Antibacterial and antioxidant screening applications of reduced-graphene oxide modified ternary SnO2-NiO-CuO nanocomposites

Generally, Graphene oxide (GO) was fabricated by modified Hummer’s method and was thermally reduced whereas the tri-metallic nanocomposite was prepared by ex-situ hybridization. Both the synthesized SnO2-NiO-CuO (SNC) and rGO-SnO2-NiO-CuO (GO-SNC) were calcined at 450 °C for 2 h. The degree of crystallinity and the crystallite size were examined through X-ray Diffraction (XRD) analysis and were found to increase with calcination temperature. The morphological changes were examined through scanning electron microscopy (SEM). The surface functional moieties were identified through Fourier transform infrared (FTIR) spectroscopy. Agar well diffusion method was used to evaluate samples against Gram-negative bacteria (E. coli) and Gram-positive bacteria (S. aureus). The antioxidant potential was analyzed against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radicals and the highest activity was found for the as-synthesized NC whereas a clear decrease was seen in both activities with after calcination at 450 °C. It was also observed that the antibacterial and antioxidant activities increased with increasing sample dose in the reaction.