IM-SURE Fellow: Georges Siddiqi Department of Chemical Engineering University of California, Los Angeles Mentor: Professor Regina Ragan Post-Doctoral Researcher: Dr. Ju H. Choi Department of Chemical Engineering and Materials Science University 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

Combine diblock copolymer templates with nanoparticles PMMA PS Creates cost effective templates Combine nanoparticle arrays with plasmon resonance spectroscopy Creates highly sensitive biosensor

PMMA Polymer substrate 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 –COOCH 3 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 rpm4000 rpm5000 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 ~10nmExpected 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