Facile synthesis and synergistic cytotoxic effect of Ag/Co-ZnO nanoparticles in epithelial breast cancer cells

Here in, silver-cobalt (Ag/Co) incorporated in ZnO nanoparticles (NPs), referred to as Ag/Co-ZnO NPs, were synthesized using a facile co-precipitation method. The as-synthesized samples were characterized using ultraviolet-visible spectroscopy, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis techniques. The optical band gap of ZnO and Ag/Co-ZnO NPs increased from 3.64 to 3.92 eV when the Ag/Co concentration was increased by 10–30%. The incorporated ZnO exhibits increased antibacterial activities. DPPH and OH radical scavenging showed that the as-synthesized samples were antioxidants. Furthermore, pure ZnO and Ag/Co-ZnO were tested for cytotoxicity on MDA and BHK-21 breast cancer and skin cells, respectively. IC50 values for ZnO and Ag/Co-ZnO NPs against the MDA cell lines were 3.58 and 4.206 µg/mL, respectively. Antibacterial activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria were also tested. Ag/Co-ZnO outperformed ZnO in antibacterial activity. Molecular docking was used to predict the interaction and binding affinities of undoped ZnO and Ag/Co incorporated ZnO for antioxidant, anticancer, and antibacterial studies against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria using Auto Dock Vina. The promising biological and antimicrobial activities of Ag/Co-ZnO NPs highlight their potential for development into multifunctional therapeutic and biomedical agents. Future studies may focus on optimizing dopant ratios to further tune optical and biological properties, conducting in vivo evaluations to validate biocompatibility and therapeutic efficacy, and exploring their integration into drug-delivery systems, wound-healing formulations, and antibacterial coatings.