This project addresses the utilization of Chemically Absorptive Nanopillars as a new, economical substrate to concentrate molecules and generate huge SERS enhancement. Experimental tests were conducted to demonstrate the absorptive property of the PDMS substrate, which concentrates target molecules around localized areas for enhanced SERS detection. Evidence of molecular concentration was demonstrated by monitoring the increasing fluorescence intensity of 1,2- bis(4-pyridyl) ethylene (BPE) as the molecules concentrate along the edge of an h-PDMS microfluidic channel. The SERS signal from our substrate was compared to the signal from substrates with less absorptive materials (glass), and demonstrated to have far superior performance. Our goal is to demonstrated that PDMS substrates can 1) collect more analyte by absorption, 2) demonstrate high SERS sensitivity for detection of analytes in femtomolar concentration, and 3) have reliable replication of identical structures, compared to conventional top-down or bottom-up fabrication techniques. This study will provide a simple, yet versatile SERS-substrate-integrated microfluidic platform.
Project end date: 02/03/11