Paper Title
Role Of Zn And Oxygen Vacanciesin Green And Chemically Synthesised Zno Nanoparticles And Their Comparative In Vitro Toxicity Studies For Microbial And Cancer Cell (MCF -7) Models

Abstract
Recently many reports demonstrated on increase in the synthesis of nanoparticles and its applications. The chemical synthesis of nanoparticles may be harmful. Thus, in this study, the biological and toxicology of ZnO nanoparticles (NPs) synthesised through chemical and green routes were compared. Chemically synthesized ZnO NPs were synthesised by co-precipitation method. Gymnema sylvestre aqueous leaf extract was used to prepare ZnO NPs by green synthesis method using stabilizing and reducing agents. ZnO NPs synthesised by both methods were characterized and compared. There was no major significant difference in the nature of the ZnO NPs synthesised by both methods.Photoluminescence and Electron para magnetic studies showed the increased number of oxygen vacancies and interstitial zinc vacancies in the chemically synthesised ZnO NPs, leading to a higher number of Reactive Oxygen Species (ROS) as compared to the green synthesised ZnO NPs. The mode of cell death was assessed through adopting an AO & EB staining. An apoptosis cell death, a minimum concentration of 55 μg/ml for chemically synthesised ZnO NPs was well enough to induce 50% cell mortality as compared to green synthesised ZnO NPs (65 μg/ml). In vitro antibacterial and anticancer activities of ZnO NPs synthesised by chemical and green route suggest that these NPs, prepared by green route possess reliable anticancer and antibacterial activity. Evaluation of toxicity in microbial and cell line suggests that ZnO NPs synthesized by green route are nontoxic. Keywords: Toxicology, Green route, Gymnema sylvestre, antibacterial studies, anticancer studies