Porous silicon photonic crystal/silver composite produced by microwave-assisted reduction: Applications to surface-enhanced Raman scattering

Abstract

A high enhancement activity is realized via reduction of silver nanoparticles on multilayered porous silicon assisted by microwave radiation. The as-prepared silver nanoparticles/porous silicon photonic crystals (Ag NPs/PSi PhCs) surface enhanced Raman scattering (SERS) active substrate shows outstanding performance in detecting Rhodamine 6G (R6G). A maximum enhancement factor (EF) of 7.8 × 1014 for R6G and a 9.38% relative standard deviation (RSD) of repeatability at a R6G concentration of 10−12 M are obtained, confirming the high sensitivity and excellent uniformity. The strong SERS activity is ascribed to the advantages of photonic crystal effect of PSi PhC and microwave radiation in regulating absorption and distribution of Ag NPs on PSi PhC, which results in a high density of hot spot regions to improve the SERS signals. In general, the Ag NPs/PSi PhCs SERS active substrates exhibit great potential applications the fields of environment, food and disease diagnosis.