Controlling surface enhanced Raman scattering using grating-type patterned nanoporous gold substrates

We investigate the effect of grating design on surface enhanced Raman scattering (SERS) intensity using patterned nanoporous gold (P-NPG) films. The SERS response is systematically engineered by tuning the parameters of gratings imprinted on the nanoporous gold films, including grating period, duty cycle, and height. Compared to conventional NPG films, where the localized surface plasmon dominates the strong SERS response, the significantly enhanced SERS response from our P-NPG structures primarily arises from efficient activation of a surface plasmon polariton and its coupling with the localized surface plasmon mode. The P-NPG SERS substrates exhibit large area uniform enhancement factors near 108.