

Quite recently, we have succeeded in recording the direct image pertinent to the unidirectionally rotating molecules [7]. Here, the skewed double-pulse pump scheme [6] was adopted to an adiabatically cooled ensemble of diatomic molecules, and the resultant time-dependent spatial distribution pertinent to the molecular-axis direction was probed as an ion image of fragments generated via Coulomb explosion by another femtosecond pulse with circular polarization. Our ion-imaging setup is based on a conventional MCP/phosphor-screen/camera combination, but in contrast to the other ordinary 2D imaging setups, it is able to record images of the fragment-ion clouds sliced perpendicularly to the laser propagation direction. This new configuration enables us to take a “movie” of unidirectionally rotating molecules as a series of records for successive delays between the pump and probe pulses (see, Fig. 1).

Nonadiabatic interaction with a nonresonant intense ultrashort laser field can also coherently excite vibration of molecule through the structural dependence of the molecular polarizability. We also have recently succeeded in creating and observing WPs pertinent to intermolecular vibrations of several molecular clusters in their electronic ground states. The present study is a keystone toward real-time conformational control of flexible molecules.

Acknowledgement Dr. Hirokazu Hasegawa, Dr. Kenta Kitano, and Dr. Kenta Mizuse are greatly appreciated for their magnificent contribution to the works presented herein. Financial supports from MEXT/JSPS Japan, Consortium for Photon Science and Technology, and Riken- IMS Collaboration Program “Extreme Photonics” are acknowledged. References [1] Y. Ohshima, H. Hasegawa, Int. Rev. Chem. Phys. 29, (2010) 619–663. [2] H. Hasegawa, Y. Ohshima, Phys. Rev. A 74 (2006) 061401(R)-1–4. [3] H. Hasegawa, Y. Ohshima, Chem. Phys. Lett. 454 (2008) 148–152. [4] D. Baek, H. Hasegawa, Y. Ohshima, J. Chem. Phys. 134 (2011) 224302-1–10. [5] H. Hasegawa, Y. Ohshima, Phys. Rev. Lett. 101 (2008) 053002-1–4. [6] K. Kitano, H. Hasegawa, Y. Ohshima, Phys. Rev. Lett. 103 (2009) 223003-1–4. [7] K. Mizuse, K. Kitano, H. Hasegawa, Y. Ohshima, Sci. Adv. 1 (2015) e1400185-1–8.

Fig. 1. Selected snapshots of rotational wave-packet dynamics in N2 molecules, (a) induced by a single linearly polarized pulse, (b) by a time-delayed, polarization skewed pulse pair


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Weak Molecular Interaction in Condensed Phases Examined with Time-resolved spectroscopies - Raman and Near-Infrared Absorption K. IWATA

Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan [email protected]

Presence of “weak interactions” in molecular systems affects their properties in a profound way. The weak molecular interactions are weaker than the bonding energies but similar to or stronger than the thermal fluctuation. Partially-ordered structures in the liquid or solution phase, including molecular aggregates, micelles, lipid bilayer membranes, and local structure in ionic liquids, are mainly formed by the weak molecular interactions. They are affected by the thermal fluctuation or by molecular “collisions”. The molecular “collisions” in the liquid or solution phase take place once in every 10-12 to 10-13 seconds. One of the most straightforward methods for studying the molecular systems formed by the weak interactions, therefore, is to use time-resolved spectroscopies that are capable of observing the events with the time resolution of picoseconds to sub-picoseconds. We study the weak molecular interactions mainly with picosecond time-resolved Raman spectroscopy, picosecond time-resolved fluorescence spectroscopy, and femtosecond time-resolved near-infrared absorption/non-linear Raman spectroscopy.

A large number of biochemical reactions proceed at biomembranes with membrane proteins acting as enzymes. The major component the biomembranes is lipid bilayer membranes. The lipid bilayer membranes form a quasi-two-dimensional hydrophobic space, with a thickness of several nanometers, in the midst of water. It is important to examine the nature of this rather strange reaction field for understanding the mechanism of biochemical reactions. We prepare liposomes with a diameter of approximately 100 nm with six different phosphatidylcholines and estimate their basic characters with picosecond time-resolved fluorescence spectroscopy and picosecond time-resolved Raman spectroscopy. We solubilize trans-stilbene in the hydrophobic portion of the lipid bilayer membranes as a probe molecule for both of the measurements. We measure the trans-cis photoisomerization rate constant or the rotational relaxation rate constant, both in the first excited singlet (S1) state, of trans-stilbene with picosecond time-resolved fluorescence spectroscopy. We then estimate the viscosity of the lipid bilayer membranes surrounding the stilbene molecule independently from the two sets of measurement. The results show that there are two solvation environments in the hydrophobic portion of the six lipid bilayer membranes, with viscosity different by 30 to 290 times [1,2]. We also estimate the thermal diffusivity around the stilbene molecule with picosecond time-resolved Raman spectroscopy, by using the stilbene molecule as a molecular thermometer [3]. The result indicates that the lipid bilayer membranes in the liquid crystal phase have larger thermal diffusivity than the membranes in the gel phase. The presence of nearby water that is known to have large thermal diffusivity should affect the heat conduction inside the lipid bilayer membrane. The “picosecond Raman thermometer” has also been successfully applied to explore the local structure formed in room-temperature ionic liquids [4], which are composed of cations often possessing a polar head and a hydrophobic chain and anions [5].

“Loose electrons”, or electrons bound less tightly to the nuclei, play a crucial role in chemical reactions, which are regarded as relocation of valence electrons. The loose electrons including an electronically excited π electron in a C=C conjugated system, an electron in a conduction band, and a solvated electron often show electronic absorption in the near-infrared region. We have developed a femtosecond time-resolved near-infrared absorption/emission spectrometer that covers the spectral region from 900 to 1500 nm for studying the nature of various loose electrons [6]. We have further developed a time-resolved near-infrared non-linear Raman spectrometer, which enables us to record resonance Raman spectra of short-lived species that have electronic absorption in the near-infrared region [7]. By combing the time-resolved absorption/emission spectroscopy and time-resolved non-linear Raman spectroscopy in the near-infrared spectral region, we will be able to understand the mechanism of chemical reactions by clarifying the nature of loose electrons involved in the chemical reactions. References [1] Y. Nojima, K. Iwata, Chem. Asian J. 6 (2011), 1817–1814. [2] Y. Nojima, K. Iwata, J. Phys. Chem. B 116 (2014), 8631–8641. [3] K. Iwata, H. Hamaguchi, J. Phem. Chem. A 101 (1997), 631-637. [4] K. Iwata, H. Okajima, S. Saham H. Hamaguchi, Acc. Chem. Res. 40 (2007), 1174-1181. [5] K. Yoshida, K. Iwata, Y. Nishiyama, Y. Kimura, H. Hamaguchi, J. Chem. Phys. 136 (2012), 104504 1-8. [6] T. Takaya, H. Hamaguchi, K. Iwata, J. Chem. Phys. 130 (2009), 014501 1-9. [7] T. Takaya, K. Iwata, J. Phys. Chem. A 118 (2014), 4071-4078 (2014).


197

Sum-Frequency Generation Spectroscopy of Thiocyanate Oxidation on Polycrystalline Au Surface J. WANG1, M. XU1, Z. HUANGFU1, Y. WANG1, Y. HE1, W. GUO1, Z. WANG1*

1State Key Laboratory of Physical Chemistry of Solid Surfaces, the MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Xiamen University, Xiamen 361005, China and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China. E-mail: [email protected]

As a second order nonlinear technique, sum-frequency generation (SFG) spectroscopy has been used to investigate the molecular adsorption, orientation, packing, and dynamics on in situ electrochemical systems due to its surface selectivity and high sensitivity.

The adsorption and oxidation of thiocyanate ion (SCN-) on polycrystalline Au surface were investigated with broadband sum-frequency generation (BB-SFG) spectroscopy. Potential-dependent behaviours of both the surface adsorbed species and the Au electrode surface had been observed through BB-SFG. In BB-SFG, a picosecond visible light (ωVIS, 2.5 ps, 760 nm, Δν = 7 cm-1) and a femtosecond IR (ωIR, 150 fs, 4750 nm, Δν = 160 cm-1) were used to generate the SFG signal at ωSFG = ωVIS + ωIR. For SFG spectroscopy of electrochemistry systems, the SFG intensity can be written as,

where χ(2) is the second-order surface susceptibility. It comprises two contributions: χ

ads(2) is the resonant part arising from

the adsorbates, and χmet

(2) is the part due to the metallic substrate. Aads is the oscillation strength, and Γ SFG is the half width of the adsorbates vibrations.

Major findings are as follows: (1) Because of the electrochemical Stark effect, the SFG band of the C-N stretching (νC-N) vibration of the SCN-

blue shifted with anodic sweep of the surface potential in the range of -1.1~0.2 V (vs. SCE). The change of the Stark slope indicates that SCN- reorients from N-bound adsorption (-1.2~-0.9 V) to S-bound adsorption (-0.5~0.2 V).

(2) Through the potential-dependent BB-SFG with different pH and concentration of SCN-, the OH- effect on the SCN- adsorption was examined. The Stark slope of νC-N of the S-bound SCN- decreases due to the coadsorption of OH- on Au electrode surface.

(3) The oxidation process of SCN- in different supporting electrolyte (0.1 M NaOH, 0.1 M HClO4, and 0.1 M NaClO4) had been examined. The Au surface oxidized at potentials >0.7 V, and the feature of the BB-SFG spectra changed considerably. New BB-SFG bands around 2228 cm-1 and 2160 cm-1 corresponding to the products of the oxidation (AuCN and Au(CN)2

-) can be observed during anodic sweep. The intensities of these bands varied with surface potential while their peak position kept constant.

(4) The SFG intensity of the Au electrode surface (AAu) varied with surface potential due to the electronic structure changing with adsorption and desorption of surface species, as shown in Fig.1. The AAu changes with desorption and adsorption of surface species until surface oxidation starts in the anodic scan. In cathodic scan, AAu changes significantly with the formation and removal of oxidation layers on the electrode surface.

The adsorption and oxidation behaviours of SCN- observed with BB-SFG match the results from IR and Raman spectroscopy. The response of the Au electrode surface which indicates changes of delicate electronic structure could be clearly seen in BB-SFG as well.

Acknowledgement This work was supported by the National Nature Science Foundation of China (Grant No. 21273179, No. 21327901) References [1] Benedetto Bozzini, Bertrand Busson, Gian Pietro De Gaudenzi, Lucia D’Urzo, Claudio Mele, Abderrahmane Tadjeddine, J.

Electroanal. Chem. 602 (2007): 61–69. [2] Björn Braunschweig, Prabuddha Mukherjee, Robert B. Kutz, Andrzej Wieckowski, and Dana D. Dlott, J. Chem. Phys.

