Synthesis, characterization and a comparative antibacterial study of CuO, NiO and CuO-NiO mixed metal oxide

Abstract

Infections caused by bacteria and microbes are a serious threat to human health. Metal oxides have exhibited significant antibacterial activity which has resulted in apoptosis of bacterial strains. In this work, pure metal oxide nanoparticles along with bimetallic mixed metal oxide nanoparticles were synthesized and were also characterized using X-ray powder Diffraction (XRD) analysis, Field Emission Scanning Electron Microscope (FESEM) analysis, Transmission Electron Microscopy (TEM) analysis, Fourier Transform-Infrared Spectroscopy (FTIR) and UV-Visible Absorption Spectroscopy. Also, the antibacterial activity tests were carried out for these nanoparticles. The toxicity of the nanoparticle was assessed using gram positive bacteria (Staphylococcus aureus) and gram negative bacteria (Escherichia coli). A preliminary assessment of antibacterial activity of pure metal oxide and mixed metal oxide was carried out which includes growth kinetics study, inhibition rate study and cell integrity study. A comparative study of these preliminary assessments was carried out between the mono-metallic oxide nanoparticles (i.e., CuO and NiO) and bimetallic mixed metal oxide CuO-NiO nanoparticles in order to understand the synergistic interaction of copper and nickel metals. It was seen that CuO-NiO nanoparticles and CuO nanoparticles were more toxic to S. aureus than E. coli and vice versa for NiO nanoparticles alone.