Large-scale solvothermal synthesis of Ag nanocubes with high SERS activity

A novel solvothermal method has been developed to synthesize Ag nanocubes with controllable size. The PVP was used as the capping agent, ethylene glycol as reducing agent and glycerol as the viscosity regulator in the growth of Ag nanocubes. The high pressure generated from solvothermal condition favors the etching of Ag twin seeds and the formation of Ag single crystal seeds. Ag nanocubes with size ranging from 50 to 120 nm have been realized. The influence of glycerol, NaCl and PVP concentration, reaction temperature and time on the size and morphology of Ag nanocubes were analyzed and discussed. The Ag nanocubes have been found to be a high SERS-active substrate, and the detecting limit of thiram can reach as low as 10−9 M.