Luminescent Silver Nanoparticles Biosynthesis Using Couroupita guianensis Flower Extract: Antibacterial and Anticancer Potential

ABSTRACT Green synthesis of nanoparticles has become a significant area of research, driven by the demand for sustainable, economical, and environmentally friendly processes, particularly in biomedical applications. In this study, silver nanoparticles (AgNPs) were produced using 10 g of Couroupita guianensis flower extract through a straightforward and environmentally friendly method. The biosynthesized AgNPs were characterized using UV–Vis spectroscopy, XRD, FTIR, SEM, and EDS techniques, confirming their successful formation and structural properties. The antibacterial efficacy of the AgNPs was assessed against Escherichia coli and Listeria monocytogenes, achieving 99.5% inactivation for E. coli and 99.3% inactivation for L. monocytogenes after 120 min of visible light exposure. Additionally, the AgNPs showed notable anticancer effects against breast cancer cells (MDA‐MB‐231), displaying a dose‐dependent decrease in cell viability, with reductions of 15%, 30%, 72%, and 86% observed at concentrations of 25, 50, 75, and 100 μg/mL, respectively. The spherical morphology of the synthesized AgNPs contributed to enhanced interactions with bacterial and cancer cells, underpinning their effectiveness. Furthermore, the mechanisms underlying these antibacterial and anticancer effects were analyzed, highlighting the unique phytochemical properties of the extract that assist in biosynthesis and activity enhancement. These findings suggest that green‐synthesized AgNPs derived from C. guianensis flower extract hold significant potential for use in biomedical applications, particularly in antibacterial and anticancer therapies. Silver nanoparticles (AgNPs) were synthesized using Couroupita guianensis flower extract through an eco‐friendly green synthesis approach. The AgNPs displayed strong antibacterial properties, effectively inactivating Escherichia coli and Listeria monocytogenes under visible light conditions. Furthermore, the AgNPs showed significant anticancer action against breast cancer cells, resulting in notable reductions in cell viability at varying concentrations.