Reusable SERS active substrates for ultrasensitive molecular detection

Abstract

Silver nanoparticles coated silicon nanospikes were investigated as efficient and reusable SERS active substrates. Silicon nanospikes were fabricated employing femtosecond laser pulses and were made SERS active through deposition of silver nanoparticles by reducing silver nitrate. The prepared substrates offer good SERS reproducibility with high enhancement factors. The SERS detection limits of 1 pico-molar from Rhodamine 6G and 100 pico-molar from Methylene blue were demonstrated. In addition, these SERS substrates are reusable by simple washing and no observable degradation of sensitivity was measured.