““Lighting the Way to Lighting the Way to NanoNano--Technology through InnovationTechnology through Innovation””

P.N.Prasad

NanomaterialsNanomaterials Based Nanotechnology toBased Nanotechnology toMeet the 21Meet the 21stst Century Technical ChallengesCentury Technical Challenges

The Institute for Lasers, Photonics and Biophotonics The Institute for Lasers, Photonics and Biophotonics www.photonics.buffalo.edu

Global Government Funding in 2008:

7.849 B$

US: 1.821 B$

China: 0.510 B$

Russia: 1.076 B$ EU: 2.440 B$

India: 0.050 B$

Korea: 0.350 B$ Japan: 1.128 B$

http://www.cientifica.eu/images/Whitepapers/nor-sample.pdf

Restof World:0.510 B$

NANOTECHNOLOGY: A GLOBAL PRIORITY

The Institute for Lasers, Photonics and BiophotonicsMultidisciplinary Frontier Research in Lasers, Photonics and Biophotonics

Extensive Research Facility ($26 million)

Education and Training Funded by NSF

Industrial Collaboration : Co-development, Industrial training, advanced testing

Technology Transfer : 5 spin off companies (Laser Photonics Technology, ACIS, Hybrid Technologies, NanoBiotix and Solexant Inc.)

International collaboration : Joint research, Student exchange, Joint workshop

The Institute for Lasers, Photonics and Biophotonics The Institute for Lasers, Photonics and Biophotonics www.photonics.buffalo.edu

3-D Bar Code

SOLEXANT CORPORATION

Subject of Global Priorities Subject of Global Priorities

Energy

Health Care

ChemicalAnd

BiodefenseEnvironment

Information Technology

NANOMATERIALSDendrimers

Prasad & Frechet

DURINT

eehν Block Copolymer Morphologies

Thomas, M.I.T.

Block-copolymers

Bates

Supramolecular

assembly

Self-assembly of dendrons

Percec

3 nm 7 nm3 nm 7 nm

Nanoparticles: QDs

Prasad

np no

ne

~ 200 nm

~ 10 nm

Nanocomposites

Prasad

Liquid Crystal nanodroplets

QDsPolymer

Prasad & Suga

Bridger-DNA

2D periodic arrays

Lineararrays

DNAduplex

Continuedarrays

Continuedarrays

=

O

O

O

O

NN

O

OO

O

O

O

HN

NH

DNA-NH2

DURNT KickDURNT Kick--Off Meeting at UB, Nov. 3rd 2001Off Meeting at UB, Nov. 3rd 2001Self-assembly on DNA template

Self-assembly

Fuel CellsSolar Energy

NanotechnologyNanotechnologyforfor

EnergyEnergy

Oil & Gas

Bio-fuelsHydrogen

Fuel

ThermoelectricPower

Solid StateBatteries

Nanotechnology for Solar Energy ConversionOur objective:

Hybrid nanomaterials‐based next generation flexible 

solar cells for broad band solar harvesting

Buffalo TeamProfessor P. N. PrasadProfessor A.N. CartwrightProfessor D. WatsonDr. H.S. OhDr. J. SeoDr. S.J. KimDr. P. RodriguesMr. W.J. KimMr. D.H. Lee

International CollaborationProfessor K.S. Lee, KoreaProfessor D.H. Choi, KoreaProfessor L. Akcelrud, BrazilProfessor J. Dutta, ThailandProfessor A. Ho, Hong KongProfessor, A. Gomes, Brazil

Nanotechnology for Efficient Harvesting of Solar EnergyNanotechnology for Efficient Harvesting of Solar Energy

Current technologies need improvement in:• IR conversion• UV conversion

Carrier multiplicationby UV absorption in quantum dots

Bi-exciton

Hot Exciton

ħωc

2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Nor

mal

ized

Car

rier E

xtra

ctio

n

[Ele

ctro

ns/ P

hoto

ns]

