Reduced graphene oxide and ZnO decorated graphene for biomedical applications

The ability of graphene-based materials to enhance the conventional antibiotic resistance is well known and researchers have been interested in improving their antibacterial activity. The reduction of graphene oxide by eco-friendly reducing agents is of great interest on the basis of environmental and human health aspects. Herein we report the synthesis of two forms of graphene derivatives namely, reduced graphene oxide (RGO) through reduction using potato starch and zinc oxide decorated RGO (ZnO-RGO). In the case of ZnO-RGO, the reduction of graphene oxide and the conversion of ZnO to nano ZnO occur simultaneously. The characterization of all the graphene based materials and nanocomposites developed were carried out using FT-IR, XRD, Raman spectra and TEM techniques. The antibacterial activity of these modified materials against E. coli was also studied by well diffusion method. Our results show that ZnO-RGO is more efficient than RGO in their antibacterial properties which we attribute to the synergistic effect of ZnO and RGO towards the bacteria in the nanocomposite. Further we find that the antibacterial effect of ZnO-RGO towards E. coli is due to the disruption of the bacterial cell which could be confirmed by AFM images. Considering the fact that graphene-based materials are less toxic towards mammalian cells, both RGO and ZnO-RGO we have developed can find applications in the field of medicine and life sciences.