133(2010): 234702. [3] Xiao Li and Andrew A. Gewirth, J. Am. Chem. Soc. 125(2003):11674-11683. [4] Z.Q. Tian, B. Ren, and B.W. Mao, J. Phys. Chem. B 101(1997):1338-1346. [5] A. Tadjeddine, P. Guyot-Sionnest, Electrochimica Acta 36(1991):1849-1854.

Fig. 1. SFG amplitudes of the Au electrode surface with 10 mM NaSCN in 0.1 M HClO4 supporting electrolyte. The circles are for cathodic sweep, and the squares are for anodic sweep, respectively. Lines are guide to the eye.

ACOVS11/ASC5 Book of Abstracts Session XXIII – Archeaology II

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SESSION XXIII – ARCHEAOLOGY II


199

FTIR-ATR identification of cellulose nitrate in museum collections: Middle Eastern archaeological pottery case study E. NOAKE1*, P. NEL2 AND D. LAU3

1Grimwade Centre for Cultural Material Conservation, University of Melbourne – Parkville campus, 3010, Victoria, Australia, [email protected] 2Grimwade Centre for Cultural Material Conservation, University of Melbourne – Parkville campus, 3010, Victoria, Australia, [email protected] 3Manufacturing Flagship, CSIRO, Gate 5, Normanby Rd, Clayton, 3169, Victoria Australia, [email protected]

Cellulose nitrate (CN), the first semi synthetic plastic, was commercially introduced in the 1870s. It came to be widely used in film (photographic and cinematic), and plastic objects. In addition it may also be introduced to an artefact, as an adhesive, consolidant or coating. Thus this material can be found in collections around the world. However, CN is an unstable material, which as it ages, generates damaging by-products1,2, presenting a risk, not only to the material itself, but also to neighbouring artefacts.

Ultimately this research aims to contribute to the development of a model for strategically managing and treating malignant plastics in cultural heritage collections, particularly in the Australian context. Initially this project aims to identify and quantify the prevalence of CN in museum collections. Research conducted at the Grimwade Centre for Cultural Material Conservation (GCCMC) determined approximately two thirds of adhesive repairs in the Cypriot pottery collection housed at the University of Melbourne are composed of CN3,4. To qualify these findings and gain a greater understanding of the characteristics of CN adhesive used in the archaeological context, the survey was extended to incorporate the University’s Middle Eastern archaeological pottery collection. Secondly this research aims to understand and develop the use of analytical tools at cultural heritage institutions for assessing polymeric materials in collections.

To determine the identity of adhesives in the middle eastern pottery collection, micro-samples were removed from artefacts using acetone swabs, and analysed using FTIR-ATR5,6. CN based samples within this data set will later be analysed using GC-MS7 to identify associated plasticizers. To develop tools for aiding Australian cultural heritage institutions with managing polymers in their collections, a survey was undertaken, to determine which institutions have access to FTIR and to gain an understanding of the extent of its use and availability and how it is currently incorporated into management practices. Acknowledgement This research was undertaken as part of a collaborative project between the Grimwade Centre for Cultural Material Conservation, the Centre for Classics & Archaeology, the School of Chemistry, the School of Culture and Communication at the University of Melbourne, Museum Victoria and CSIRO, with support from the McCoy Project Seed Fund. The authors would like to acknowledge the contribution of other members of the McCoy project team: Maryanne McCubbin, Helen Privett, Dr Rosemary Goodall from Museum Victoria; Assoc Prof Alison Inglis, Dr Andrew Jamieson, Dr Alex Duan and Dr Augustine Doronila from the University of Melbourne. References [1] Quye, A & Williamson, R (eds), Plastics: collecting and conserving, NMS Publishing, Edinburgh (1999). [2] Shashoua 2008 Shashoua, Y 2008, Conservation of plastics: Materials Science, Degradation and Preservation, Butterworth-

Heinemann, Oxford. [3] Nel, P; Lonetti, C; Lau, D; Tam, K; Sagona, AG & Sloggett, RJ ‘Analysis of adhesives used on the Melbourne University

Cypriot pottery collection using a portable FTIR-ATR analyzer’ in Vibrational Spectroscopy, vol. 53, (2010), 64–70. [4] Nel, P; Jones-Amin, H; Jamieson, A; Sloggett, RJ & Sagona, AG, New conservation education and research roles for a Cypriot

pottery collection, Museums Australia National Conference, (2010), 129–135. [5] Keneghan, B ‘Assessing plastic collections in museums by FTIR spectroscopy’ in IRUG2 postprints, Victoria & Albert Museum,

London, (1998), 21-24. [6] Derrick, M; Stulik, D & Landry, JM Infrared spectroscopy in conservation science, The Getty Conservation Institute, Los

Angeles (1999). [7] Nel, P; Lau, D & Braybrook, C ‘A closer analysis of old cellulose nitrate repairs obtained from a Cypriot pottery collection’ in

Symposium 2011: Adhesives and Consolidants for Conservation Research: Research and Applications – Symposium papers, 17-21 October 2011, Canadian Conservation Institute, Ottawa, (2012), CD & website, <http://www.cci-icc.gc.ca/symposium/2011/index-eng.aspx>.


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Vibrational Spectroscopy in the Stone Age: identification of residues on stone tools L. C. PRINSLOO1*, R. FULLAGAR1, M. W. MORLEY1, S. LUONG1, L. BORDES1, E. HAYES1, E. FLANNERY, T. SUTIKNA1,2 AND R. ROBERTS1

1Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW 2522, Australia 2 ARKENAS, Jl. Raya Condet Pejaten No. 4, Jakarta 12001, Indonesia [email protected]

Studying stone artefacts from archaeological sites spanning the last few million years is one of the few handles that scientists have to decode how people lived in the distant past. Archaeologists usually classify stone artefacts by their shape, function and particularly by the techniques used to make them, as the nature of the manufacturing technology can be linked to evolutionary phases and cognitive capacity. Analysis of ancient residues preserved on utilised tools and other artefacts can provide very detailed information, such as the specific plant, animal and/or other materials that were actually processed, any decorative applications and what adhesives or particular hafting technologies were adopted. This is not a trivial task as the residues can be thousands of years old and are likely degraded. Furthermore, residues found on stone tools may originate from multiple agencies other than contact material transferred during use. For example, both organic and inorganic residues can be transferred to stone tool surfaces via contact with sediments, groundwater, bacteria, insects and fungi. Therefore residue degradation processes should be studied factoring in the influence of particular depositional environments and archaeological site settings [1].

Artefact residues can only be reliably understood by using multiple lines of evidence and therefore we have embarked on integrating traditional approaches to functional analysis (e.g. study of tool breakage, wear and residue morphology) with the relatively new techniques of vibrational spectroscopy (Raman and infrared) and mass spectrometry coupled to liquid or gas chromatography (GC-MS and LC-MS). Raman and infrared spectroscopy, utilizing a microscope, make it possible to visually link usewear studies to spectroscopic data and as both techniques are essentially non-destructive they are ideally suited for archaeological projects.

It has previously been shown that a combination of infrared spectroscopy and Raman spectroscopy (both red and green excitation) provides the best chance of obtaining comprehensive information because a specific residue composition will respond uniquely to the analytical techniques [2]. Recently, the usefulness of FTIR reflectance spectroscopy has also been successfully demonstrated for studying residues on stone tools—providing a comprehensive database of reflectance spectra is available [3]. Consequently, we have developed a strategy to implement vibrational spectroscopy, first to study a variety of organic and inorganic tissues on different stone types (e.g. quartzite, chert and sandstone) used in controlled tool-use experiments; and second to study the local environment and sediments from each excavation, and finally to analyse and interpret the archaeological artefacts.

A database is being compiled of possible residues (e.g. lipids) commonly identified in traditional usewear/residue studies. The database consists of Raman spectra (red and green excitation) and FTIR spectra (microscope: ATR and reflection and reflection spectra using a portable instrument). The database is also being updated as more information becomes available. The same spectroscopic data are also collected on experimental tools with known residues attached. Where the shape of a residue is important, Raman and FTIR mapping is undertaken, and similar spectra of the tool stone is also recorded. The experimental tools are then buried and recovered for further examination after defined time periods, to understand possible changes taking place through degradation processes. In this we hope to facilitate the interpretation of spectra recorded on the excavated artefacts. As Raman and FTIR spectroscopy is non-destructive this will be a first screening process to determine which artefacts to select for residue extractions and more intense chemical analyses (GC-MS and LC-MS). The portable FTIR instrument will also be utilised on site to help in the selection of artefacts for further analyses.

We present our first Raman and FTIR results for cross sections of sediment layers, selected organic and inorganic substances, experimental tools and artefacts from Liang Bua, the western Flores cave site. Acknowledgement This research is funded by the Australian Research Council FL130100116, awarded to R.G. Roberts. References [1] R. Roberts, R. Fullagar, L. Prinsloo (2015) Australian Science Magazine 36(1): 24–7. [2] L.C Prinsloo, A. Tournié, Ph. Colomban, C. Paris, S. T. Bassett (2013) J. Archaeol. Sc. 40: 1981–1990. [3] L.C Prinsloo, L. Wadley, M. Lombard (2014) J. Archaeol. Sc. 41: 732–739.


201

Analysis of Polymer Art Works for Restoration and Optimise Storage Conditions E. BLAKE1, T. D. MURPHY2*, P. DREDGE3, D. HINTON3, C. LENNARD1, V. SPIKMANS1, AND R. WUHRER2 1School of Science and Health, University of Western Sydney., Penrith, 2751,NSW, Australia 2Advanced Materials Charaterisation Facility, University of Western Sydney, Penrith, 2751, NSW, Australia; [email protected] 3Art Gallery of New South Wales, Art Gallery Road, Sydney, 2000, New South Wales, Australia.

As artists experiment with the use of various mediums it is of upmost importance to understand the chemical composition. This information aids conservators and collection managers in deciding on appropriate preservation strategies, as applied to restorations, storage conditions and display parameters. Often the information provided to a gallery about the medium is a generic ‘plastic’ with no information about the specific plastics or fillers used [1].This work focused on four works currently being curated by The Art Gallery of NSW which are made up of poorly characterised polymers. These works include Plastic Landscape by Tony Coleing (1970), Snake Oil by Hany Armanious (1994), Double Body by Julie Rrap (2007) and The Comforter by Patricia Piccinini (2010) (Fig 1). Analysis of the artworks was carried out using the following techniques:

• Fourier Transform Infrared (FTIR) with Attenuated Total Reflectance (Bruker Vertex 70). This technique is non-destructive and produces rapid results with little sample preparation.

• Raman (Bruker Sentera Laser Raman), utilising 532 nm, 644nm, and 762nm lasers. This technique provided complimentary information to FTIR.

