Chapter 10Applications of Nanotechnology:

Biology & Nanotechnology

NANO 101Introduction to Nanotechnology

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Overview• Much biology is mediated in the 1-100 nm range• Structures and sizes• Inspiration for Self Assembly and Molecular Machine

concepts

Nanotech and Biology

BioNanotechnology: • use of biology (biological molecules) in nanotech • use of biology as a model for a nanotechnology

system• Ex. DNA computing

Nanobiotechnology: • use of nanostructures to enhance biology or

biotech• use of nanotechnology for creating or improving

biotech systems or processes• Ex. Lab-on-a-chip assays 3

Lab on a Chip• Combining all lab

functions in one device

• Soft lithographyPDMS casting

Source: Nature Video

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Lab on a Chip: Research

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Lab on a Chip: Diagnosis

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How Biology “Feels” on the Nanoscale

• Hydro environments v. carbon-based life

• What are these tiny species in a cell?• Sugars (carbohydrates)• Fatty acids (lipids)• Nucleotides (DNA)• Amino Acids (proteins)

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CarbohydratesRoles:

1. Mechanical support (large carbohydrates, ex. cellulose)

2. Metabolized and used for energy

• Sugars are basic building blocks• general formula: (CH2O)n

• examples• glucose (n= 6)

• fructose (n= 6)

• ribose (n= 5)

• loop on themselves to form rings• rings attach to make chains of many types

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Basic Carbohydrate Examples

OH

O

H OH

OH H

H OH

H OH

OH

OH H

H OH

H OH

O

OH

OH

O

H OH

H OH

H OH

glucose fructose ribose

O

OHH

HH

OHOH

H OH

H

OH

O H

OHH

OH

H

OH

H

OH

O OH

H

OH

OH

HH

OH

OH

chain formation: sugarssimplest: sucrose

monosaccharides; disaccharides; polysaccharides…

Complex Carbohydrate Examples

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http://www.elmhurst.edu/~chm/vchembook/547cellulose.html

http://guweb2.gonzaga.edu/faculty/cronk/biochem/C-index.cfm?definition=chitin

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LipidsRoles:

1. Energy (concentrated energy reserve)

2. Structural (ex. membranes)

• Fatty acids are basic building blocks• long carbon chains with COOH head group• amphiphilic interesting self-assembled

structures• saturated; monounsaturated;

polyunsaturated…

Oleic acid

Source: Univ. of Calgary

Phospholipids• Pair of fatty acids, connected by glycerol and

phosphate group• Usually also bonded to a small hydrophilic molecule• Capable of self-assembly and self-repair!

12Source: PB Works

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DNARoles:

1. Stores, replicates information

2. Along with RNA and proteins, translates info into product

• Nucleotides are basic building blocks• Deoxidized ribose rings chained together with

phosphate bridges• Pendant on the ribose rings are the four “bases”

• Specific hydrogen bonding based pairing

N

N

NH

N

NH2

N

NH

NH2

O N

NH

NH

N

NH2

O

NH

NH

O

O

CH3

adenine cytosine guanine thymine

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Self- assemble

d DNA structure

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Base pair hydrogen bonding

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DNA - chromosome structure

DNA Transcription

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RNA Transcription

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ProteinsRoles:

Perform many many many roles

Examples include: hormones; transportation of other molecules; enzymes; detecting signals; structural support

• Amino Acids are basic building blocksCarbon connected to:

• NH3 (amino group)

• COOH (carboxyl group)

• Side chain

• Hydrogen

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The 20 amino acids

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Protein Structure

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Globular Protein Structure

Applications of BioNanotech:Molecular Motors

ATP Synthase:• as protons flow through membrane, spins• in cells, this mechanical energy is used for the ADP

ATP rxn

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http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookATP.html

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ATP Rotor and Attached Sphere

Constructing Biological Motor Powered Nanomechanical Devicesby

Carlo Montemagno*, George Bachand, Scott Stelick, Marlene Bachand

http://www.foresight.org/Conferences/MNT6/Papers/Montemagno/

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DNA (Genomic) microarraysSynthesis of Gene ChipsBiomolecular Engineering Volume 22, Issues 5–6, December 2005, Pages 173–184

http://www.bio.davidson.edu/genomics/chip/chip.html

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Gene Chips

http://www.bio.davidson.edu/Courses/genomics/chip/chip.html

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Application of BioNanotech:Scaffolded DNA Origami

Use short single strands of DNA (“staples”) to direct folding of long strands of DNA to make nanostructures

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Application of BioNanotech: Fluorescence tagging

• Fluorescence tag attached to cDNA– Organic dyes

• Cy3 and Cy5

– Quantum Dots

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Application of NanoBiotech: Metal Nanoparticle/Film Binding

Assays• Surface plasmon resonance

– Colorimetric shifts indicate binding

• Can be accomplished using 10-100 nm Au or Ag particles or films

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Protein BindingBasic phenomenon in much of biology

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Protein Microarray Screening

Surface Plasmon Resonance

The optical properties (reflectivity or spectral absorption) of a metal thin film or particle is determined by the size, shape, and number of any molecules attached to it.

Input Light Output Light

glass

gold

specular angle specular angle

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Protein Microarray Screening

At some particular angle or wavelength, most of the input light energy will be converted to a plasmon

Input Light output light

Specular Angle specular angle

specular angle or wavelength

reflect

ivit

y

reflectivity = output/input

Reflectivity minimum is dependent on type of molecule bonded

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Protein Microarray Screening

Monitor SPR curves over time to track binding events

Raman Spectroscopy

• Gives information about vibrational (low energy) states 35

Surface Enhanced Raman Spectroscopy

• Noble metal nanoparticles act as antennas

36Phys. Chem. Chem. Phys., 2013, 15, 5312-5328

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Nanoparticle Photothermal Therapy

Surface Plasmon Resonance effect using a metal nanoshell in the IR “water window”

http://nano.cancer.gov/resource_center/nanotech_nanoshells.asp

Magnetism

• Magnetic field induces changes in alignment of electron spins in a substance

• Paramagnetism: unpaired spin magnetic moment is alligned with applied field

• Ferromagnetism: unpaired spins align in absence of magnetic field

• Diamagnatism: a magnetic moment opposing the applied field from paired electrons

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Magnetic Memory

• Non-volatile (is not lost when power is removed)– Co – alloy material

• Magnetic domains are 1 and 0

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http://www.spmtips.com/library-SPM-in-data-storage.lib

Next Gen: Spin Torque Transfer

• Spintronics: Integrated magnetic and electronic properties

• New materials, fab in conjunction with silicon elements

• Commercialized-> Everspin

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Bottom Up : 12 atom bit

• Antiferromagnetic bits• Needs 5K temps to operate 42

Magnetic Imaging

• MRI contrast agents• Magnetic Particle Imaging

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Goodwill, P. W., Saritas, E. U., Croft, L. R., Kim, T. N., Krishnan, K. M., Schaffer, D. V. and Conolly, S. M. (2012), X-Space MPI: Magnetic Nanoparticles for Safe Medical Imaging. Adv. Mater., 24: 3870–3877. doi: 10.1002/adma.201200221

Choi, J.-S. et al. A hybrid nanoparticle probe for dual-modality positron emission tomography and magnetic resonance imaging. Angew. Chem. Int. Ed. 47, 6259–6262 (2008)