Photon Energy/Eg

Sample #0510073_3Absorption Peak: 1670nmApplied Bias: 3V

S.J. Kim, P.N.Prasad et al, Appl. Phys. Lett. 92, 031107 (2008)

Nanophotonics

solution:3 nm 7 nm3 nm 7 nm

QD with tunable absorption

Photon Harvestingby IR absorbing QDs

Facilitated Charge separationBy conjugation to SWNT

Enhanced charge collection by high mobility organics

Quantum dotsfor harvestingIR photons

Cho, Prasad et al.,Adv. Mater. 19, 232 (2007)

Nanotechnology for UV Light HarvestingChallenges:

Extracting charge generated by MEGShort (ps) exciton lifetime vs. long (ns) charge transfer

timeSurface recombination by traps and defects on QDsControlling phonon dynamics and charge transferUV transparency of matrix for Quantum Dots (QDs)

Our Approaches:

Lateral patterning of QDs for perpendicular junction formation using t-BOC ligandsSurface modification to minimize defects and trapsFundamental investigation of charge transfer dynamics between QDs and other materials using spectroscopic studyLigand exchange to reduce charge transfer barriersIncorporation of Transparent Conducting Oxides

τET

= 0.84 μs

electroelectro

dede

λ

= 1.34 μm

++++ N)(

glassglassITOITO

pentacene PbSe

QD PVK

Example of IR Example of IR PhotodetectionPhotodetection Enhancement :Enhancement :Case of Case of PentacenePentacene as a coas a co--constituentconstituent

•• Soluble precursor to pentacene

• Dramatic enhancement of photoconductive efficiencyFrom 3% to 8%

Max EQE ~ 8% Max EQE ~ 8% in the IRin the IR

Choudhury, et al., Appl. Phys. Lett. 89, 051109 (2006).

Infrared Sensitization for PhotovoltaicsChallenges

:

Photon harvesting in IR: Small absorption coefficient Need for a compatible low bandgap polymer matrixDevice Optimization: Low bandgap Low VocCreating environmentally friendly nanocrystals to

replace PbSe and PbSPhoto-enhanced oxidation of QDs: Short cell lifetime

Our Approaches

:

Plasmonic enhancement using metallic nanostructures and binary metal:semiconductor nanostructures

increase absorption Low bandgap polymers for better band alignment to QD

bandgapOptical Tuning of QDs combined with multi-junction solar

cell structuresNew “Green” IR absorbers (e.g., Cu2S)Oxygen free processing combined with encapsulation

PbSe

QDs

400 500 600 700 800 900 1000 1100 1200 1300

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Abs

orba

nce

(a.u

.)

Wavelength (nm)

New IR absorbing nanoparticles

Optical and electrochemical properties of PCPDTBT

NSN

Br BrSS

NSN

n

PCPDTBT(Blue solid)

SS

+

Bu3Sn SnBu3

Polymerization(Stille coupling)

400 500 600 700 800 900

0.0

0.1

0.2

0.3

Abs

orba

nce

Wavelength (nm)

PCPDTBT film

Molecular weight Abs. max. HOMO LUMO Band gap

Mn = 26 kDaMw = 50 kDa

720 nm (film) -4.96 eV -3.60 eV

1.36 eV (EC)1.53 eV (OP)

NIR absorption

Development of efficient NIR polymer;Synthesis of the low-band gap polymer (PCPDTBT)

We can modify the polymer structures to obtain various polymer structures with tunable band gap(700-1000 nm)

NX

N

NY

N

RmSS n

R = Aromatic group (m=1,2) X = Y = S or Se

PCPDTBT:PCBM

ITOPEDOT

LiF/Al

500 600 700 800 9000.0

0.1

0.2

0.3

0.4

0.0

0.1

0.2

0.3

0.4

Absorbance

Spe

ctra

l res

pons

ivity

(A/W

)

