Facile fabrication of silver nanoparticles on silicon for surface‐enhanced infrared and Raman analysis

A facile and economic method to fabricate and immobilize silver nanoparticles on a thin Si wafer (AgNP/Si) is reported for an analytical template in ambient environment by surface‐enhanced infrared/Raman spectroscopy. The protocol involves immersion of the Si wafer in a solution containing silver nitrate and hydrofluoric acid. To screen appropriate conditions for preparing AgNP/Si for SEIRAS application, different combinations of AgNO 3 and HF solutions were examined with paranitrobenzoic acid (PNBA) used as the probe molecule in transmission measurements. These SEIRA‐active substrates were also promising for SERS application, as demonstrated with high quality SERS spectra of iron (III) protoporphyrin adlayer on AgNP/Si with a red excitation line. The AgNP/Si substrates prepared under different conditions were examined by SEM for qualitative correlation of enhancements with morphologies.