• Scanning Electron Microscopy (SEM) with combined Energy-dispersive X-ray spectroscopy (EDS). (JEOL 6510LV fitted with an AmpTek silicon drift detector using Moran Scientific acquisition software). This technique determined the elemental composition of the sample and was used to show changes to the polymers due to surface degradation.

The combination of these techniques allows for the chemical composition of the polymers in the artwork to be determined and also allowed for the degradation of the artworks to be studied. Preliminary results gained from the analysis of Double Body by Julie Rrap indicate that the sculpture was produced using Trans-230S, a hydrocarbon based silicon defoamer produced by Trans-Chemco Inc. However, further analysis is required to confirm this. Results gained by analysing Plastic Landscape by Tony Coleing indicated that the sculpture was made using a poly vinyl chloride (PVC) plastic.

The information gained by analysing the chemical composition of the art works will be used to determine the best environmental conditions for each piece to be stored in [2]. By understanding the composition the Art Gallery of NSW is able to optimising the storage, restoration and display conditions, and the life of a plastic artwork can potentially be significantly extended. Acknowledgement The authors wish to thank the support from the Art Gallery of NSW and the Advanced Materials Characterisation Facility (AMCF) at the University of Western Sydney. References [1] M. Strlič, K. Curran. Special issue “Polymers in Art and History” – Editorial. Polymer Degradation and Stability. 107 (2014)

189-190. [2] G. Pastorelli, C.Cucci, O. Garcia, G. Piantanida, A. Elnaggar, M. Cassar, M. Strlič. Environmentally induced colour change

during natural degradation of selected polymers. Polymer Degradation and Stability. 107 ( 2014) 198-209.

Fig.1. The Comforter by Patricia Piccinini (2010)


202

Identification of the Coating on the Marble Buddhist Inscriptions of the Kuthodaw Pagoda Complex, Myanmar (UNESCO Memory of the World Register) W.J. READE1*, E. A. CARTER2 AND M. ALLON3

1School of Philosophical and Historical Inquiry, University of Sydney, NSW 2006, Australia [email protected] 2Vibrational Spectroscopy Core Facility, University of Sydney, NSW 2006, Australia 3School of Languages and Cultures, University of Sydney, NSW 2006, Australia

Between 1860-1868 the Burmese King Mindon had the Pali Buddhist canon carved on 729 marble stelae at the Kuthodaw Pagoda in Mandalay. In doing this he fulfilled one of the religious duties of Myanmar kings to preserve the Buddha’s teachings, in all likelihood also prompted by the annexation of lower Myanmar by the British in 1852. Dating as it does to the late nineteenth century, the Kuthodaw Pagoda recension constitutes a unique textual witness not influenced by Western textual practices. Despite their importance (UNESCO “Memory of the World” status 2013), there has to date been no comprehensive study of this site or its texts, nor were the inscriptions being conserved. In 2014 a research team from the University of Sydney and Nan Tien Institute, Australia, began a project to conserve, photograph and study the Kuthodaw Pagoda inscriptions with initial funding from the Chuo Academic Research Institute of Rissho Kosei-kai, Japan (2014–2016).

In this paper we will present a brief account of the nature and historical importance of the Kuthodaw Pagoda site and its inscriptions, known as the ‘World’s Biggest Book’, and will outline the conservation programme we are employing prior to photographing the stelae. During conservation assessment in November 2014, it was noted that the inscribed surfaces of the stelae have at some time in the past been given a protective coating. As previous preservation efforts have not been documented, the coating material was unknown. We have analysed samples of this coating material with the aim of identifying it using IR and Raman spectroscopy at the Vibrational Spectroscopy Core Facility at the University of Sydney.

During the current conservation programme of removal of graffiti and whitewash from the stone stelae, the coating is unavoidably removed to some extent. It is desirable to recoat the stones to protect them in the future from damage, including the acid attack of bat urine to which some stelae have been unfortunately subject.

A suitable modern coating that adheres to conservation standards of stability, longevity, reversibility and suitability for use on stone in the hot climate of Mandalay is expensive and not locally available. We are considering whether it would be preferable instead to source and use the existing type of coating for reasons of affordability and local availability, as well as following what might be revealed to be a more traditional coating method. It is still a common practice today for donors to pay for maintenance of the site, the individual pagodas and of the stelae themselves. This pious work might include re-inking passages of text or coating the stelae. Unfortunately, it has not been possible to access local knowledge about the materials used when these projects are undertaken. The identification of the coating material is important for its potential to help us to assess its suitability from both conservation and traditional cultural perspectives.

Acknowledgements The authors would like to acknowledge generous funding from the Chuo Academic Research Institute of Rissho Kosei-kai, Japan, and the ongoing support of the Myanmar Ministry of Culture, the Mandalay Department of Archaeology and the Custodians of the Kuthodaw Pagoda site.

ACOVS11/ASC5 Book of Abstracts Session XXIV – Mapping and Imaging

203

SESSION XXIV – MAPPING AND IMAGING


204

Mapping Signals of Early Life Stress Events in Teeth Using Raman Spectroscopy C. AUSTIN1, 2*, T. M SMITH3, E. A. CARTER4, 5, J. LEE4, 5, P. A. LAY4, 5, B. J KENNEDY5 AND M. ARORA1, 2

1Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA [email protected] 2 Faculty of Dentistry, The University of Sydney, Sydney, New South Wales 2006, Australia 3Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA 4Vibrational Spectroscopy Core Facility, The University of Sydney, Sydney, New South Wales 2006, Australia 5School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia.

Early life stress can disrupt or alter development and negatively impact long-term health trajectories [1]. The timing of stress events is important as it can determine which organs or systems are affected and to what degree [2]. Therefore, studies of the health effects of stress need to consider the timing and intensity of stress events. However, an absence of retrospective time-specific biomarkers has hampered the study of critical development windows of heightened susceptibility to stress.

Defects in tooth enamel have been used to reconstruct stress history [3]. Teeth grow in an incremental pattern, similar to trees, with daily growth rings that can be counted in dentine and enamel. A prominent growth ring formed at birth, the neonatal line, is used to age growth rings before and after birth. Stress can disrupt enamel and dentine deposition resulting in accentuated growth rings. However, current methods (light microscopy) used to identify accentuated growth rings are subjective and highly dependent on operator expertise, quality of sample preparation and microscopy technique [4].

Here we demonstrate the novel application of high-resolution Raman spectroscopic mapping to identify accentuated growth rings in teeth from captive macaques with detailed medical histories. Discrete banding was observed as minor changes in the biomineral structure (e.g. carbonate substitution), organic biomolecular content and protein conformations of dentine relative to adjacent healthy dentine. These differences were confirmed with principle component analysis. The discrete banding pattern corresponded to events recorded in the animal’s medical histories and accentuated growth rings observed with light microscopy. Raman mapping revealed fine-scale features in dentine that were not visible using light microscopy (Fig. 1). These features may represent a combination of regular, rhythmic incremental growth rings as well as aperiodic accentuated growth rings.

The method requires limited sample preparation, provides fine temporal detail and is effective in analysing both enamel and dentine. Most importantly, Raman mapping offers the potential of an objective and quantifiable reconstruction of stress history. Using this method, teeth can provide a more comprehensive description of early life in epidemiological and public health studies, ultimately leading to a better understanding of the role of early life stress in long term health trajectories. References [1] S. B. Johnson, A. W. Riley, D. A. Granger, J. Riis, Pediatrics. 131 (2013), 319-327 [2] S. J. Lupien, B. S. McEwen, M. R. Gunnar, C. Heim, Nat. Rev. Neurosci. 10 (2009), 434-445 [3] T. M. Smith, Ann. Rev. Anthropol. 42 (2013), 191-208 [4] T. M. Smith, D. J. Reid, J. E. Sirianni, J. Anat. 208 (2006), 125-138

Fig. 1. Raman map of the area under the 853 cm-1 band collected from a macaque molar. (785 nm, 15 mW, x100/0.75 NA objective, 1.4 µm step size, 2.3 s and YBin= 2). Green arrows indicate regular incremental markings and blue arrows accentuated growth rings.


205

Clues to UHPM — using Raman spectroscopy and mineral equilibria modelling to examine pressure variation in UHP garnet from Dabie Shan and Tso Morari eclogites A. RAJKUMAR1*, G. L. CLARE1, J. C. AITCHISON1 AND E. A. CARTER2

1School of Geosciences F09, University of Sydney, Sydney, NSW 2006 Australia email: [email protected] 2Vibrational Spectroscopy Core Facility, Madsen Building F09, University of Sydney, Sydney, NSW 2006 Australia.

Minerals inclusions and their host can undergo and record evidence of ultra-high pressure metamorphism (UHPM); e.g. coesite and diamond. Differences in expansivity and compressibility properties of mineral inclusions phases to mineral host phases can lead to the development of residual or non-lithostatic pressures. Garnet porphyroblasts and their inclusions from well-known and documented UHP terranes; Dabie Shan in central China and Tso Morari in Ladakh, north-western India (around ~ 30 kbar and 620 ± 30 °C and 29–30 kbar and 610 ± 20 °C, respectively) are analysed using Raman spectroscopic 3D volume mapping to investigate the residual pressure relationship between inclusion and host pairs. Taking into account the pressure- and temperature dependency of compressibility and expansivity of garnet and quartz inclusions, a simple elastic model is used together with shifts in measured Raman frequencies to determine the metamorphic conditions prevalent at the time the inclusion was captured by the host garnet. Analysis of host-inclusion systems from the eclogite samples suggests a residual pressure of < 8 kbar can still be produced in quartz inclusions that have not yet undergone volumetric changes to coesite within garnet in UHP metamorphic rocks. These results suggest that grain scale pressure variation should be an important consideration in the application of equilibration thermodynamics in calculation PT conditions of UHPM terranes. Acknowledgement We acknowledge all contributors who read this brief guide to the end. References [1] P. Carmona, M. Molina, R. J. Escobar, J. Raman. Spectrosc. 22 (1991), 559–566. [2] J. C. Austin, T. Jordan, T. G. Spiro, In Biomolecular Spectroscopy; R. Clark, E. R. Hester (Eds.), John Wiley& Sons: Chichester

(1993), 55–123. [3] M. Enami, T. Nishiyama, T. Mouri, Mineralogical Journal. 13 (2007), 151–160.

ACOVS11/ASC5 Book of Abstracts Session XXV – Synchrotron III

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SESSION XXV – SYNCHROTRON III


207

Heavy snow: IR spectroscopy of isotopically diluted water ice particles E. G. ROBERTSON1*, A. WONG2, C. MEDCRAFT2, M. RUZI1, D. MCNAUGHTON2 AND D. APPADOO3

1Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, Victoria, Australia 2School of Chemistry, Monash University, Wellington Road, Clayton, Victoria, 3800, Australia. 3Australian Synchrotron, Blackburn Rd., Clayton, 3168, Victoria, Australia

Aerosols impact earth’s climate both directly through absorption and reflection of light, and indirectly by hosting chemical reactions and influencing cloud formation. They play an important role in interstellar chemistry, particularly those involving molecular ices. And water itself is strange stuff –its apparently simple molecular structure that gives rise to many unique properties in condensed phases. Intense scrutiny by spectroscopy and theory has not yet resolved all the questions, and the vibrational spectroscopy of water ice is no exception. Studies over the past eight decades have revealed IR and Raman spectra of great complexity, and this is only enhanced when the water is present in particle form.