Wavelength (nm)

PCPDTBT:PCBM (1:3.6)

Photovoltaic performance (preliminary result)

-0.2 0.0 0.2 0.4 0.6 0.8-10

-8

-6

-4

-2

0

2

4

Cur

rent

den

sity

(mA

/cm

2 )

Voltage (V)

AM 1.5G AM 1.5G through 715 nm long pass filter

Voc Jsc FF PCE

AM1.5G

0.65 8.17 0.37 1.96

Filter 0.62 2.69 0.40 0.68

NIR contribution: ~34.6%

CdSe multipod CdTe QD PbSe QD CdSe QD

Photo-patternable

Nanocrystal

Quantum Dots and Multipods

Current-voltage curves (a) at r.t. for an array of CdTe

NCs

in the dark and during excitation with white light. MSM device structure (b) for photoconductivity measurement.

Typical structure  and components of DSSC

1. Absorption

2. Electron Injection

3. Regeneration

‐

Reaction at Cathode

Reactions at Anode

4. Re‐reduction of electron donor

Dye Sensitized Solar Cells (DSSC)

Operation Cycle

Counter Electrode

TCO Coating (FTO)

Pt

Glass

Glass

Electrolyte

Transparent Conducting Oxide Coating (FTO)

Photo-Electrode

Courtesy J. Dutta

Technical Challenges1.

Light Harvesting by QDSSCs2.

Electron injection between QDs

and the metal oxide substrate; hole injection from electrolytes (or hole transporting layers) to QDs.

3.

Charge-collection efficiencies of QDSSCs

and the problem of bulk electron transfer processes.

4.

Photostablity

and Longevity of QDSSC.

Our Strategy1.

High surface loading of QDs; near IR absorbing nanocrystals; plasmonic

enhancement of photoexcitation.

2.

Optimize interfacial charge transfer by surface functionalization

and better interconnectvity.

3.

Improve electron transport by using nanowires and hole transport

by using medium with high hole mobility.

4.

Surface functionalization

and protective coating.

Quantum Dot Sensitized Solar Cell Challenges

0.0 2.0x10-6 4.0x10-6 6.0x10-6 8.0x10-6

-0.020

-0.015

-0.010

-0.005

0.000

Abs

orba

nce

chan

ge

Time (s)

CdS-S-(CH2)15-CO2-TiO2 CdS-S-(CH2)5-CO2-TiO2 CdS-S-(CH2)2-TiO2

Distance‐dependent electron injection

Optimizing Charge Transfer in Composite SystemsMaterials assembly: modification of ligands

CdS(e)

TiO2R

O

OH + TiO2RO

O TiO2S R

O

OCdS(e)

AHSHSHO

H2O

B

Electron injection

hν

Dibbell, R.S.; Soja, G.R.; Hoth, R.M.; Watson, D.F. Langmuir 2007, 23, 3432-3439 Mann, J.R.; Watson, D.F. Langmuir 2007, 23, 10924-10928

400 500 600 700 800

-0.020

-0.015

-0.010

-0.005

0.000

Abs

orba

nce

chan

ge

Wavelength (nm)

CdS CdS-S-(CH2)2-CO2H CdS-S-(CH2)2-CH3 + TiO2 CdS-S-(CH2)2-CO2-TiO2

λpump

= 415 nm (6-8 ns)τdelay

= 160 ns1:1 THF:EtOH

Nanosecond transient absorption spectra

Dibbell, R.S.; Watson, D.F. J. Phys. Chem. C 2009, 113, 3139-3149

Nano‐wire

CB

VB

Eg

ee

CdSQD

Cu2

SQD

Direct and Fast transport electron in DSSC by using Nanowires

hν

Bandgap

Alignment 

for Carrier Cascade 

QD‐sensitized nanowires: directional charge transport

Collaboration: Prof. J. Dutta

(Thailand), Prof. A. Ho (Hong Kong), Prof. A. Gomes (Brazil)

