Novel route for the preparation of cobalt oxide nanoparticles/reduced graphene oxide nanocomposites and their antibacterial activities

In this work, we report a simple one step microwave irradiation method for the synthesis of cobalt oxide (Co3O4) nanoparticles and their reduced graphene oxide (RGO) based nanocomposites as an antibacterial agent against microorganism. X-ray diffraction (XRD), and Raman studies revealed the formation of crystalline Co3O4 nanoparticles supported onto the RGO sheets. Ultraviolet–visible (UV–vis) spectra showed the characteristic absorption peaks of Co3O4 nanoparticles and RGO. From field emission scanning electron microscopy (FESEM) analysis, nanoporous structure was observed for Co3O4/RGO nanocomposites. Antibacterial activity of these nanocomposites against gram-negative bacterium Escherichia coli (E. coli) was carried out. It was observed that Co3O4 nanoparticles supported on RGO sheets showed antibacterial activity against E. coli in contrast to the GO, RGO sheets and Co3O4 nanoparticles itself which did not show any antibacterial activity against E. coli. The presented approach to prepare graphene based nanocomposites within few minutes using the cheap, cost effective and environmental friendly microwave irradiation method will be a track to bridging between laboratory and industry for future biomedical applications.