Anti-microbial activity of cobalt doped zinc oxide nanoparticles: Targeting water borne bacteria

Zinc oxide (ZnO) nanoparticles were chemically synthesized with cobalt doping and characterized through UV–visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques. Cobalt doped ZnO nanoparticles were found to be crystalline having a single phase as confirmed by XRD and SEM. It has been observed that the increase in the percentage of Co from 0% to 5% in ZnO, increases the crystallite size from 20.5 to 25.7 nm and accordingly its band gap varies from 3.22 to 3.30 eV. After treatment morphology of materials was changed from rod to spherical shaped. Further these nanomaterials were applied as a bactericidal agent to control water borne bacterial pathogen. Cobalt doping on zinc oxide and exposure of sunlight enhanced the antibacterial activity against water borne bacterial isolate at 50 μg concentration. Interestingly, most effective bactericidal results were found against Escherichia coli and Vibrio cholerae.