Recently, a new generation of collisional cooling cell designed by one of our collaborators [Bauerecker 2001] has created new possibilities for systematically studying aerosols generated by pulsed sequences of injections. We have used one of these cells, coupled to the Bruker IFS125HR spectrometer on the High Resolution Infrared Beamline at the Australian Synchrotron, for both high resolution gas phase studies and for aerosol studies. Development work on the cooling cell has made it possible for the first time to extend these types of aerosol measurements to the crucial but hitherto unexplored far IR region. IR Spectra have been measured for aerosols comprised of small organic and inorganic molecules, and aerosols of water ice provide a case study of how much may be learned from such spectra.

Crystalline water ice particles in the nanoscale size regime were generated by rapid collisional cooling at temperatures ranging from 4-209 K. Their spectra have been measured in the far-IR region for the first time, using synchrotron radiation and we have systematically explored size and temperature effects in the mid IR region. Spectral features associated with the particle’s more amorphous surface are diagnostic for size. The particle size regime studied (3-150 nm) is such that scattering effects are negligible, and the onset of less crystalline behaviour may be observed for particles smaller than around 5nm. Notably, the aerosol spectra show significant differences compared to previous thin film spectra. These measurements provide a means to assess optical constants required for radiative forcing calculations in many contexts, including earth’s energy balance. In further experiments, introduction of D2O sample allowed production of deuterium enriched crystalline ice, or “heavy snow” containing H2O, HOD and D2O in various proportions. The spectral features associated with libration, bend and stretch modes in these isotopologues are analysed as a function of temperature. Dilution, and hence decoupling, of the vibrational OH oscillators leads to considerable simplification in the OH stretch spectral region, and correspondingly in the OD stretch for diluted OD oscillators. When compared to sophisticated MD simulations from the group of Skinner, the results provide insights into the fundamental nature of the ice spectral bands. Acknowledgement This work was generously supported by the Australian Synchrotron through beamtime allocations and non-beamtime facility access. We also gratefully acknowledge the support of beamline staff. References [1] S. Bauerecker, M. Taraschewski, C. Weitkamp and H.K. Cammenga, Rev. Sci. Instr., 72 (2001), 3946. [2] C. Medcraft, D. McNaughton, C.D. Thompson, D.R.T. Appadoo, S. Bauerecker, E.G. Robertson, Astrophys. J. 758, 17 (2012). [3]. C. Medcraft, D. McNaughton, C.D. Thompson, D.R.T. Appadoo, S. Bauerecker, E.G. Robertson, Phys. Chem. Chem. Phys., 15, 3630-3639 (2013).


208

THz coherent Synchrotron Radiation used for Ultra High resolution Spectroscopy and Ultra-fast THz measurements J. TAMMARO1, O. PIRALI1,2, G. MOURET3, F. HINDLE3, A. CUISSET3, J-F. LAMPIN4, G. DUCOURNAU4, E. ROUSSEL5, C. SZWAJ5, C. EVAIN2, S. BIELAWSKI5, L. MANCERON1, J. B. BRUBACH1, M. A. TORDEUX1, M. E. COUPRIE1, AND P. ROY1* 1Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France 2Institut des Sciences Moléculaires d’Orsay, UMR8214 CNRS – U. Paris-Sud, 91405 Orsay, France 3LPCA, Université du Littoral côte d’opale, 59140 Dunkerque, France 4IEMN, Avenue Poincaré-Cité Scientifique, 59652 Villeneuve D’Ascq 5Laboratoire PhLAM, UMR CNRS 8523, Université Lille 1, 59655 Villeneuve d'Ascq, France

During the last decade, an unprecedented high power source of THz radiation was made scientifically available:

coherent synchrotron radiation (CSR) [1-3]. This radiation produced from relativistic electron bunches of picosecond duration opens up new territory in the THz range with intensities up to 4 orders of magnitude higher than previous sources. In this mode of operation [4,5], we observed the bunch shape with micron resolution using the Electro Optics sampling technique and verified how its shape is at the origin of the intense emission. This technique revealed that the stability is sufficient to perform bunch per bunch measurements allowing kinetics study at the nsec resolution.

Other extreme properties have been recently unveiled: the CSR emission forms two frequency combs (FC) generated over one decade of frequency. The first one originating from the electron bunch to bunch repetition is the signature of a degree of coherence amongst bunches and is designated as super radiance emission [6]. At SOLEIL, recent heterodyne mixing measurements [7] revealed a second FC composed of sharp teeth regularly spaced by 846 kHz and related to the revolution period of the electron bunches in the storage ring (1.18 µs). It produces a spectrally dense THz FC covering the THz range from 0.1 to 1 THz. This FC presents unprecedented properties such as high power, broad frequency range, zero frequency offset, and high density. The CSR discrete emission reveals that for the THz coherent emission, the entire ring behaves in a similar fashion to a resonator wherein electron bunches emit pulses quasi-synchronously.

These properties will allow to exploit the CSR FC for ultra-high resolution spectroscopy. References [1] G. Stupakov and S. Heifets, Phys. Rev. ST Accel. Beams,5, 054402 (2002). [2] J. M. Byrd, W. P. Leemans, A. Loftsdottir, B. Marcelis, M. C. Martin, W. R. McKinney, F. Sannibale, T. Scarvie, and C. Steier, Phys. Rev. Lett., 89, 224801 (2002). [3] M. Abo-Bakr, J. Feikes, K. Holldack, G. Wustefeld, and H.-W. Hubers, Phys. Rev. Lett., 88, 254801 (2002). [4] Roussel, E., Evain, C., Le Parquier, M., Szwaj, C., Bielawski, S., Manceron, L., Brubach, J. B., Tordeux, M. A., Ricaud, J. P., Cassinari, L., Labat, M., Couprie, M. E. and Roy, P. , Scientific Reports, 2015, 5 : art.n° 10330 [5] Barros, J., Evain, C., Roussel, E., Manceron, L., Brubach, J. B., Tordeux, M. A., Couprie, M. E., Bielawski, S., Szwaj, C., Labat, M. and Roy, P. , J. of Mol. Spec., 2015, 315: 3-9 [6] B. E. Billinghurst, J. C. Bergstrom, L. Dallin, M. de Jong, T. E. May, J. M. Vogt, and W. A. Wurtz, PRST - 16, 060702 (2013). [7] Tammaro, S., Pirali, O., Roy, P., Lampin, J. F., Ducournau, G., Cuisset, A., Hindle, F. and Mouret, G. , Nature Communications, 2015, 6

Fig. 1. Spectral distribution of the CSR Intensity measured for various bunch currents showing the appearance of CSR. The total emitted power is 2 mW for 20 mA of total current in the ring..


209

Molecular Beam Microwave Spectroscopy and Slit-jet IR Spectroscopy: From carbon bond to gas phase nucleation S. P. GNANSEKAR1, M. GOBET2, R. GEORGES3 AND E. ARUNAN1* 1Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012 India. Email: [email protected] 2Laboratoire PhLAM, Universit´e de Lille 1, Villeneuve de Ascq, France. 3IPR UMR6251, CNRS - Universit´e Rennes 1,Rennes, France.

Our laboratory uses a pulsed nozzle Fourier transform microwave spectrometer to investigate hydrogen bonded and van der Waals complexes formed in a supersonic beam.1 Results from our recent investigations on Ar-propargyl alcohol complex2 led us to propose a ‘carbon bond’3 analogous to the ‘hydrogen bond’. Theoretical investigations suggested that a complex formed between H2O and CH3F could have two geometries. The ‘hydrogen bonded geometry’ has a structure in which O-H from H2O interacts with F. The other structure has the O from H2O interacting with the C through the CH3 face. The later leads to a pentacoordinate carbon in which F-C---O angle is linear, very much like F-H---O in the hydrogen bonded complex between H2O and H-F. Moreover, the C-F stretching frequency is red-shifted. Microwave experiments in Bangalore and Lille and infrared experiments at the Soleil Synchrotron facility were carried out to study the H2O---CH3F complex. Microwave experiments showed evidence for the hydrogen bonded geometry. Infrared experiments with a slit-jet nozzle showed evidence of water nucleation in the presence of CH3F.4 During this talk, results from both experiments will be described along with those from computational and modeling studies. Acknowledgement We acknowledge the Indo-French Center for Promotion of Advanced Scientific Research for financial support. References [1] E. Arunan, S. Dev and P. K. Mandal, Appl. Spectrosc. Rev.39 (2004) 131. [2] D. Mani and E. Arunan, ChemPhysChem 14 (2013) 754. [3] D. Mani and E. Arunan, Phys. Chem. Chem. Phys. 15 (2013) 14377. [4] Sharon P. Gnanasekar, M. Gobet, E. Arunan, R. Georges, P. Soulard, P. Asselin, T. R. Huet, and O. Pirali, Presented at the

International Symposium on Molecular Spectroscopy, University of Illinois at Urbana-Champaign (2015).


210

Temperature and environmental effects on the IR spectra of ferrocene – The meeting place of experiment and theory F. WANG1*, S. BEST2, C. CHANTLER3, S. ISLAM1, T. ISLAM2, R. TREVORAH3 AND D. APPADOO4 1Molecular Model Discovery Laboratory, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Melbourne, Victoria, 3122, Australia. E-mail [email protected] 2School of Chemistry, University of Melbourne, Parkville, Victoria 3052, Australia, 3School of Physics, University of Melbourne, Parkville, Victoria 3052, Australia, 4Far-IR and High Resolution FTIR Beamline, Australian Synchrotron, 800 Blackburn Road, Clayton, Vic. 3168, Australia

The discovery of the hydrogenases and subsequent understanding of their structure and chemistry represent the major breakthrough towards novel catalysis and solutions for hydrogen production and fuel cells [1]. As a result, understanding the structural and functional details of the active site of hydrogenases through X-ray crystallography, spectroscopic and computational methods, has been the bottleneck of biomimetic and bioinspired catalysts in chemistry. It is important to understand Fc structure but since its discovery, the heated debate whether the eclipsed (e-Fc) or the staggered (s-Fc) sandwich complex is the most stable structure of Fc continues. The fact that electronic structures and many properties of the Fc conformers are strikingly similar has been a key hurdle to differentiate or separate the configurations from one another. We recently revealed theoretically using DFT calculations that the 400-500 cm-1 region of the infrared (IR) spectra of Fc [2] exhibits the fingerprint for Fc conformers, in agreement with an earlier measurement [3].

