In Situ Synthesis of Silver Nanospheres, Nanocubes, and Nanowires over Boron-Doped Graphene Sheets for Surface-Enhanced Raman Scattering Application and Enzyme-Free Detection of Hydrogen Peroxide.

An effective in situ synthesis strategy is demonstrated for the preparation of silver nanostructures (nanospheres (NSs), nanocubes (NCs), and nanowires (NWs)) on the surface of boron-doped graphene (BG). Further, these functional nanomaterials are employed for the surface-enhanced Raman scattering (SERS) and non-enzymatic electrochemical detection of H2O2. The results confirm the superior performance of BG-Ag nanostructures as SERS platform. Among various geometries of silver nanoparticles studied in this work, we find that the AgNCs over BG (BG-AgNC) present outstanding SERS performance for detecting 4-mercaptobenzoic acid, with a limit of detection of 1.0 × 10-13 M. Furthermore, BG-AgNC exhibits excellent capability to detect melamine as low as 1.0 × 10-9 M. Electrochemical results confirm that the BG-AgNW-based platform exhibits a superior biosensing performance toward H2O2 detection. The enhanced performance is due to the presence of graphene, which improves the conductivity and provides more active sites. The synthesis of doped graphene with metallic nanoparticles described in this work is expected to be a key strategy for the development of an efficient SERS and electrochemical sensor that offers simplicity, cost-effectiveness, long-term stability, and better reproducibility.