Biomimetically Synthesized Zinc Oxide Nanoparticles Using Black Elderberry ( <i>Sambucus nigra</i> ) Fruit Extract for Anticancer Activity Against SH‐SY5Y Neuroblastoma Cancer Cells

Abstract The biomimetic synthesis of zinc oxide nanoparticles offers a sustainable strategy for anticancer applications by minimizing off‐target toxicity and side effects associated with conventional chemotherapy. In this study, nanoscaled ZnO NPs (denoted as sn ‐ZnO NPs) were synthesized under ambient conditions using a biomimetic approach with Sambucus nigra (black elderberry) fruit extract as a natural reducing and capping agent, and zinc acetate dihydrate as the precursor. Morphological, structural, and optical characterizations including FESEM, EDX, XRD, FTIR, and UV–visible spectroscopy confirmed the successful synthesis of hexagonal wurtzite‐structured nanoparticles with an average size of 53 ± 10 nm. The influence of calcination temperatures (500–700 °C) on the structural and optical properties of the nanoparticles was systematically examined. Higher calcination temperatures increased crystallite size and bandgap energy ranging from 1.67 eV (as‐synthesized) to 2.67 eV (700 °C). The nanoparticles demonstrated significant in vitro anticancer activity against SH‐SY5Y neuroblastoma cells with the 600 °C sample exhibiting the highest cytotoxicity achieving an IC 50 value of 9.48 µg/mL. These eco‐friendly, biocompatible sn ‐ZnO NPs with tunable structural and optical properties demonstrate strong potential for biomedical applications particularly in targeted cancer therapy and lay a foundation for further research into their use in diverse biomedical and environmental fields.