Eco-friendly synthesis and antibacterial evaluation of CuO, ZnO, and CuO–ZnO nanostructures supported by DFT and molecular docking

Plant extract-mediated synthesis of metal oxide nanoparticles (MO NPs) offers a sustainable route for biomedical applications due to their biocompatibility and eco-friendly production. In this work, copper oxide (CuO), zinc oxide (ZnO), and novel CuO-ZnO nanocomposites were successfully synthesized using phytochemicals from Pistacia eurycarpa leaves. The nanostructures were comprehensively characterized by XRD, UV-Vis, SEM, EDX, and FTIR analyses, confirming crystalline phases with nanoscale spherical and rod-like morphologies. The optical band gaps (1.6-2.74 eV) indicated suitability for diverse functional applications. The antibacterial activity of the synthesized nanomaterials was evaluated against Escherichia coli and Staphylococcus aureus, revealing significant inhibitory and bactericidal effects. Complementary density functional theory calculations provided insights into their electronic properties, while molecular docking studies demonstrated strong binding interactions with bacterial target proteins Staphylococcus aureus dihydrofolate reductase (2W9H), Escherichia coli DNA gyrase B (6F86) and Estrogen receptor alpha (ERα) (5GS4), supporting their potential bioactivity. Overall, this combined experimental and computational study highlights the promising antibacterial potential of green-synthesized CuO, ZnO, and CuO-ZnO nanostructures and underscores their applicability as eco-friendly agents for biomedical applications.