Green synthesis, characterization and bioactivity analysis of eco-friendly silver nanoparticles using <i>Schefflera actinophylla</i> flowers

Abstract The synthesis of nanoparticles (NPs) has gained prominence due to their distinct properties and wide-ranging applications. Among various methods, green synthesis stands out for its environmentally friendly approach. This study investigates the green synthesis of silver nanoparticles (AgNPs) using the aqueous extract of Umbrella plant flowers ( Schefflera actinophylla ). Phytochemical analysis of the extract identified the presence of alkaloids, terpenoids, saponins, resins, carbohydrates, and phenols. Silver nanoparticles were synthesized using a 0.1 M AgNO 3 solution and monitored through UV-visible spectroscopy, which revealed an absorption peak at 370 nm. Characterization through infrared (FTIR) spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM), Dynamic Light Scattering (DLS), and Zeta potential measurements indicated an average particle size of 8.9 nm and a zeta potential of −8.8 mV. FE-SEM images showed nanoparticles in various shapes. The AgNPs exhibited significant antimicrobial activity against common bacteria such as Staphylococcus aureus , Bacillus subtilis , Pseudomonas aeruginosa , and Escherichia coli , as well as fungi including Aspergillus niger and Candida albicans . Furthermore, the nanoparticles displayed notable antioxidant activity with an IC 50 value of 37.025 μg/ml. This study highlights the benefits of using plant-based methods for nanoparticle synthesis, offering an eco-friendly alternative to conventional chemical processes, thus reducing pollution and mitigating antibiotic resistance in microbes.