A room temperature dry reduction approach, i.e., a low pressure dielectric barrier discharge (DBD) plasma jet, was presented to synthesize highly dispersed graphene oxide-based Ag nanoparticles. TEM, EDS, XRD and XPS tests were used for the characterization of the as-prepared nanocomposites. By comparing the Ag nanoparticles prepared by the DBD plasma jet with and without hydrogen plasma pretreatment, it was found that the latter were highly monodispersed with a uniform size of around 2 nm and deposited on the surface of the graphene oxide as a form of face-centered cubic structure, and it also showed a better antibacterial activity against Escherichia coli, which may be due to the smaller particle size, larger surface area and more beneficial dispersity of Ag nanoparticles. (C) 2014 Elsevier Ltd. All rights reserved.