SERS-active substrates based on metallic nanocracks on PDMS

We present a novel type of surface enhanced Raman scattering (SERS)-active substrates based on nanoscale metallic cracks formed on the surface of polydimethylsiloxane (PDMS). Compared with Raman spectral signals of Rhodamine B (RB) solutions on flat metal/PDMS surfaces without the nanocracks, the nanocrack regions on this SERS-active substrates have an enhancement factor on the order of 4 ?? 106. Moreover, with photolithography and 'lift-off' techniques, metals might be patterned on the PDMS layer; and by bending the PDMS layer along certain directions, SERS-active substrates based on patterned metallic nanocracks are achievable. Such SERS-active substrates may be integrated into micro-fluidic systems for further wide range of applications. ? 2011 IEEE.EI