Nanomaterials for Bio, Chemical and Gas Sensing Applications

By

Vasuda BhatiaLead Scientist, Amity Institute of Renewable and Alternative Energy, Amity University

Outline

Applications

•Which Nanomaterial for What?

•Chemical: Smoke, pH, Alcohol, …

•Bio: DNA, Cholesterol, …

Sensors

•Types

•Chemical/Biological Properties

•Development

•Detection/Use

Nanomaterials

•Types: Carbon, Si, Others …

•Properties

•Synthesis

2

INTRODUCTION Sensor & Nanomaterials Overview

SECTION 1 Carbon Nanomaterials Based Sensors

SECTON 2 Nanoparticles Based Sensors

SECTION 3 Si Nanowires

The Sensor Universe

Calorimetry

Acoustic Wave

Chemiresistors

Spectroscopy

Ellipsometry

Interferometry

Electrical

OpticalPhysical

CHEMICAL / BIO PROPERTIES

Temperature

Strain

Pressure

Torque

Mass

Fluorescence

Raman

Luminescence

Phosphorescence

Resistance

Dielectric

Current

Electrochemical

Field Effect Transistors

Cyclic Voltammetry

Refractive Index3

Material Properties Detection Techniques

Image courtesy of www.rusnano.com

Classification of Nanomaterials

• Quantum Dots and Nanoparticles

• 1 to 100 nm

• Exceptional optical properties due to electron confinement that produces quantum effects

Nanotubes and nanowires

Characteristic diameter 1 to 100 nm

Metallic: Ni, Pt, Au; Semiconducting: Si, InP, GaN ; Insulating: SiO2, TiO2. and Molecular nanowires

One unconfined direction for electrical conduction

Nano-textured surfaces or thin films

Electrons confinement defines interaction with EM radiation

Electrons perpendicular to substrate affect wave-function & density of states

Phonons thermal transport

□ Bulky materials with all dimensions above 100 nm

□ Crystalline materials, polycrystalline materials, and amorphous materials.

4

Carbon Nanomaterials Based Sensors

• Introduction to Carbon Nanomaterials

• Carbon Nano Tubes (CNTs) and Their Functionalization

• CNT Synthesis Methods

• Electrostatic Functionalization (f-MWCNTs) and Chemical Sensors

• Molecular Modification of f-MWCNTs and Chemical Sensors

• Composites of f-MWCNTs with Polymer and Amorphous Material for Sensing

• Biomolecule Detection with CNTs

• Graphene Based Sensors

5

SECTION 1:

Graphitesp2 hybridization and planar

Diamondsp3 hybridization and cubic

6

The Wonderful World of Carbon

Source: education.mrsec.wisc.edu

Carbon Nano Tubes: Applications

7

www.nanowerk.com

www.nanowerk.com www.nanointegris.com www.soci.org

Source: Julius-Maximilians-Universität Würzburg

Asdn.net

www.oled-info.com/samsung-youm

A. Defect-group functionalization,

B. Covalent sidewall functionalization

C. Non-covalent exohedral functionalization with surfactants

D. Non-covalent exohedral functionalization with polymers

E. Endohedral functionalization with, for example, C60

Source: Angew Chem Int Ed Engl. 2002; 41(11):1853-9

Surface Modification via Functionalization sp2 + sp3 character: cylindrical

Nanotube formation eliminates dangling bonds

in graphene and leads to decrease in total energy

100x stronger than steel, 30x stronger than carbon fiber

Remarkable electrical conductivity

Ionic conductivity depends upon the chirality

Thermal stability and reliability up to 4000K

Chemically active and highly sensitive

Carbon Nano Tubes: Structure & Functionalization

8

Source: www.intechopen.com

Arc-Discharge

Laser Ablation

Chemical Vapor Deposition

Flame Synthesis

Carbon Nano Tubes: Synthesis

9

V. Bhatia, et al, Int. J. Nanosci, Vol 8, pp 443-453, 2009.

Electrostatic Functionalization of MWCNTs & Chemical Vapor Sensing

Adsorption-Desorption Process

Charge Transfer Mechanism

10

Carbon Nanomaterials Based Sensors

• Electrostatic Functionalization

• Decoration with Nanoparticles

1. Sensors based on Nanoparticles Decorated Multi-Walled CNTs

• Polymer Composites

• Amorphous Material Composites

2. Sensors based on Composite Nanomaterials

• Glucose Sensor based on CNT

• Cholesterol Sensor based on Nano-graphitic Oxide

3. Non-enzymatic Bio-Sensors based on Nanomaterials

11

In-Situ Decoration of Electrostatically Functionalized Multiwalled Carbon Nanotubes with β-Ni(OH)2 Nanoparticles

