Sustainable green synthesis of ZnO nanoparticles for antimicrobial and anticancer applications

This study presents a technologically innovative route for the bio-enabled synthesis of zinc oxide nanoparticles (ZnO-NPs), in which Cucumis seed extract is introduced as a previously unexploited and multifunctional nanofactory. The phytochemical-rich extract simultaneously guides nucleation, growth, and surface functionalization, replacing energy-intensive and chemical-intensive routes commonly used in nanomaterial production. The resulting ZnO-NPs, with an average diameter of 11 nm and a well-defined hexagonal wurtzite lattice confirmed through UV-Vis, FTIR, XRD, FE-SEM, and EDX analysis, exemplify nanoscale precision achieved through a low-cost, green strategy. Beyond simple synthesis, the plant-derived surface capping enabled enhanced biological responsiveness, yielding potent anticancer activity against MCF-7 breast cancer cells with an IC₅₀ of 53.74 μg/mL and superior cytotoxic potential compared to the standard reference. Concurrently, the NPs exhibited broad-spectrum antibacterial efficacy, significantly impairing cellular membrane integrity in both Gram-positive and Gram-negative pathogens. This work not only advances a new botanical route for ZnO nanofabrication but also demonstrates how green nanosynthesis can create bioactive, surface-engineered NPs with dual therapeutic capabilities, positioning Cucumis-based nanotechnology as a promising platform for next-generation biomedical applications.