Au-Coated PDMS grating for SERS substrate: Comparison of two different grating depths

Surface enhanced Raman scattering substrate was an alternative analytical tool with ultrahigh sensitivity and rapid response for chemistry, medicine and forensics science. In this work, the surface enhanced Raman scattering (SERS) substrate based on PDMS grating structure created by laser interference lithography using excimer laser modification and further 80 nm-thick Au thin film deposition by dc magnetron sputtering was proposed. We investigated the effect of the grating depth on SERS performance. The methylene blue solution of different concentration was employed to test the SERS performance using the portable Raman spectrometer. The optimal SERS performance can be optimized by fabricating the PDMS grating structure with 850 nm-period, 310 nm-depth and 0.5-filling factor.