In order to further understand the details Fc conformers, we conducted a number of interesting quantum mechanical calculations and designed a series of IR measurements in gas, solution and solid phases, with respect to Fc, deuterated Fc-d10 and partially deuterated Fc-d2 (calculation only) under various conditions. To mimic the conditions of the quantum mechanical calculations, the measurements were designed at a number of temperatures including very low temperatures to reduce the population in the excited vibrational states of the complex. While the measurement of low-temperature IR spectra of “isolated molecules” can achieved by the use of noble-gas matrices, a simpler method using paraffin wax has been applied to the preparation of samples of ferrocene (Fc) for cryogenic IR spectroscopy. By control of the solute concentration it has been possible to achieve spectra characteristic of those obtained from RT solutions in non-coordinating solvents where the wax samples have the advantage of being suitable for low temperature measurements, avoiding further crystallisation during cooling.

The key IR bands sensitive to the conformational form of Fc are found to have a complicated temperature dependence that provides information on the conformational distribution of the species and the shape of the potential energy surface. Importantly, the low temperature spectra give a pattern of IR bands in excellent agreement with our DFT calculation (band splitting and intensities). The study has implications both in terms of the conformational analysis of the archetypal organometallic arene, Fc, but also the relationship between the calculated and observed IR spectra of molecules with low energy conformational barriers. Acknowledgement Allocation of beamline time at the Australian Synchrotron and Swinburne University SwinGSTAR supercomputer facilities are acknowledged. SI acknowledges Swinburne University Postgraduate Research Award (SUPRA). References [1] G. Caserta, S. Roy, M. Atta, V. Artero and M. Fontecave, Curr. Opinion in Chem Bio, 25(2015)36-47. [2] Mohammadi, N., A. Ganesan, C. T. Chantler and F. Wang, J. Organomet. Chem., 213(2012)51-59. [3] Lippincott, E.R. and R.D. Nelson, Spectrochim. Acta, 10(1958)307-329.

Fig. A. Measured IR spectra of Fc at various temperatures in dilute wax solutions. Fig. B & C. Calculated IR spectra using B3LYP/m6-31G* model (E-Fc and S-Fc respectively) in vacuum.

ACOVS11/ASC5 Book of Abstracts Session XXVI – Neutron Spectroscopy

211

SESSION XXVI – NEUTRON SPECTROSCOPY


212

Vibrational Neutron Spectroscopy of Organic and Inorganic Molecules A. P. J. STAMPFL

Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, 2234, NSW, Australia [email protected]

A low energy band pass neutron spectrometer that operates in the range of 50-1200 cm-1 has very recently been commissioned and first experiments run at the OPAL reactor. The so-called Be-filter spectrometer is predominantly used to obtain vibrational density of states from those materials with a high incoherent scattering cross section: generally any system containing hydrogen allows molecular vibrations to be acquired at temperatures below about 100 K. Non-hydrogenous material is also sometimes measurable when the total scattering cross section is appreciable or when collective excitations, such as phonon modes, dominate the spectrum. In many aspects such a neutron spectrum is very similar to spectra obtained using an infrared spectrometer, albeit that the neutron spectrum is not governed by selection rules and is very much a bulk measurement due to the neutrons outstanding materials penetrability.

A number of organic and inorganic systems are presented that highlight the capabilities of the technique and a description of the spectrometer is given.


213

On the phase-transition mechanism of CuQ2-TCNQ molecular crystals D. H. YU1*, G. J. KEARLEY1, G. F. LIU2, R. A. MOLE1 AND X. T. TAO2

1Bragg Institute, Australian Nuclear Science and Technology Organization, NSW 2234, Australia, [email protected] 2State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P.R. China,

Recently, a single-crystal-to-single-crystal (SCSC) phase transition with remarkable dimension changes, under mechanical stimulation, has been observed in a classical molecular crystal 7, 7, 8, 8 - tetracyanoquinodimethane-p-bis (8-hydroxyquinolinato) copper(II) (CuQ2-TCNQ, form-II) [1]. At the transition from form-II to form-I the crystal undergoes about 100% increase in length and 50% reduction in thickness. The phase transition mechanism of CuQ2-TCNQ molecular crystals has been studied with combination of neutron spectroscopy, molecular dynamic (MD) simulation and Hirshfeld surface analysis. Inelastic neutron scattering and MD simulations have shown softening of phonon modes related to intralayer H-bonds upon phase transition from From-II to Form-I. The spectral changes are rather small and point to the limited role of H-bond interactions in the phase transition, the main driving force for the phase transition being the re-optimisation of interlayer π-π interactions. This interpretation is supported by an analysis of the Hirshfeld surfaces.

Acknowledgement The authors would like to acknowledge the Bragg Institute at ANSTO for the allocated beam time on Pelican instrument. This work was supported by the National Natural Science Foundation of China (grant no. 51321091). References [1] G. Liu, J. Liu, Y. Liu, X. Tao. J. Am. Chem. Soc., 136 (2014) 590.

Fig. 1. Generalized phonon density of states (GDOS) at 300 K. Symbols and lines represent experimental data and MD simulation, respectively.


214

Deuterium labelling at Australia’s National Deuteration Facility: Characterization of Biopolymer Nanocomposite Systems using Infrared Microspectroscopy. R. RUSSELL1,2*, T. DARWISH1, P. HOLDEN1,2, L. JOHN, R. FOSTER2

1 National Deuteration Facility, Australian Nuclear Science and Technology Organisation, New South Wales, Lucas Heights, Australia [email protected] 2 Bio/Polymer Research Group, School of Biotechnology & Biomolecular Sciences, University of New South Wales, Sydney, Australia

Microbial polyesters such as polyhydroxyalkanoates (PHAs) show great potential as biomaterials and bioplastics. Whilst poly(3-hydroxybutyrate) (PHB) is biocompatible and biodegradable, its relatively high crystallinity limits its applications. By contrast, poly(3-hydroxyoctanoate) (PHO) is highly flexible, and consequently blending of the two has been suggested for fabrication of biomedical devices, e.g. cardiovascular stents. Blending of polymers is commonly used to improve material performance, however the characterization of chemically similar polymers, such as PHB and PHO, can prove difficult.

Australia’s National Deuteration Facility has co-located chemical and biosynthesis laboratories, allowing for the production of the required deuterated fatty acid (d15-octanoic acid) and its subsequent use as substrate for microbial synthesis of deuterated PHO.

A novel combination of polymer biodeuteration and Infrared Microspectroscopy (IRM) was used to map phase behaviour of PHB/PHO blends to study their miscibility. Bio/deuteration overcomes a major limitation in the use of IRM when applied to differentiate between polymers of similar chemical compositions which typically produce overlapping IR peaks.

The differentiation between C-H and C-D bonds of protonated PHB and deuterated PHO, respectively, clearly shows the phase separation throughout the thickness of the film cross section (Fig. 1). Introduction of carbon nanotubes not only alters the interface between the polymer phases, it decreases the resistivity of these insulating polymers. The resulting bio-nanocomposite has potential application as a scaffold particularly suited to nerve regeneration.

Acknowledgement IR analyses were undertaken on the Infrared beamline and associated instruments at the Australian Synchrotron, Victoria, Australia.

Fig. 1. IRM map of Protonated PHB/ Deuterated PHO polymer blend film cross-section.

ACOVS11/ASC5 Book of Abstracts Session XXVII – Plasmonics II

215

SESSION XXVII – PLASMONICS II


216

Aggregation Enhanced Two-Photon Photoluminescence of Metal Nanoparticles Q.-H. XU

Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543; E-mail: [email protected]

Noble metal nanoparticles, such as Ag and Au, have been known to display many unique optical properties such as

surface Plasmon resonance. Plasmon coupling arises when metal nanoparticles come to close proximity, resulting in a red-shifted Plasmon band and significant enhancement of various optical responses such as surface enhanced Raman scattering (SERS), which has been utilized to develop various applications [1].

In addition to SERS, nonlinear optical responses such as two-photon photoluminescence (2PPL) are expected to be significantly enhanced due to their nonlinear dependence on the incident intensity. Our recent studies showed that addition of cationic conjugated polymers into Au and Ag nanoparticle solutions can induce aggregation of metal nanoparticles, which resulted in a SERS enhancement factor ~400 times stronger than isolated gold nanoparticles [2]. 2PPL of Ag nanoparticles were found to be enhanced by ~50 times when Plasmon coupling was induced by addition of conjugated polymers [3]. Such Plasmon coupling enhanced 2PPL was subsequently demonstrated in Au, Ag and Au/Ag alloy nanoparticles of different sizes and shapes [4, 5, 6]. As many chemically and biologically important species can induce aggregation of metal nanoparticles, this aggregation induced 2PPL enhancement phenomenon could be utilized to develop various two-photon applications to take the unique advantages of two-photon excitation such as deep penetration into biological tissues and 3-dimensional confined excitation. We have demonstrated the applications in two-photon sensing of Hg2+, cysteine, glutathione, thrombin, and DNA nuclease [5-7]. We have also demonstrated aggregation enhanced two-photon singlet oxygen generation and applications in two-photon bio-imaging and phototherapy [8]. Single particle spectroscopy has been utilized to study 2PPL properties of various coupled nanostructures such as Au nanosphere dimers and trimers [9], dimers of Au nanorods, nanoccues and nanotriangles as well as various heterodimers. 2PPL properties of these nanostructures were found to strongly depend on the particle morphology and coupling strength between nanoparticles. Ultrafast two-pulse emission modulation experiments have been performed to investigate the underlying enhancement mechanisms to reveal their excitation nature of two sequential one-photon absorption processes, in which the intermediate states act as the bridge states to significantly facilitate the absorption of two photons to promote the system to the emitting state. [9]. Acknowledgement We acknowledge the financial support from the NUS AcRF Tier 1 grant (R-143-000-607-112) and the National Research Foundation, Prime Minister’s Office, Singapore under its Competitive Research Program (CRP Award No. NRF-CRP10-2012-04). References [1] L Polavarapu, J. Pérez-Juste, Q.H. Xu, L.M. Liz-Marzán, J. Mater. Chem. C, 2 (2014), 7460-7476. [2] L. Polavarapu and Q.-H. Xu, Langmuir, 24 (2008), 10608-10611. [3] Z.P. Guan, L. Polavarapu, Q.-H. Xu, Langmuir, 26 (2010), 18020-18023. [4] P. Yuan, R. Ma, N. Gao, M. Garai, Q.H. Xu, Nanoscale 7 (2015), 10233-10239. [5] P.Y. Yuan, R.Z. Ma, Z.P. Guan, N.Y. Gao, and Q.-H. Xu, ACS Appl. Mater. Interf., 2014, 6(15), 13149-13156. [6] C.F. Jiang, Z.P. Guan, S.Y.R. Lim, L. Polavarapu, Q.-H. Xu, Nanoscale, 3 (2011), 3316-3320. [7] C.F. Jiang, T.T. Zhao, S. Li, N.Y. Gao, Q.-H. Xu, ACS Appl. Mater. Interf., 5 (2013), 10853-10857 . [8] P. Yuan, X. Ding, Z. Guan, N. Gao, R. Ma, X.F. Jiang, Y.Y. Yang, Q.H. Xu, Adv. Healthcare Mater. 4 (2015), 674-678. [9] Z.P. Guan, N.Y. Gao, F. Han, Q.-H. Xu, J. Am. Chem. Soc. 135 (2013), 7272-7277. [10] X.-F. Jiang, Y.L. Pan, C.F. Jiang, T.T. Zhao, P.Y. Yuan, T. Venkatesan, and Q.-H. Xu, J. Phys. Chem. Lett. 4 (2013), 1634-1638.

