One-step synthesis of Au-coated porous silicon as a surface enhanced Raman scattering substrate for biomolecule detection

Porous silicon (pSi) coated with gold (Au) was synthesized by a one-step electrochemical etching process without any post treatment. The porous nature was confirmed by scanning electron microscopy (SEM) as well as Raman and photoluminescence spectroscopy. The surface enhanced Raman spectroscopic (SERS) sensing performance of Au-coated pSi (Au-pSi) was compared with uncoated pSi by using rhodamine 6G dye as the analyte. The bio-sensing performance of Au-pSi was evaluated using bovine serum albumin (BSA) protein as the analyte. The Au-pSi shown better sensitivity for R6G and BSA as compared to pSi.