Silver-zinc oxide nanocomposites: Synthesis and evaluation of antimicrobial and anticancer activities

Abstract

This study presents the green synthesis of silver-zinc oxide (Ag-ZnO) nanocomposites utilizing the leaf extract of Verbascum speciosum. The synthesis was confirmed through various characterization techniques: Fourier-transform infrared spectroscopy (FTIR) revealed Zn-O vibrations and the presence of hydroxyl and carboxyl groups; powder X-ray diffraction (PXRD) confirmed the crystalline nature of the nanocomposites; field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) provided insights into the morphology and particle size; dynamic light scattering (DLS) and zeta potential measurements indicated particle size distribution and surface charge, respectively. The synthesized Ag-ZnO nanocomposites exhibited significant antibacterial activity against Escherichia coli and Staphylococcus aureus, with the efficacy being concentration- and time-dependent. Cytotoxicity assays demonstrated selective toxicity, with higher cytotoxicity observed against human liver carcinoma (HepG2) cells compared to normal NIH-3T3 cells, indicating potential anticancer properties. These findings underscore the potential of Verbascum speciosum-mediated Ag-ZnO nanocomposites as effective antimicrobial and anticancer agents, offering a sustainable approach to nanomaterial synthesis.