400 450 500 550 600 650

0.0

0.5

1.0

1.5

Abs

orba

nce

Wavelength (nm)

Novelty:•

Heterolayers

of QDs

via in situ

precipitation or

surfactant‐mediated 

self‐assemblyObjectives:•

Enhanced light‐harvesting efficiency 

(LHE)•

Cascading interfacial electron transfer

Heterolayer

QD‐sensitized solar cells

CdS‐TiO2

: optimizing fabrication, LHE 400 450 500 550 600 6500.0

0.5

1.0

1.5

Abs

orba

nce

Wavelength (nm)

TiO2 TiO2-CdS(6) TiO2-CdS(6)-CdSe(4)

In situ

precipitation

Heterolayer

QD‐sensitized solar cells

0.0 0.1 0.2 0.3 0.4 0.5 0.6-8

-6

-4

-2

0

Cur

rent

den

sity

(mA

cm

-2)

Voltage (V)

TiO2 TiO2-CdS(6) TiO2-CdS(6)-CdSe(4)

Jsc

= ‐6.4 mA

cm ‐2

Voc = 0.522 VFF = 0.41PCE = 1.4%

Removal of CO2

from Natural Gas

High porous matrix(proprietary materials)

Nanoparticle coated porous matrix

Dip c

oatin

g

CO2

storage platform

CO2

Nanoparticle CO2

scavenger(proprietary chemistry)

CO2

A Commercial Opportunity

Cancer

Aging Obesity

Addictions

InfectiousDiseases

Genetic Disorders

Current and Future Health Care Challenges

Health and Wellness through Life Span to Increase the “Quality of Life”

Disease PreventionEarly detection of disease Effective therapy (personalized)Post therapy/surgical assessmentCapacity to monitor therapeutic efficacy

Nanotechnology solution:NANOMEDICINE

Tailoring of Nanoparticle Platform

• Chemical “make-up” (inorganic; organic; hybrid)Single or multimodal imaging

• Shape (dots; rods; multipods)Spectral characteristics (controlled excitation/ emission)

• Size (1- 100 nm)Spectral characteristics, circulation control, biodistribution

• Porosity controlLoading/release of payloads

• Surface charge (positive, negative, neutral)Targeting agent coupling site, payload stability

• Surface characteristics (hydrophilic; hydrophobic)circulation control; payload stability

• Surface coating (organic; protein; nucleic acid)Biotargeting; circulation control; biodistribution; payload stability, controlled release

Nanotechnology-

based In Vitro Diagnostics

TORCH* Infections

Malaria

Influenza(Bird Flu)

Tuberculosis

HIV, HPV, Hepatitis B

Meningitis

*TORCH: Toxoplasmosis, Other agents (eg. Chicken pox, human parvovirus), Rubella, Cytomegaloviruse, Herpes simplex virus or HIV

Collaboration with Center for Disease Control, Atlanta

A Commercial

Opportunity

•

Semiconductor nanoparticles

with unique, tunable optical properties•

Highly photostable•

Narrow, symmetric emission spectra•

Ease of bioconjugation•

Ability for multiplexed analysis

Quantum Dots: New generation Diagnostic probes

lysine

Size tunable emission following illumination with UV Light

3 nm 7 nm3 nm 7 nm

Y

Y

Y

Y

Antibody forbiorecognition PEG for enhanced

colloidal stability

J. Qian, P.N.Prasad et al, J. Phys. Chem. B. 2007, 111 (25), 6969.

ApplicationsIn vitro ImagingIn-vitro DiagnosticsTargeted Drug deliveryTheranostics

InIn--VitroVitro Imaging Using Imaging Using NanoemittersNanoemitters

for Early Detection of Diseasesfor Early Detection of DiseasesUsing Cellular SignaturesUsing Cellular Signatures

