▎ 摘　　要

Graphene-Fe3O4 (G-Fe3O4 ) nanocomposites with different GO/Fe3O4 weight ratios of 1-1, 1-3 and 1-5 were synthesized using solvothermal method. Also, Fe3O4 nanoparticles (NPs) were separately synthesized by the same method. The prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. Zeta potential analysis and scanning electron microscopy (SEM) were employed to measure the surface charge and the destruction processes of the bacteria. The XRD analysis showed that the graphene oxide had been reduced and also confirmed the formation of G-Fe3O4 nanocomposites. The antibacterial properties of the prepared samples were investigated against Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) strains, using three different methods. Our results revealed that the G-Fe3O4 with 1 -5 wt ratio has higher antibacterial activity and lower toxicity, compared to the other two nanocomposite samples, GO and also Fe3O4 NPs. (C) 2018 Elsevier B.V. All rights reserved.