Richa SAGGAR, Vasuda BHATIA, Prashant SHUKLA, Nitin BHARDWAJ, Vinod K JAIN; Sensors and Transducers, Vol. 146, pp. 28-35, 2012

12

CNTs

-10

0

10

20

30

40

50

60

0 1000 2000 3000 4000 5000 6000

Time (sec)

%

Resi

sta

nce C

ha

ng

e

Dichloroethane

Toulene

Chloroform

Methanol

Benzene

f-CNTs

-10

0

10

20

30

40

50

60

70

0 1000 2000 3000 4000 5000 6000

Time (secs)

%

Resi

sta

nce C

ha

ng

e

Dichloroethane

Toulene

Chloroform

Methanol

Benzene

Organic Vapor Detection using f-MWCNTs/PMMA Composites

Detection based on swelling of polymer matrix on absorption of organic vapors that increases the distance between adjacent nanotubes.

Change in conductivity of MWCNT/polymer upon exposure to chemical vapors occurs as a result of the charge transfer induced by adsorption of polar organic molecules.

Functional groups provided interfacial adhesion and a better dispersion of f-MWCNTs in the polymer matrix in turn better conducting channel through the PMMA matrix.

13

‘Electrostatically Functionalized Multiwalled Carbon Nanotube/ PMMA Composite Thin Films For Organic Vapor Detection’, P. Shukla, V. Bhatia, V. Gaur, V. K. Jain, Polymer-Plastics Technology and Engineering, 50, 1179-1184, 2011.

MWCNTs in the Pores of Cementitious Material

DC Transient measurements - Keithley Electrometer 6514

AC Impedance measurements - Agilent E4890A Impedance Analyzer

Smoke Generation- 30 ml Paraffin Oil of Mol Wt. 325 gm/mol & r 0.8gm/cc

Multiwalled Carbon Nanotubes Reinforced Portland Cement for Smoke Detection

P. Shukla, V. Bhatia, V. Gaur, R. K. Basniwal, B. K. Singh, V. K. Jain; Solid State Phenomena, Vol. 185, pp. 21-24, 2012. 14

0 250 500 750 1000 1250 1500 1750 20000

10

20

30

40

50

Recovery

SaturationExposure to Ambient

%S

(-v

e)

Time (sec)

0% CNT

0.17% CNT

0.34% CNT

0.68% CNT

s

dc A )( Jonscher Equation for Ionic Conductivity

Dimensionless frequency parameter, S : 0.14-0.28

In cementitious material conduction through flow of ions: Ca2+, Na+, K+ or OH- through the porosity of the material.

In MWCNTs conduction through flow of free electrons.

In MWCNTs/Cement conduction via: continuous network of conductive fiber in series with flow of ions.

Under smoky environment : charged particles interact with MWCNTs and provide enhanced ionic conductivity

15

Electrochemical Sensor for Biomolecule Detection

Ferri et al. J Diabetes Sci Technol. 2011;5(5):1068-76.

CNTs act as nano-connectors between the electrode and redox cofactors ( e.g.. FAD) center due to their similar size.

The electrons are transported along distances greater than 150 nm and the rate of electron transport is controlled by the length of SWCNTs.

Covalently attach FAD to the SWCNT ends and then GOD reconstituted at the immobilized FAD

Glucose + GOD(ox) → Gluconic acid + GOD(red)

GOD(red) + 2M(ox) → GOD(ox) + 2 M(red) + 2 H+ 2M(red) → 2M(ox) + 2e−

M(ox) and M(red) are the oxidized and reduced forms of the mediator.

The reduced form is reoxidized at the electrode, giving a current signal which is proportional to the glucose concentration.

Artificial mediators, like ferrocene derivatives, ferricyanide, transition-metal complexes act as mediators.

