Exploring the biological properties of ZnO and CuO based nanoparticles prepared from Theobroma cacao L. leaf extract: a promising approach for nanomedicine

This study pioneers the biogenic synthesis of zinc oxide-copper oxide (ZnO-CuO) bimetallic nanoparticles (BNPs) using Theobroma cacao L. leaf extract, offering a novel and eco-friendly approach to nanoparticle development. Characterization techniques, including UV-visible spectroscopy and FTIR analysis, confirmed successful synthesis, while XRD revealed the crystalline nature of ZnO and CuO NPs, with ZnO-CuO BNPs exhibiting face-centered cubic (FCC) and hexagonal Wurtzite structures. FESEM and HRTEM analyses provided insights into morphology, and zeta potential measurements (−35.4, −36.1, and −46.9 mV) demonstrated nanoparticle stability. Thermal properties were assessed using TGA and DSC. ZnO-CuO BNPs exhibited superior biological activity compared to their monometallic counterparts. They demonstrated significant antibacterial, antioxidant, and angiogenic properties in a dose-dependent manner. In in vitro cytotoxicity assays, ZnO-CuO BNPs showed enhanced anticancer efficacy, with IC50 values against HCT-15 cells at 8.27 ± 0.47 µg/mL and against A549 cells at 7.28 ± 0.09 µg/mL, outperforming ZnO and CuO nanoparticles. Additionally, ZnO-CuO BNPs displayed a remarkable anti-ROS effect, highlighting their therapeutic potential. These findings underscore the superiority of ZnO-CuO BNPs over monometallic nanoparticles, positioning them as promising candidates for biomedical applications, particularly in antibacterial and anticancer therapies.