Fabrication of graphene oxide/Ag hybrids and their surface-enhanced Raman scattering characteristics

A kind of surface-enhanced Raman scattering (SERS) substrate with high sensitivity was prepared via covalent assembly between silver nanoparticles (AgNPs) and graphene oxide (GO) sheets. With the high specific surface area, GO sheets can adsorb plenty of AgNPs; moreover, these adsorbed AgNPs formed some gathered state which can generate more hot spots of SERS. 4-Mercaptopyridine (4-MPY) was used to evaluate the SERS performance of the as-prepared substrate. The Raman enhancement factor (EF) of 4-MPY on the GO/AgNPs hybrids was up to 5.04×10(7), and the detection limit was estimated to be as low as 1 nM. The result showed that GO/AgNPs hybrids can produce stronger signals compared to silver colloids.