Bio-Mediated Zinc Oxide Nanoparticles through Tea Residue: Ecosynthesis, Characterizations, and Biological Efficiencies

Recent advances in nanotechnology have placed a major emphasis on environmentally friendly processes that encourage sustainable growth by using moderate reaction conditions and non-toxic precursors. In the present study, a simple, inventive, and affordable green technique was applied to generate bio-augmented ZnO nanoparticles using an aqueous extract of tea residue as a reducing and stabilizing component. Numerous methods, including UV-Vis, XRD, FT-IR, FE-SEM with EDAX and TEM were used to analyze ZnO nanoparticles that were generated. The antimicrobial capabilities of biomediated ZnO nanoparticles against pathogenic organisms were examined using an agar well method. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT assay) and flow cytometry analysis was utilized to explore cytotoxic effects and apoptosis, and methylene blue dye was used to examine photocatalytic activity. The ZnO nanoparticles demonstrated considerable anticancer activity in human lung cancer cells (A549) as well as highly effective antibacterial activity against several different microbial pathogens. Furthermore, the greatest degradation percentage of methylene blue obtained was found to be 86% after 140 min. Therefore, it is concluded that the chosen nanoparticle combination enhanced antimicrobial, anticancer and photocatalytic activities. The combination may represent a useful tool for removing dye pollution from wastewater and, ideally, be used in the pharmaceutical sector to combat lung cancer.