Fabrication of Ag/ZnO/reduced graphene oxide nanocomposite for SERS detection and multiway killing of bacteria

Ag/ZnO/reduced graphene oxide (Ag/ZnO/rGO) nanocomposite was developed for the detection and multiway killing of bacteria. It combined the photocatalytic property of ZnO nanoparticles, the high specific surface area and near infrared (NIR) photothermal conversion property of rGO, as well as the bacteria-killing capability and surface enhanced Raman scattering (SERS) property of Ag nanoparticles. Firstly, ZnO/rGO nanocomposite was prepared by solvothermal method with zinc acetate and graphene oxide (GO) as the precursors. The influences of GO content on the growth of ZnO nanoparticles onto the surface of rGO and the photocatalytic property were examined to obtain a ZnO/rGO nanocomposite with better photocatalytic activity. Secondly, Ag nanoparticles were further deposited on the surface of ZnO/rGO nanocomposite by the microwave-assisted arginine reduction method. It was demonstrated that the resulting Ag/ZnO/rGO nanocomposite could be used for both the SERS detection and efficient killing of E. coli. Furthermore, it was shown that the bacteria-killing performance of nano-Ag could be effectively enhanced by combining the photocatalytic or photothermal mechanism.