Nanoreplicated positive and inverted submicrometer polymer pyramid array for surface-enhanced Raman spectroscopy

We demonstrated gold-coated polymer surface enhanced Raman scattering (SERS) substrates with a pair of complementary structures-positive and inverted pyramid array structures fabricated by amultiple-stepmolding and replication process. The uniform SERS enhancement factors over the entire device surface were measured as 7.2x10(4) for positive pyramid substrates while 1.6x10(6) for inverted pyramid substrates with Rhodamine 6G as the target analyte. Based on the optical reflection measurement and finite difference time domain simulation result, the enhancement factor difference is attributable to plasmon resonance matching and to SERS hot spots distribution. With this simple, fast, and versatile complementary molding process, we can produce polymer SERS substrates with extremely low cost, high throughput, and high repeatability. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3663259]