Thermal decomposition of metal complex precursor as route to the synthesis of Co3O4 nanoparticles: Antibacterial activity and mechanism

Current study was aimed to synthesize cobaltosic oxide nanoparticles (Co(3)o(4)NPs) through a novel synthetic route and investigate its antibacterial activity along with possible action mechanism against Escherichia coli (E.coli), a gram negative bacterium were investigated. The Co(3)O(4)NPs synthesized by onestep residue free in-situ thermal decomposition method and its structure and morphology were examined. Co3O4 NPs were found to be highly efficient in killing E. coli indicating about 99% reduction in cell growth. The cell wall deterioration was directly evidenced by field emission scanning electron microscopy. The potent antibacterial activity of Co3O4 NPs were found to be due to the electrostatic attraction between bacterial cell wall and Co(3)O(4)NPs and further reactive oxygen species production by Co3O4 NPs which in turn leads to intracellular oxidative stress as manifested by zeta potential, electron spin resonance and dichlorofluorofluorescein-diacetate assay. The cytotoxicity of Co(3)O(4)NPs were studied against fibroblast cells. These results altogether bestow the potential for developing Co(3)O(4)NPs based materials with bactericidal properties and biocompatibility for environmental applications. (C) 2017 Elsevier B.V. All rights reserved.