Fig. 1. Optical spectroscopic studies and applications of aggregation enhanced 2PPL of plasmonic metal nanoparticles in sensing, imaging, and therapy.


217

Toward Plasmonic Fano-resonance Enhanced Spectroscopy: From Raman to Infrared Scattering

J. YI1, S.-Y. DING2* AND Z.-Q. TIAN1, 2* 1State Key Laboratory of Physical Chemistry of Solid Surfaces and Dept. of Chem., College of Chem. and Chem Engineering, Xiamen University, Xiamen, 361005, China. 2Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Xiamen University, Xiamen, 361005, China Email: [email protected], [email protected]

By coupling with the enhanced local electromagnetic (EM) fields generated by surface plasmon resonance, the vibrational signals of analytes in the vicinity of the plasmonic micro/nano- confined structure can be amplified by several orders of magnitude [1]. Therefore, SES strongly depends on the development of new concepts and nanostructures in nano-plasmonic. Recently, many researchers have reported that plasmonic nanostructures with Fano resonance arise from interferences between super-radiant and subradiant modes can produce narrow and asymmetric extinction features and dramatic field enhancement [2]. These features make plasmonic Fano-resonance (PFR) be used in ultrahigh sensitive dielectric sensing and new-generation of SES.

We firstly report a particle-substrate system with PFR property which can be used in shell-isolated nanoparticles-enhanced spectroscopy for the in-situ characterization of mono-layer adsorbates on metallic or semiconductor single crystals [3]. Then we discuss the PFR arise from the SERS-active substrates to surface-enhanced infrared spectroscopy (SEIRS) systems with a scattering-type nanostructure coupled with absorbing-type molecules in the infrared regime. By utilizing EM simulations and model analysis, we show the mechanism of a series of Fano-type profiles within SEIR spectra arise from the Fano interference between continuum plasmonic background and discrete vibrational state of molecules [4]. Finally we explore a new type of SEIRS-active nanostructures with charge-transfer mode and gap mode supporting giant and localized EM fields in the mid-infrared regime [4]. Reference: [1] S.-Y. Ding, X.-M. Zhang, B. Ren, Z.-Q. Tian, Surface-Enhanced Raman Spectroscopy (SERS): General Introduction, in: Encyclopedia of Analytical Chemistry; John Wiley & Sons, Ltd (2014). [2] J. Ye, F. Wen, H. Sobhani, J.B. Lassiter, P.V. Dorpe, P. Nordlander, N.J. Halas, Nano Lett., 12 (2012), 1660-1667. [3] S.-Y. Ding, J. Yi, Z.-Q. Tian, To be submitted. [4] J. Yi, S.-Y. Ding, Z.-Q. Tian, To be submitted.


218

Tip-Enhanced Raman Spectroscopy Study on Bimetallic Catalyst Surfaces J.-H. ZHONG1*, X. WANG1, AND B. REN1

1Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), State Key Laboratory of Physical Chemistry of Solid Surfaces, MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China, [email protected]

Heterogeneous catalysis plays an important role in energy storages and conversions. An atomic and molecular level understanding of the surface and interfacial chemistry of heterogeneous catalyst is crucial for designing better catalysts. Recently, the synergistic effect of bi (or multi)-component catalysts has been demonstrated to be important to achieve higher activity and (or) selectivity in (electro, photo)catalysis. Because of the heterogeneous nature on bi (or multi)-component catalyst surfaces, probing the electronic and catalytic properties at a high spatial resolution is desired for understanding the structure-function relationship and catalytic reaction mechanism.

Tip-enhanced Raman spectroscopy (TERS), providing simultaneously the morphology and the fingerprint Raman spectrum, is a promising tool for studying such a surface. Since the enhanced electromagnetic field is localized underneath the tip, TERS can provide sub-10 nm scale spatial resolution, which may help to reveal the local structure correlated electronic and catalytic properties.

Herein, we present a TERS study on bimetallic Pd island/Au(111), Pt island/Au(111), and Pd island/Pt(111) surfaces, tri-metallic Pt island/PdML/Au(111) surface, and various Pt single crystal surfaces, aiming at revealing the structure-function relationship with a high spatial resolution. As an example, sub-monolayer palladium/platinum islands were electrodeposited onto a Au(111) surface to form a well-defined Au-Pd and Au-Pt bimetallic surfaces (Fig. 1a). The coverage of the Pd and Pt was controlled by the charge used for deposition. The phenyl isocyanide molecules (Ph-N≡C) were adsorbed on the surface as a probe of the electronic properties at different positions, because the N≡C triple bond is very sensitive to the electronic structure of metals. Utilizing the high spatial resolution of TERS, we were able to image the surface and probe the distinct electronic properties over different surface sites (Fig. 1b,c). Interestingly, we found that the intensity of the TER signal of the probe molecule is much stronger at the interface/edge sites of Pd island/Au(111) surface than that of the inner sites of a Pd island. This finding unambiguously reflects the unique properties at the interface/edge sites between two metals.

Furthermore, we found that the electronic properties of Au atoms may be modulated by the adjacent Pt atoms, as suggested by the distinct spectral features in the spatially resolved TER spectra. The primary finding in this work suggests that TERS may be a promising technique for studying the heterogeneous catalysis, especially on the understanding of the local structure correlated catalytic properties (activity and selectivity) on bi/tri-metallic surfaces.

In this work, we will also show that TERS can be used to probe the subtle change of the intermolecular interaction of a self-assembled monolayer on Au(111) surface. The combined TERS and electrochemical study provides molecular-level understanding of the structural rearrangement process during the assembly of a pyridine-terminated aromatic thiol on Au(111). Acknowledgement Financial supports from MOST (2011YQ03012406 and 2013CB933703), NSFC (21227004, 21321062, J1310024) and MOE (IRT13036 ) are highly acknowledged. References [1] X. Wang, Z. Liu, M. D. Zhuang, H. M. Zhang, X. Wang, Z. X. Xie, D. Y. Wu, B. Ren, Z. Q. Tian, Appl. Phys. Lett. 91 (2007),

101105 [2] Z. Liu, X. Wang, K. Dai, S. Jin, Z. C. Zeng, M. D. Zhuang, Z. L. Yang, D. Y. Wu, B. Ren, Z. Q. Tian, J. Raman Spectrosc.

40(2009), 1400-1406. [2] Z. Liu, S. Y. Ding, Z. B. Chen, X. Wang, J. H. Tian, J. Anema, X. S. Zhou, D. Y. Wu, B. W. Mao, X. Xu, B. Ren, Z. Q. Tian,

Nat. Commun., 2(2011), 305.

Fig. 1. (a) STM image, (b) schematics for TERS imaging and (c) spatially resolved TER spectra of a Pd island/Au(111) surface.

ACOVS11/ASC5 Book of Abstracts Author Index

219

AUTHOR INDEX

A Adamson, B. D. ....................................................................... 100 Addai-Mensah, J. ...................................................................... 87 Adiba, C. B. ............................................................................. 132 Agrawal, M. ............................................................................. 112 Aguilar, M.-I. .................................................................... 105, 183 Aitchison, J. C. ........................................................................ 205 Aitken, J. B. ............................................................................... 72 Al-Jorani, K. ............................................................................... 41 Allen, L. ................................................................................... 187 Allon, M. .................................................................................. 202 Anan, M. .................................................................................... 58 Ando, M. ............................................................................ 91, 144 Appadoo, D. ................................ 22, 25, 106, 107, 152, 207, 210 Arora, M. .................................................................................. 204 Aruchunan, G. ......................................................................... 107 Arunan, E. ............................................................................... 209 Auchettl, R. ................................................................................ 23 Augustin, M. A. ........................................................................ 131 Austin, C. ................................................................................. 204

B Backsay, G. B. ......................................................................... 103 Bales, A. .................................................................. 149, 161, 182 Bambery, K. ............................................................................... 45 Bambery, K. R. .......................................................... 24, 132, 145 Barnsley, J. E. ......................................................................... 115 Beardall, J. .......................................................................... 50, 93 Beattie, D. A. ................................................................. 24, 64, 87 Beaussart, A. ............................................................................. 87 Bechtel, H. A. .............................................................................. 5 Bedward, T. M. ........................................................................ 140 Bell, T. ..................................................................................... 164 Bell, T. D. M. ............................................................................ 114 Benferhat, R. ................................................................... 126, 150 Best, S. .................................................................................... 210 Bhattacherjee, A. ....................................................................... 97 Bielawski, S. ............................................................................ 208 Bielecki, J. ............................................................................... 132 Bieske, E. J. ............................................................................ 100 Blake, E. .................................................................................. 201 Blakey, I. .................................................................................. 127 Blanch, E. W. ..................................................................... 36, 129 Boonyang, U. ............................................................................. 61 Bordes, L. ........................................................................ 186, 200 Bour, P. ..................................................................................... 36 Bourdet, J. ............................................................................... 137 Bouzaid, J. ............................................................................... 171 Bremmell, K. E. ......................................................................... 64 Brice, A. ................................................................................... 114 Browne, M. A. .......................................................................... 168 Brubach, J. B. .......................................................................... 208

C Calvet, A. ................................................................................... 17 Cao, J. L. ................................................................................. 177 Carter, E. A. ... 39, 45, 72, 153, 155, 166, 168, 172, 202, 204, 205 Casamayou-Boucau, Y. ............................................................ 17 Chakrabortty, S. ........................................................................ 76 Chan, Y. .................................................................................... 76 Chantler, C. ............................................................................. 210 Charoensuk, T. .......................................................................... 61 Chatchawal, P. .......................................................................... 71