16Wang, Chem. Rev. 2008, 108, 814−825

Cyclic voltammogram study

Stability test

Palladium Nanoparticles Decorated Electrostatically Functionalized MWCNTs Non Enzymatic Glucose Sensor

Calibration plotInterference study at-0.4V

Amperometry response

17

B. Singh et al. Sensors and Actuators A 220 (2014) 126–133

Perreault et al Chem. Soc. Rev., 2015,44, 5861-5896

ul Hasani et. al. J Biosens Bioelectron 2012

Novoselov et al Nature 490, 192-200, 2012

Graphene Based Sensors

18

Hummers Process

Source: www.comsol.comCVD Growth

Epitaxial Growth Source: www.rug.nl

Liu et. al. Adv. Funct. Mater. 2008, 18, 1518–1525Electrochemical

Synthesis Processes

19

3400 cm-1 : O-H stretching1755 cm-1 : C=O stretching1654 cm-1 : Unoxidized graphitic

vibrations1207 cm-1 : C-OH stretching1060 cm-1: C-O stretching

0 10 20 30 40 50 60 70 80

0

500

1000

1500

2000

2500

3000

3500

Inte

nsit

y /cp

s

2 theta /degree

(002)

(004)

Cholesterol + O (-attached to nano-graphite oxide) 4- Cholesten-3-one + H2O2

H2O2Electrode O2 + 2H+ + 2e-

Graphite Oxide based Non-Enzymatic Cholesterol Sensor

Nano-graphite oxide synthesized from graphite flakes using Hummer’s method

20

Bhawana, Nitin Bhardwaj, Vinod K. Jain and Vasuda Bhatia; Physics of Semiconductor Devices; 17th International Workshop on Physics of Semiconductor Devices 2013; Springer International Publishing; pp. 531-534, 2014.

Nanoparticles Based Sensors

• Synthesis

• Colorimetry Based Biosensor

• Electrical Based Biosensor

• Magnetic NPs for Sensing Applications

• Chemiresistor

21

SECTION 2:

Nanoparticles Based Sensors

22

Target placed in a solvent Exposure to high energy laser beam Target vaporizes Vapors condense in solvent Nanoparticles are formed Good for any combination of target and

solvent Create both Metallic and Ceramic

nanoparticles No protecting ligand is required, positive

charge on the nanoparticle surface protects from agglomeration.

High purity nanoparticles are synthesized

Laser Ablation

Ingredients: Solvent + Reducing Agent

Use Surface-controlling Agents for uniform particle sizes

Use Stabilization Agent to control the growth rate & particle size

+ Prevents agglomeration and increases nanoparticle solubility

Gold(III) chloride trihydrate (HAuCl4·3H2O) and trisodium citrate dihydrate(Na3Ctr·2H2O)

Chemical Method

Burst method : Brust and Schiffrin in early 1990s

Attachment of self-assembled thiolatedmonolayer on the surface of gold NPs with no external assistance due to formation of an extremely strong covalent bond.

Encapsulated Metal NPs

Synthesis of Nanoparticles

23

Nanoparticles Based Biosensors

Colorimetric Detection of DNA Nanoparticles are modified via a thiol bond with single stranded DNA complementary to the target DNA The modification of the nanoparticles affects the amount of light absorbed by the solution, compared to the un-modified (or bare)

nanoparticles When the target DNA analyte is added to the solution, aggregation occurs resulting in the cluster formation of nanoparticles Changes in absorbance of the solution are detected

Mirkin et al., Nature, 1996, 382, 607-609 Mancuso et al., Nanoscale, 2013,5, 1678-1686 24

Magnetic Nanoparticles Based Detection

Detection system has magnetic micro particle probes with antibodies that specifically bind a target of interest, nanoparticle probes that are encoded with DNA that is unique to the protein target of interest and antibodies that can sandwich the target captured by the microparticle probes.

In this configuration, magnetic separation of the complex probes and target is followed by dehybridization of the DNA on the nanoparticle probe surface.

This allows the detection of the target protein by identifying the DNA sequence released from the nanoparticle probe. Nam et al. , Science, 2003, Vol. 301, pp. 1884-1886

Electrical Detection of DNA

Target DNA is captured in the gap between two electrodes

Following capture, silver is plated onto the NPs

The gap between the two electrodes is bridged due to plating of silver NPs

This allows current flow

The current flow is translated into DNA detection

Park et al., Science, 2002, Vol. 295, Issue 5559, pp. 1503-1506

25

Chemiresistors Based on Molecularly Modified NPs

• Chemical interaction between sensing material and analyte

• Detection of change in Electrical Resistance

• Molecularly modified NPs (such as organic ligands) are assembled between metallic electrodes

• Absorption of analytes by organic ligands

• NPs conduct electrical current between electrodes

• Mechanisms of detection:• Film-swelling: increases the resistance due to an increase in the inter-particle tunnel

distance; and

• An increase in the permittivity of the organic matrix around the metal cores that decreases the resistance.