Technical Challenges Our Approach

Optical TransparencyNear-IR emitting Nanoparticles

Surface Functionalization

for aqueous dispersions, while retaining high quantum yield

Core-Shell Structures, Surface functionalization

and coating

CdTe

ZnTe Cysteine

Reduction of Cellular Toxicity

Surface Functionalization

and Biocompatible Coating

Targeting group

PEG group

CdTe ZnTe

Process Control for Uniformity and Scalability, Green Chemistry

New Aqueous SynthesisCadmiumPrecursor

TelluriumPrecusor

Stabilizing ligand

↑100°C

In Vitro NIR Imaging using CdTe

QDs

In vivo

NIR-NIR optical bioimaging data: Ex = 975 nm, Em = 800 nm

In Vitro NIR Imaging using up‐conversion nanoparticles

Confocal microscopy 

image of live cancer cells 

treated with NIR QDs. 

Immunomicrobeads

captureanalytes

(soluble proteins)

Flow Flow CytometryCytometry: Rapid, multiplexed detection of trace amounts : Rapid, multiplexed detection of trace amounts of diseased cells/ protein biomarkers from biological samplesof diseased cells/ protein biomarkers from biological samples

(2) Lasers illuminate the dyes generating fluorescence

(1) Beads travel in a very narrow stream (thousands per sec) (4) Results are analyzed

(3) Multiple Signals are collected/detected/digitized

Microbeads

coated withcapture antibody

Bead A

Bead B

Bead C

QD-detection antibodieslabel the capture analytes

A Commercial

Opportunity

Technical challengesTechnical challengesEnhanced tissue penetration by light

Delivery across biological barriers (e.g. blood-brain barrier, liver, lung, etc.) andreduced nanotoxicity

and inflammatory response

Biodegradation and excretion of nanoparticles

Our strategiesOur strategies

Multimodal Imaging (e.g. PET, SPECT/CT, MRI and luminescence)

Reduction of hydrodynamic size of nanoparticles; modification of surface of nanoparticles

with long circulation “biocompatible”

polymer coating; conjugation of targeting biomolecules

to the nanoparticles.

Engineering biocompatible, stable, non-heavy metal based, and PEGylated

nanoparticles

(e.g. silicon).

Challenges and Solutions for In Vivo Nanotheranostics

Use of light in the biological window of optical transparency (~650 –

900 nm)

Molecular cellular morphological imaging and analysis

Near infrared phosphorescent polymeric nanomicelles: efficient optical probes for in vivo tumor imaging and detection

Biocompatible Silicon Quantum Dots as Biological Fluorescent Labels

Silicon nanoparticlesproduced by Laser-Driven

Pyrolysis

Process

Etching with

HF/HNO3

Etching with

HF/HNO3

Etching with

HF/HNO3

Hydrogen terminated

Silicon particles

Diff

eren

t co l

ors

of p

hoto

l um

ines

cenc

e

Erogbogbo, Prasad et al. ACS Nano

2008, 2(5), 873-876.

Si only

Si-RGD

Erogbogbo, Prasad et al. Under review in PNAS (USA). 2009

Tumor targeting with silicon NPs

ORMOSIL based multimodal nanoparticle platform

In-Vivo DiagnosticsMultimodal Nanoplatforms

for Medical Imaging

PET124I labeled-ORMOSIL

MRIGd-doped Nanophosphor

OpticalGd-doped Nanophosphor

M. Nyk, P.N.Prasad et al, Nano Letters, 2008, 8(11):3834; R. Kumar, P.N.Prasad et al. Avd. Func. Mater. (In Press, 2008)

SPECT/CT125I labeled-ORMOSIL

Nature Defense Mechanisms

Biological Barriers

SkinProtects against

environmental insult and microbial invasion

Mucosal barriersProtects surfaces against

environmental insults (chemical, bacterial and

particles)

Blood Brain BarrierProtects brain by

regulating the entrance of chemical and micro/nano

materials

Reticulo-Endothelial Barrier (RES)