Cheah, M. .................................................................................. 26 Chee, S. .................................................................................... 59 Chen, C.-C. ............................................................................... 67 Chen, I.-C. ............................................................................... 189 Chen, L.-W. ............................................................................. 158 Chen, S. .................................................................................... 72 Chen, W. Q. .............................................................................. 81 Cheng, H.-H. ........................................................................... 189 Chiu, M.-J. ............................................................................... 123 Cho, K. ...................................................................................... 56 Choi, C. H. ................................................................................. 57 Christensen, D. ......................................................................... 50 Chu, L.-K. ................................................................................ 123 Chua, L. ..................................................................................... 18 Clare, G. L. .............................................................................. 205 Combes, V. ............................................................................... 39 Cook, P. .................................................................................... 50 Cooke, D. R. ............................................................................ 134 Cortie, M. ................................................................................. 125 Cortie, M. B. ............................................................................ 153 Coughlan, N. J. A. ................................................................... 100 Couprie, M. E. ......................................................................... 208 Cozzolino, D. ............................................................................. 11 Crowley, J. D. .......................................................................... 111 Cui, Y. ................................................................................. 31, 55 Cuisset, A. ............................................................................... 208 Curmi, P. M. G. ....................................................................... 192

D Dai, Y. ....................................................................................... 51 Darwish, T. .............................................................................. 214 Davidson, G. ........................................................................... 134 Davis, J. A. .............................................................................. 192 de Jonge, M. D. ......................................................................... 72 Deacon, G. ................................................................................ 42 Deacon, G. B. ............................................................................ 41 Del Borgo, M. .......................................................................... 183 DelBorgo, M. ........................................................................... 105 Deng, R. .................................................................................... 44 Denman, P. ............................................................................. 127 Dieing, T. ................................................................................. 147 Dietler, G. ................................................................................ 132 Ding, S.-Y. ............................................................................... 217 Dixon, M. W. A. ......................................................................... 71 Dong, J. ........................................................................... 101, 175 Dong, S. .................................................................................... 76 Dowd, A. ................................................ 40, 52, 53, 105, 153, 183 Dredge, P. ....................................................................... 187, 201 Dressel, M. ................................................................................ 82 Ducournau, G. ......................................................................... 208 Dunn, M. .................................................................................... 89

E Ekvall, M. N. .............................................................................. 55 Ennis, C. ............................................................................ 23, 106 Ennis, C. P. ............................................................................... 22 Evain, C. .................................................................................. 208

F Falconer, R. J. ........................................................................... 10 Fang, J. X. ............................................................................... 174 Faulds, K. .................................................................................. 36 Finney, L. .................................................................................. 72 Fisher, K. ................................................................................. 171


220

Flaaten, G. R. .......................................................................... 143 Flannery, E. ............................................................................. 200 Foster, R. ................................................................................. 214 Fowler, S. M. ........................................................................... 118 Franks, G. V. ............................................................................. 87 Fu, S. ............................................................................... 140, 169 Fui, C. ........................................................................................ 43 Fujii, M. ........................................................................................ 8 Fujii, N. ...................................................................................... 77 Fullagar, R. .............................................................................. 200 Fuller, S. .................................................................................. 139

G Gabona, M. G. ......................................................................... 107 Gao, W. ................................................................................... 101 Gao, Z. X. ................................................................................ 174 Gasparini, S. ............................................................................ 155 Gatenby, S. ............................................................................... 59 Geisler, M. ................................................................................. 52 Gembus, A. ............................................................................. 161 Georges, R. ............................................................................. 209 Gidskehaug, L. ........................................................................ 143 Gnansekar, S. P. ..................................................................... 209 Gobet, M. ................................................................................. 209 Goodall, R. A. .......................................................................... 185 Gordon, K. C. .................................................. 111, 115, 120, 170 Graham, D. ................................................................................ 36 Graham, G. ................................................................................ 25 Grau, G. E. ................................................................................ 39 Grøndahl, L. ............................................................................ 154 Guo, W. ................................................................................... 197 Gupta, A. ................................................................................. 112

H Halstead, J. E. ......................................................................... 168 Hamaguchi, H. ................................................................... 91, 144 Han, Q. Y. ........................................................................ 101, 175 Haputhanthri, R. ........................................................................ 42 Harris, H. H. ............................................................................... 72 Hayazawa, N. ............................................................................ 28 Hayes, E. ................................................................................. 200 Hazrin-Chong, N. H. .................................................................. 38 He, E. J. ........................................................................... 101, 175 He, Y. ...................................................................................... 197 Heath, C. H. ............................................................................. 176 Hegde, R. .................................................................................. 31 Heo, W. ..................................................................................... 57 Heraud, P. ................................................................... 71, 93, 132 Hindle, F. ................................................................................. 208 Hinton, D. ................................................................................ 201 Hirschmugl, C. J. ......................................................................... 5 Hlaing, M. M. ..................................................................... 89, 131 Ho, T. T. M. ............................................................................... 64 Holden, P. ................................................................................ 214 Hollricher, O. ........................................................................... 147 Holroyd, S. E. .................................................................. 120, 121 Hopkins, D. L. .......................................................................... 118 Howard, D. L. ............................................................................ 72 Hu, J. M. ...................................................................................... 7 Huangfu, Z. .............................................................................. 197 Huff, G. S. ................................................................................ 111 Hunag, Y.-H. ............................................................................ 158 Hunt, A. ..................................................................................... 18

I Ihee, H. ........................................................................................ 9 Ishibashi, T. ............................................................................... 33

Ishikawa, H. ............................................................................... 77 Ishikawa, T. ............................................................................... 82 Islam, S. .................................................................................. 210 Islam, T. .................................................................................. 210 Itoh, H. ....................................................................................... 82 Iwai, S. ...................................................................................... 82 Iwamura, M. .............................................................................. 79 Iwata, K. .................................................................... 58, 190, 196 Izgorodina, E. I. ......................................................................... 25

J Jack, K. ................................................................................... 127 Jain, A. K. ........................................................................ 167, 181 Japardize, A. ........................................................................... 132 Jearanaikoon, P. ....................................................................... 71 Ji, W. ......................................................................................... 81 Jiang, Y. B. ...................................................................... 177, 179 Jin, X. ........................................................................................ 60 John, L. ................................................................................... 214 Johnston, E. L. ........................................................................ 168 Joo, T. ............................................................... 20, 56, 57, 62, 66 Jörger, M. ................................................................................ 149 Joshi, T. ..................................................................................... 25

K Kable, S. H. ..................................................................... 103, 180 Kandori, H. .............................................................. 46, 48, 95, 98 Kaur, M. ........................................................................... 167, 181 Kawakami, Y. ............................................................................ 82 Kawamukai, M. .......................................................................... 94 Kearley, G. J. .......................................................................... 213 Kelloway, S. J. ......................................................................... 166 Kennedy, B. J. ......................................................................... 204 Kertesz, M. .............................................................................. 164 Keßler, M. ................................................................................ 182 Khan, M. A. ............................................................................. 124 Khoshmanesh, A. ...................................................................... 71 Kiefert, L. ................................................................................... 12 Kim, S. K. ................................................................................ 102 Kirkbride, K. P. ........................................................................ 152 Kishida, H. ................................................................................. 82 Kobayashi, T. ............................................................................ 76 Kondoh, M. ................................................................................ 77 Kong, C. F. .............................................................................. 178 Kononenko, N. ........................................................................ 166 Krasowska, M. ........................................................................... 64 Krayem, N. .............................................................................. 169 Krechkivska, O. ............................................................... 103, 180 Kress, M. ................................................................................. 147 Kubota, S. ................................................................................. 46 Kulik, A. ................................................................................... 132 Kulkarni, K. ...................................................................... 105, 183 Kulshreshtha, C. ........................................................................ 56 Kwiatek, W. M. ................................................................ 132, 145

L Lai, B. ........................................................................................ 72 Lampin, J-F. ............................................................................ 208 Langlois, N. E. I. ...................................................................... 152 Larsen, C. B. ........................................................................... 115 Lasch, P. ................................................................................... 19 Lau, D. ..................................................................................... 199 Lau, I. C. .................................................................................. 135 Laukamp, C. ............................................................................ 135 Lay, P. A. ............................................... 39, 45, 72, 153, 155, 204 Lee, G. ...................................................................................... 62 Lee, H. K. .................................................................................. 30


221

Lee, J. .................................................................... 39, 45, 72, 204 Lee, K. L. K. ............................................................................. 180 Lee, M. R. .................................................................................. 55 Lee, S. ..................................................................................... 147 Lee, S.-Y. ................................................................................ 194 Lee, W. W. ................................................................................. 67 Lee, Y. H. .................................................................................. 31 Lee, Y.-P. ................................................................................ 158 Lekka, M. ................................................................................. 132 Lekki, J. ................................................................................... 145 Lennard, C. ...................................................................... 139, 201 Leong, J. .................................................................................. 155 Levina, A. .................................................................... 45, 72, 155 Lewis, S. W. ............................................................................ 141 Li, B. .......................................................................................... 17 Liang, C. .................................................................................... 44 Liang, L. ..................................................................................... 44 Lin, H.-P. ................................................................................... 67 Lin, J. J. ................................................................................... 157 Lin, K.Q. ...................................................................................... 6 Lin, L. ......................................................................................... 41 Ling, X. Y. ...................................................................... 30, 31, 55 Lipec, E. .................................................................................. 132 Lipiec, E. ............................................................................ 42, 145 Liu, B. ........................................................................................ 51 Liu, B. J. ...................................................................................... 6 Liu, F.-Y. .................................................................................... 67 Liu, G. F. .................................................................................. 213 Liu, H. ...................................................................................... 173 Liu, J.-Y. .................................................................................... 60 Liu, Y. ................................................................................ 31, 180 Lo, W. K. C. ............................................................................. 111 Logan, M. .................................................................................. 14 Loh, Z.-H. .................................................................................. 76 Lucas, N. T. ............................................................................. 115 Luong, S. ................................................................................. 200 Lyu, R. ....................................................................................... 51

M Maas, P. .................................................................................. 161 MacWilliams, S. V. .................................................................... 64 Majzner, K. ................................................................................ 19 Mak, R. ...................................................................................... 72 Manceron, L. ........................................................................... 208 Manefield, M. ............................................................................. 38 Maric, M. .................................................................................. 141 Marjo, C. E. ......................................................................... 38, 59 Markworth, P. .......................................................................... 100 Martin, D. E. .............................................................................. 24 Martin, M. C. ................................................................................ 5 McArthur, S. L. .......................................................................... 89 McDowell, A. ........................................................................... 170 McGoverin, C. ......................................................................... 121 McLeod, A. I. ..................................................................... 72, 155 McMurtrie, J. ............................................................................ 171 McNaughton, D. ............................ 41, 42, 71, 107, 131, 132, 207 Measday, D. ............................................................................ 185 Mechler, A. ...................................................................... 105, 183 Medcraft, C. ..................................................................... 106, 207 Miyamoto, M. ............................................................................. 77 Mizuno, M. ............................................................... 46, 48, 77, 98 Mizutani, Y. .............................................................. 46, 48, 77, 98 Mohan, H. ........................................................................ 167, 181 Mohri, G. .................................................................................. 190 Mole, R. A. ............................................................................... 213 Morley, M. W. .......................................................................... 200 Morris, C. ................................................................................... 17 Moseley, G. W. ........................................................................ 114 Mouret, G. ............................................................................... 208 Muller, E. A. ................................................................................. 5

