Fungal-Mediated Green Synthesis of ZnO–MnO Nanocomposites with Antimicrobial and Anticancer Properties

Abstract The urgent need for sustainable therapeutic nanomaterials has driven interest in green synthesis routes. In this study, zinc oxide–manganese oxide nanocomposites (ZnO–MnO NCs) were mycosynthesized using the extracellular filtrate of Aspergillus terreus . Characterization by UV–visible spectroscopy, FTIR, XRD, TEM, and DLS confirmed their crystalline structure, functional groups, and nanoscale morphology. The NCs showed a distinct absorption at ~ 320 nm with average particle sizes of 75 nm (TEM) and 99 nm (DLS). Antibacterial assays revealed strong activity against Escherichia coli and Bacillus subtilis , with inhibition zones surpassing ceftriaxone and MIC values of 64–256 µg/mL. Time-kill analysis demonstrated rapid bacterial reduction at higher doses. Cytotoxicity studies indicated good safety in normal cells (IC₅₀ = 360.7 µg/mL) and potent anticancer activity against MCF-7 cells (IC₅₀ = 106.25 µg/mL). These findings highlight fungal-mediated biosynthesis as an eco-friendly route for producing ZnO–MnO NCs with antimicrobial and anticancer potential.