Captures foreign materials for removal by liver and spleen

Time dependent liver clearance of PEGylated

ORMOSIL nanoparticles

Liver

AbdominalCavity

Day 0 Day 3 Day 7

Day 7(Dissected mouse)

Liver

Intestine

Stomach

Liver

Spleen

Dissected Mouse

Day 0 Day 7

Strategies for overcoming RES barrier

•

Encapsulating molecules within ultrafine nanoparticles

(diameter below 50 nm)

•

Modulation of surface charge of nanoparticles: Neutral or moderately negative surface charge favors RES escape

•

Coating nanoparticle surface with PEG or any other inert polymer

UPPER LAYERBLOOD END

DAY1 DAY2 DAY3 DAY4

DAY1 DAY2 DAY3 DAY4

LOWER LAYERBRAIN END

Gold nanorod

(GNR) –

fluorescent siRNA

Nanoplex:Optical tracking of time dependent transport across BBB

Confocal images showing enhanced staining of cells with time,thus indicating BBB transport

QR-RGD

QR only

In vivo diagnostics: Early detection of cancerTumor targeted delivery of RDG peptide conjugated QRs

following systemic injection

Tumor

Tumor

Yong, Prasad et al. Under review in ACS Applied Materials and Interfaces. 2009

PEGylatedPhospholipid molecule

Biodegradable PLGA molecule

Doxorubicin

Biodegradable Nanoparticles

in Imaging and Drug delivery

Cancer nanotechnologyTargeted delivery ●

Controlled release ●

Multimodal therapy ●

Real time monitoring

With Uttam

Sinha, M.D.Univ. of Southern California

Gene TherapyHead & Neck, Lung cancer

Gold NanorodGold Nanorod

With McMaster Univ.

Neutron capture therapyBrain, prostate cancer

NaYF4: Tm/GdNaYF4: Tm/Gd

With Anirban

Maitra, M.DJohns Hopkins Univ. Medicine

ChemotherapyPancreatic, Prostate cancer

lysine

YY

YYlysine

YY

YYlysinelysine

YY

YYlysine

YY

YYlysine

YY

YYlysinelysine

YY

YY

Magnetic therapy

US patent No. 6,514,481

Nanoclinic

Breast & Oral cancer

With Ravi K Pandey, Ph.D.Roswell Park Cancer Institute

PSPSSi

O

OO

I

SiO OI

ORMOSIL nanoparticle

SiO

OO I

PSPSSi

O

OO

I

SiO OI

ORMOSIL nanoparticle

SiO

OO I

Photodynamic therapyCervical, skin cancer

3 product familiesnanoTherapeutics30nm silica based Source Indication

nanoMag

nanoPDT

nanoXRay

• MRI

• Lasers

• X-Ray

Local treatment forsuperficial & cavity cancer

Local treatmentin the irradiation area

Local treatment and potentially whole body

A new dimension in cancer care

Paris, France http://www.nanobiotix.com/

Nanoplex

Gene delivery using nanoparticles

•Electrostatic gene condensation•Efficient cellular entry•Non-toxicity•High gene expression/silencing

Nucleus

Endosome

Protein

Nanoplex

Nucleus

Endosome

Protein

Nanoplex

Gene Augmentation e.g. CFTR gene in Cystic Fibrosis Gene Silencing e.g. Oncogene in Cancer

Nucleus

Endosome

Protein

Nanoplex

Nucleus

Endosome

Protein

Nanoplex

Nanoparticle mediated gene silencing: Implications in drug addiction therapy

Gene silencing efficiency of gold nanorod(GNR)-siRNA

nanoplex

is higher than that obtained using commercial agent (siPORT)

0

20

40

60

80

100

siPROT-neg control siRNA(200pM)

GNR 640-DARPP-32 siRNA(200pM)

siPROT-positive controlDARPP-32 siRNA (200pM)