Murphy, T. D. .......................................................................... 201 Myers, M. ................................................................................ 176

N Naito, Y. .................................................................................... 82 Nakashima, S. ......................................................................... 130 Namajima, A. ............................................................................. 98 Nasse, M. J. ................................................................................ 5 Nauta, K. ......................................................................... 103, 180 Nazir, A. .................................................................................. 192 Nel, P. ..................................................................................... 199 Ng, L. L. ................................................................................... 107 Nieuwoudt, M. K. ..................................................................... 121 Noake, E. ................................................................................ 199 Noothalapati, H. ........................................................................ 94 Novelli, F. ................................................................................ 192 Nozaki, K. .................................................................................. 79 Nunn, J. P. .............................................................................. 152

O O’Riley, H. ................................................................................. 72 Ogura, T. ................................................................................. 130 Ohshima, Y. ............................................................................ 195 Ohta, N. ..................................................................................... 84 Oikawa, K. ................................................................................. 48 Ojha, R. ..................................................................................... 42 Okamoto, H. .............................................................................. 34 Okuno, M. .................................................................................. 33 Olmon, R. L. ................................................................................ 5 Ostovar pour, S. ........................................................................ 36 Otieno-Alego, V. ...................................................................... 165

P Parchansky, V. .......................................................................... 36 Parkinson, D. Y. .......................................................................... 5 Parkinson, D. Y. ...................................................................... 132 Pas, E. ....................................................................................... 50 Patcharaporn, T. ....................................................................... 71 Paterson, D. .............................................................................. 72 Pedireddy, S. ............................................................................. 31 Pejcic, B. ................................................................................. 176 Perez-Guita, D. ......................................................................... 71 Perlmutter, P. .................................................................. 105, 183 Petrou, K. .................................................................................. 93 Phang, I. Y. ......................................................................... 30, 55 Phan-Quang, G. C. ................................................................... 30 Phillips, D. L. ............................................................................. 74 Pirali, O. .................................................................................. 208 Plathe, R. ................................................................................ 106 Prezhdo, O. V. ........................................................................... 76 Prinsloo, L. C. .......................................................................... 200 Puskar, L. .......................................................................... 24, 187

Q Qu, H. ........................................................................................ 44

R Rajakumar, B. ......................................................................... 160 Rajkumar, A. ........................................................................... 205 Ramanaidou, E. R. .................................................................. 137 Raschke, M. B. ............................................................................ 5 Rasheed, M. P. ......................................................................... 65 Reade, W. J. ........................................................................... 202 Ren, B. .......................................................................... 6, 60, 218 Rey, P. F. ................................................................................ 172


222

Rich, A. M. ........................................................................... 38, 59 Richard, C. J. E. ........................................................................ 64 Richards, G. H. ........................................................................ 192 Riley, B. J. ............................................................................... 139 Rintoul, L. ................................................................................ 171 Roberts, G. E. .......................................................................... 172 Roberts, R. .............................................................................. 200 Robertson, E. G. .......................................................... 22, 23, 207 Rocks, L. ................................................................................... 36 Rodemann, T. .......................................................................... 134 Rooney, J. S. ........................................................................... 170 Roozbeh, A. ............................................................................. 192 Roussel, E. .............................................................................. 208 Roy, P. ..................................................................................... 208 Ruggeri, F. S. .......................................................................... 132 Russell, R. ............................................................................... 214 Ruzi, M. ....................................................................... 22, 23, 207 Ryder, A. G. ............................................................................... 17

S Sackett, O. ................................................................................. 93 Sadler, P. J. ............................................................................... 25 Safianowicz, K. M. ................................................................... 164 Safitri, A. ............................................................................ 45, 155 Sasaki, T. .................................................................................. 82 Sawicki, M. .............................................................................. 187 Schmidt, H. .............................................................................. 118 Schmidt, T. W. ................................................................. 103, 180 Schmidt, U. .............................................................................. 147 Scholes, C. A. .......................................................................... 116 Seoudi, R ................................................................................. 105 Seoudi, R. S. ........................................................................... 183 Seshadri, S. ............................................................................... 65 Sharma, S. .............................................................. 134, 167, 181 Shen, A. G. .................................................................................. 7 Shen, W. ...................................................................................... 6 Shillito, G. ................................................................................ 115 Shinohara, M. .......................................................................... 190 Shinzawa-Itoh, K. .................................................................... 130 Siauw, M. ................................................................................. 127 Simpson, M. C. ........................................................................ 121 Singh, P. S. ..................................................................... 167, 181 Sirisathitkul, C. .......................................................................... 61 Smith, G. P. S. ......................................................................... 120 Smith, J. A. .............................................................................. 168 Smith, N. .................................................................................. 165 Smith, N. I. ................................................................................. 92 Smith, T. A. .............................................................................. 116 Smith, T. M. ............................................................................. 204 Smulevich, G. .............................................................................. 2 Soleimaninejad, H. .................................................................. 116 Son, J. ....................................................................................... 56 Spiccia, L. .................................................................................. 25 Spikmans, V. ................................................................... 139, 201 Srinivasulu, G. ......................................................................... 160 Stämmler, M. ............................................................................. 19 Stampfl, A. P. J. ....................................................................... 212 Stockdale, D. ............................................................................. 53 Stoddart, P. R. ........................................................................... 89 Stork, B. ..................................................................................... 40 Strachan, C. J. ......................................................................... 170 Stringer, D. N. ............................................................................ 64 Stuart, B. H. ............................................................................... 18 Suden, M. ................................................................................ 169 Sutikna, T. ............................................................................... 200 Suzuki, S. ................................................................................ 154 Swarbrick, B. ........................................................................... 143 Szwaj, C. ................................................................................. 208

T Tahara, T. .................................................................................. 79 Takaya, T. ......................................................................... 58, 190 Takeuchi, S. .............................................................................. 79 Tam, K. ............................................................................ 149, 182 Tammaro, J. ............................................................................ 208 Tan, H.-S. .................................................................................. 75 Tan, T. L. ................................................................................. 107 Tanaka, Y. ................................................................................. 82 Tao, X. T. ................................................................................ 213 Tarr, S. .................................................................................... 155 Thomas, P. S. ........................................................................... 18 Tian, C. F. ............................................................................... 174 Tian, Z.-Q. ............................................................................... 217 Tilley, L. ..................................................................................... 71 Tjiu, W. W. ................................................................................. 31 Tobin, M. J. ................................................... 24, 45, 72, 132, 145 Tordeux, M. A. ......................................................................... 208 Torrence, R. ............................................................................ 166 Treasure, A. ............................................................................ 165 Trevorah, R. ............................................................................ 210 Trivedi, D. .................................................................................. 76 Troy, T. P. ............................................................................... 103

U Uddin, N. ................................................................................... 57 Uddin, S. ................................................................................... 10

V van Bronswijk, W. .................................................................... 141 van de Ven, R. ........................................................................ 118 van der Salm, H. ..................................................................... 115 van der Walle, C. F. .................................................................. 10 Vernooij, R. R. ........................................................................... 25 Vogel, C. ................................................................................. 145 Vogt, S. ..................................................................................... 72 Vongsvivut, J. ............................................................................ 24

W Walker, G. S. ........................................................................... 152 Wallace, V. P. ............................................................................ 10 Wang, C. C. ............................................................................... 85 Wang, F. .................................................................................. 210 Wang, J. .................................................................................. 197 Wang, L. .................................................................................... 51 Wang, P. ................................................................................. 174 Wang, R. ................................................................................. 135 Wang, X. ....................................................................... 6, 51, 218 Wang, Y. ................................................................................. 197 Wang, Y.-I. .............................................................................. 158 Wang, Z. .................................................................................. 197 Wang, Z. J. .............................................................................. 175 Wategaonkar, S. ....................................................................... 97 Waterland, M. R. ....................................................................... 86 Webb, H. K. ............................................................................... 24 Wells, M. A. ............................................................................. 137 Wen, B. ..................................................................................... 39 Wentrup-Byrne, E. ................................................................... 154 Westad, F. ............................................................................... 143 Whelan, D. ...................................................................... 132, 145 Whelan, D. R. .......................................................................... 114 Wilk, K. E. ................................................................................ 192 Williams, D. E. ......................................................................... 121 Wong, A. ................................................................. 106, 107, 207 Wongwattanakul, M. .................................................................. 71 Wood, B. R. ............................... 25, 41, 42, 50, 71, 131, 132, 145


223

Wood, M. ................................................................... 72, 155, 166 Worthy, A. ................................................................................ 171 Wu, D.-Y. ................................................................................... 60 Wu, L. ........................................................................................ 72 Wu, Y. C. ................................................................................. 194 Wuhrer, R. ....................................................................... 187, 201

X Xiao, L. .................................................................... 125, 140, 169 Xie, T. Y. .................................................................................. 174 Xiong, Q. ................................................................................. 110 Xu, M. ...................................................................................... 197 Xu, Q.-H. ................................................................................. 216 Xu, S. ................................................................................... 43, 44 Xu, W. .................................................................................. 43, 44

Y Yabumoto, S. ........................................................................... 144 Yamamoto, K. ............................................................................ 82 Yamamoto, T. ............................................................................ 94 Yan, L. X. ................................................................................. 175 Yan, X. S. ................................................................................ 179 Yang, C. .................................................................................. 173 Yang, J.-S. ............................................................................... 189 Yang, L. ..................................................................................... 43 Yao, H.-H. ................................................................................ 189 Yeap, K.-Y. ................................................................................ 87

Yeow, E. K. L. ........................................................................... 16 Yi, J. ........................................................................................ 217 Ying, D. Y. ............................................................................... 131 Yonemitsu, K. ............................................................................ 82 Yoon, E. .................................................................................... 66 Yoshikawa, S. ......................................................................... 130 Yu, D. H. .................................................................................. 213 Yuan, Y. .................................................................................. 179

Z Zachmann, G. ................................................................. 149, 182 Zeitler, J. A. ............................................................................... 10 Zeng, Z. C. .................................................................................. 6 Zhan, D.-P. ................................................................................ 60 Zhang, C. Y. ............................................................................ 175 Zhang, J. ........................................................................... 60, 132 Zhang, M. .................................................................................. 19 Zhang, Z. L. ............................................................................. 175 Zhao, B. ................................................................................... 194 Zheng, H. R. .................................................................... 101, 175 Zheng, R. K. ............................................................................ 124 Zhong, J.-H. ...................................................................... 60, 218 Zhou, F. ..................................................................................... 81 Zhou, X. D. .................................................................................. 7 Zhu, S. ....................................................................................... 52 Zhu, S. L. ................................................................................. 125 Zong, C. ...................................................................................... 6

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