Two different black silicon nanostructured surfaces modified with thin gold layers were tested for analytical signal enhancement with Surface-Enhanced Raman Spectroscopy (SERS). The relationship between the thicknesses of the gold layers and the analytical signal enhancement was studied. Also, effects of Ti and Ti/Pt adhesion layers underneath the gold layers on the analytical signal enhancement were tested. An enhancement factor of 7.6 x 10(7) with the excitation laser 785 nm was achieved for the tested analyte, Rhodamine 6G, and non-resonance SER spectra were recorded in a 5 s acquisition mode. Such an enhancement enables to achieve a detection limit down to 2.4 pg of Rhodamine 6G on a black silicon-based nanosurface coated with a 400-nm-thin layer of gold.
- Rhodamine 6G