% C

hang

e in

DA

RPP

-32

expr

essi

on

A.C. Bonoiu, P.N. Prasad, et al. Submitted to Proceedings of The National Academy of Sciences of USA, (2008) Collaboration with Stanley M Schwartz, M.D., Buffalo General Hospital

Slow Release of active principles

For Maximizing Efficacy

Nanofibers

for ImprovedTopical Formulations

Nanotechnology for Cosmetics Nanocosmetics

*

*US nanocosmetic

market in 2001 19 $B was extended at 58 $B in 2008

Deep Skin Penetration of

Anti-aging nanocosmetics

Nano-stabilized Botanicals Enabling

New Class of Cosmaceuticals

Nanoencapsulated

ScentsFor Long Lasting perfume

NanotechnologyFor

Information

Communication:

•

Reconfigurable Photonic

Crystals

•

3D Plasmonic

Guiding and Routing

Network

Displays(Organic Displays:

OLED, PLED)Storage:•

3D Two-Photon Storage•

Holographic Storage

Processing:•

Electro-optic Processing Using Supramolecular

Structures

and Nanocomposites

•

Electrically and Optically Switchable

Photonic Crystals

Nanotechnologyfor

Environment

Rapid in-field and remotemonitoring

Nanoporous

membranetechnology for

decontaminationand purification

Nanoparticle basedcapture platform

Nanostructured

sensorand device platforms

Nanotechnologyfor

Chem/Bio Defense

Rapid in-field and remote detection

Nanomedicine

based

rapid medical responseNanostructured

capture anddetoxification platform

Rapid disseminationof information

Nanostructuredsensor platforms

Fundamental and Technical Challenges for Nanotechnology

•

Fundamental Understanding of Physics at Nanoscale

(Electronic, Photonic, Magnetic)

•

New Physical and Chemical Processes

•

Manipulation of Excitation & Dynamics on Nanoscale

•

Control of Interfacial Interactions

•

Device Integration of Nanostructures

•

Nano-toxicity

NanotechnologyNanotechnology

• A new Multidisciplinary Scientific Research Frontier

• Ripe for Technological Innovation and Commercial Opportunities

• Destined to create Immense Societal Impact

Acknowledgements

Prof. A.CartwrightDr. K.TramposchDr. E.J. BergeyDr. G.S.HeDr. H. PudavarDr. K.T. YongDr. T. OhulchanskyyDr. I. RoyDr. S. KimMr. J. QianDr. H. DingDr. A. KachynskiDr. A. KuzminDr. A. PlissDr. A. BonoiuDr. D. BharaliDr. R.KumarDr. S. MahajanDr. J.W. SeoMr. S.J. KimMr. S.S. Kim

AFSOR (Dr. Charles Lee)National Cancer InstituteNational Science FoundationAFRL (Dr. Augustine Urbas)OISHEI FOUNDATION

Outside Collaborators

Prof. R. PandeyProf. A. OseroffProf. M. StachowiakProf. K.S. LeeProf. M. SamocProf. P. KnightDr. P. WallaceDr. A. MaitraDr. S. SchwartzDr. U. SinhaProf. J. DuttaProf. A. Ho Prof. A. Gomes

The Institute for Lasers, Photonics and Biophotonics The Institute for Lasers, Photonics and Biophotonics www.photonics.buffalo.edu

““Lighting the Way to Lighting the Way to NanoNano--Technology through InnovationTechnology through Innovation””

P.N.Prasad

NanomaterialsNanomaterials Based Nanotechnology toBased Nanotechnology toMeet the 21Meet the 21stst Century Technical ChallengesCentury Technical Challenges

The Institute for Lasers, Photonics and Biophotonics The Institute for Lasers, Photonics and Biophotonics www.photonics.buffalo.edu

•

Theory: multiscale

modeling (molecular, nanoscopic, bulk )

