IM-SURE Fellow: Georges SiddiqiDepartment of Chemical Engineering University of California, Los Angeles

Mentor: Professor Regina RaganPost-Doctoral Researcher: Dr. Ju H. ChoiDepartment of Chemical Engineering and Materials ScienceUniversity of California, Irvine

Study of Self Assembled Nanoparticle Arrays on

Diblock Copolymer Templates

Outline

•Our motivations•Introduction to concepts•Project goals•Experimental outline•Results and discussion

Motivation

• Create biosensors that are both• Cost effective• Highly sensitive

• Existing biosensors are large, mechanically complicated and expensive

•Difficult, time consuming and expensive to detect many biological molecules

Introduction

•Use plasmon resonance spectroscopy to create highly sensitive biosensors

Van Duyne R.P. et al, Nano Lett., Vol. 4, No. 6, 2004

•Diblock copolymers form two distinct phases depending on fraction of each

•Using poly(styrene-b-methyl methacrylate) (PS-b-PMMA)

Introduction

Introduction

•Combine diblock copolymer templates with nanoparticles

PMMA PMMAPS

Creates cost effective templates

•Combine nanoparticle arrays with plasmon resonance spectroscopy

Creates highly sensitive biosensor

PMMA

Polymersubstrate

Project Goals

•Three goals for this project:•Create size-controlled nanoparticles•Create diblock copolymer•Attach nanoparticles

Monolayer protected Au/Ag nanoparticle synthesis

Diblock-copolymer templates (PS-b-PMMA)

(What I did)

•Convert –COOCH3 group to carboxylic acid

Experimental Outline

•React with EDC and Sulfo-NHS to form amine reactive ester•Attach functionalized nanoparticle

Results

•Initial Results

Results

•Complications with morphology

Results

Spin speed &Conc. of PS-b-PMMA

3000 rpm 4000 rpm 5000 rpm

1 wt% 55nm(70%)

50nm (60%)

49nm (64%)

2 wt% 88nm(92%)

88nm(87%)

85nm(75%)

•Control of film thickness

Results

•Problems with template damage and their solutions

Results

•Problems with nanoparticle aggregation

Results

•Controlling nanoparticle size

Expected NP size ~10nm Expected NP size ~20nm

Results

•Finally some good stuff

Acknowledgements

•Professor Regina Ragan•Dr. Ju H. Choi•Jere. A Wilson for some bangin’ NPs•UCI IM-SURE Program•NSF REU Program•Carl Zeiss Center of Excellence