Abstract
Conventional Zinc oxide nanoparticle (ZnO NPs) synthesis techniques employ toxic elements that are hazardous to both human being and the environment. When compared to previous approaches, the green chemistry technique for nanoparticle synthesis is faster, cost-effective, more environmentally friendly, and less hazardous. In this work, we used a green chemistry strategy to prepare ZnO NPs from Camellia sinensis tea leaf extract. These green-synthesized ZnO NPs were characterized through analytical techniques such as UV, XRD, SEM, EDS, DLS and FTIR. These ZnO NPs were found to be of spherical shape having sizes ranging from 6 to 112 nm. The synthesized ZnO NPs showed greater antimicrobial activity against gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus). In addition, the green-synthesized ZnO NPs showed best antioxidant [2,2-diphenyl-1-picryl-hydrazyl and Hydrogen peroxide radical scavenging method] activities at increasing concentrations. Also, the ZnO NPs prepared in this study were biocompatible and showed antitumor activity against HeLa cells following a 48-h exposure period. The green-synthesized ZnO NPs did not cause harm to healthy human cells, which is confirm their biocompatibility. These characteristics are promising, implying that ZnO NPs synthesized from green chemistry route using Camellia sinensis tea leaf extract could be potential candidates for anti-infections and anticancer drugs in pharmaceutical applications.