•

Synthesis and materials characterization•

Synthesis and surface functionalization

of nanoparticles•

Synthesis of functional organic monomers, oligomers, and polymers•

Assembly of nanoscopic

components into hybrid materials

•

Comprehensive characterization of relevant physical and chemical

processes•

Characterization of materials and surfaces•

Spectroscopy on multiple timescales•

Femtosecond-to-picosecond: electron injection dynamics•

Nanosecond-to-microsecond: electron injection yields, charge-

separated-state lifetimes

•

Device fabrication & characterization:

I-V measurements, short-circuit photocurrent action spectra

Nanotechnology for Solar Energy Conversion

Our capabilities:

A NEW APPROACH:Optical IR to visible up-conversion in RE nanoparticles

for solar cells

500 750 1000 1250 1500 1750 20000.0

0.2

0.4

0.6

0.8

1.0

1.2

[A.U

]

Wavelength [nm]

Solar Spectrum Polymer absorption

(P3HT/PCBM)

Reusable Energy by up-convertgin

Device Structure usingReflection Hologram

hν

hνhν’

Photovoltaic Cell

TPA Up‐Converting Layer

Reflection Hologram

Visible Abs. & IR Trans.

Up‐converting using IR

Reflection for IR & hν’

Upconverting

nanoparticle layer

980 nm

Excitation

Yb,Tm:NaYF4Yb,Er:NaYF4

ChloroformWater

50 nm

Up-converting nanoparticles

Engineering Fabrication and Integration of Nanostructures

A Commercial Opportunity

Photopatterning of Nanoparticles (Prasad, Propriety Technology)

Glass substrate Spin casting of NCs Photopatterning the film through a mask

UV

Develop the patterned filmUsing proper solvent

Photomask

NC

NC

Photopatterned

QDsGlass substrate Spin casting the NCs Photopatterning

the film Develop the patterned film

W.J. Kim, P.N. Prasad et al, Nano Lett., 2008, 8, p. 3262

UV

Photomask

100 μm 100 μm

Near IR

Up-conversion

Security Card

Security Application

Collagen

Gold nanorods/MMP’s

inhibitors

Collagen Type IIIBasal expression

Gold nanorods/siRNA

Castaneda L. et all.2008 Prasad et all. 2009 unpublished data

Gold nanoparticles/peptides

Personalized skin treatment with biocompatibile materials

Collagen Cross-Linking with Au Nanoparticles

Collagen Type IIIRecovered

Nanocosmetics present and future

•Skin Surface protection

• Skin surface penetrationRehydratation

/remodelation

•Skin treatment deep dermal/transdermal

deliver of therapeutic agents

The skin model ‘in vivo’In vitro skin model for testing

nanocosmetics

“Lighting the Way to Nano-Technology through Innovation”Slide Number 2Slide Number 3Slide Number 4Slide Number 5Slide Number 6Slide Number 7Nanotechnology for Efficient Harvesting of Solar EnergySlide Number 9Slide Number 10Slide Number 11Slide Number 12Slide Number 13Slide Number 14Slide Number 15Slide Number 16Slide Number 17Slide Number 18Slide Number 19Slide Number 20Slide Number 21Slide Number 22Slide Number 23Slide Number 24Slide Number 25Slide Number 26Slide Number 27Slide Number 28Slide Number 29Slide Number 30Slide Number 31Slide Number 32Slide Number 33Slide Number 34Slide Number 35Slide Number 36Slide Number 37Slide Number 38Slide Number 39Slide Number 40Slide Number 41Slide Number 42Nanoparticle mediated gene silencing:�Implications in drug addiction therapySlide Number 44Slide Number 45Slide Number 46Slide Number 47Slide Number 48Slide Number 49Slide Number 50Slide Number 51“Lighting the Way to Nano-Technology through Innovation”Slide Number 53Slide Number 54Slide Number 55Slide Number 56Slide Number 57