• Critical parameters• Organic ligand chain length – sensitivity increase with chain length.

• Film morphology determines percolation path.

• Linking molecules between NPs control film swelling.

• NP shape – spherical particles provide the voids in the film whereas cubic shaped NPs show the least voids in the film and increased sensitivity.

No direct linkage between the adjacent NPs and, therefore, no current conduction

Island of NPs that upon exposure to analytes swells. Swelling reduces distance between NPs that increase conduction.

NPs along percolation pathway.

Joseph et al., J. Phys. Chem. C, 2008, 112 (32), pp 12507–12514

26

Si Nanowires

• Synthesis

• FET Based Sensors – Theory

• FET Based pH Sensors

• FET Based Explosive Sensors

• Tunnel FET Sensors

27

SECTION 3:

http://www.nist.gov/public_affairs/techbeat/tb2005_0630.htm#transistors

Si Nanowires Based Field Effect Transistor (Si NW FET)

The reaction of SiCl4 and H2 vapor phases leads to synthesis of NWs in solid phase

Gold-silicon liquid droplet acts as catalyst

https://en.wikipedia.org/

Bottom-Up ApproachVapor–Liquid–Solid Method (VLS)

Top-Down Approach

Si Wafer

Phoresist

Exposure with UV under followed by etching

PR removal and Final Structure

SYNTHESIS

28

Si NW Applications: pH Sensor Cui et al, Science 293, 1289 (2001)

Surface modifications of Si NW oxide with 3-aminopropyltriethoxysilane (APTES) (A) provides protonation and deprotonation where changes in the surface charge can chemically gate device.

Real time conductance measurements(B) demonstrate linearity over the range 2 to 9 (c).

The conductance of unmodified Si NW versus pH is non-linear (D).

Surface terminating in both -NH2 and -SiOH groups with APTES modifications.

At low pH, the -NH2 group is protonated to -NH3+ and

acts as a positive gate, which depletes hole carriers in the p-type SiNW and decreases the conductance.

At high pH, -SiOH is deprotonated to –SiO-, which increases conductance.

The observed linear response due to the total surface charge density (versus pH) of the combined acid and base behavior of both surface groups.

29

Si NWs exhibit sensitive and fast electrical responses to vapors of common nitro explosives and their degradation by-products.

The surface of the silicon nanowires modified by plasma treatments with hydrogen and oxygen.

Plasma cleaning provides more adsorption/binding sites for the target molecules.

The oxygen-plasma prepared surface with Si-OH groups that might form charge transfer complexes with the nitro groups of nitro-containing explosives to strengthen the chemiresistive response.

The sensitivity is found to increase when the cross-section of the nanowires decreases.

Wang et al., Nanoscale, 2012,4, 2628-2632Si

Explosive Detection Si NW-Tunnel FET Biosensors

Si NW surface functionalized with specific receptors to capture the target biomolecules.

The charged biomolecules induce a gating effect and modulate the band-to-band tunneling (BTBT) barrier and hence the tunneling current.

When VG = 0, the TFET device is in the off state, and the tunneling barrier is so large that BTBT is suppressed

Applying a negative (positive) gate voltage reduces the tunneling barrier for elections (holes) inducing high conduction.

The charged biomolecules captured by receptors on Si NW-TFET further reduce the tunneling barrier and increase the BTBT current.

Gao et al., Scientific Reports 6, Article number: 22554 (2016)

30

Si NW Sensor Applications

31

Research TeamDr. V. K. Jain, Director Amity Institute of Advanced Research and Studies Present Team Members:Dr. Prashant Shukla (Assistant Professor)Dr. AbhishekhVerma (Assistant Professor)Mr. RupeshBasniwal(Assistant Professor)Nitin Bhardwaj (Lab Assistant)Past Team Members: Dr. Bhawana Singh (past PhD Scholar)Mr. Vikesh Gaur (Lecturer and Presently Self Employed )Dr. B. K. Singh (Lecturer and Presently PDF at University of Aveiro, Portugal)Ms. Richa Saggar(Research Scholarand Presently Marie Curie Research Fellow at Institute of Physics of Materials Academy of Sciences of Czech Republic)Funding Agencies: DST, DRDO and MOM