Green synthesis of silver nanoparticles using Senecio vernalis and evaluation of their multifunctional biomedical, sun protection factor and catalytic degradation activities

Abstract

Green synthesis has emerged as a safe and sustainable alternative to conventional chemical methods because it avoids the use of toxic reagents and enables environmentally friendly nanoparticle production. In this study, silver nanoparticles were prepared through a green approach using an aqueous extract of Senecio vernalis (S@AgNPs). The synthesis was optimized by varying AgNO 3 concentration, temperature, reaction time, and pH. The synthesized S@AgNPs were characterized using X-ray diffraction, energy-dispersive X-ray spectroscopy, transmission electron microscopy, scanning electron microscopy, and ultraviolet-visible spectroscopy. The average particle size of S@AgNPs was 11.23 ± 5.84 nm. They exhibited potent antibacterial activity against Staphylococcus aureus , Pseudomonas aeruginosa , and Escherichia coli , with a minimum inhibitory concentration (MIC) of 0.29 µg/mL. They also demonstrated significant antiparasitic activity, strong antioxidant activity (IC 50 = 25 ± 2.99 µg/mL), an sun protection factor (SPF) of 29.4, and remarkable α-glucosidase inhibitory activity (IC 50 =1.8 ± 0.3 ng/mL). Furthermore, they efficiently catalyzed the degradation of methyl orange (> 70%, during 24 min.), rhodamine B (> 95%, during 35 min.), and 4-nitrophenol (> 33%, during 30 min.) in the presence of NaBH₄. Catalytic results were confirmed by UV and FTIR spectra. These findings demonstrate the potential of green-synthesized S@AgNPs as multifunctional nanomaterials for biomedical, cosmetic, and environmental applications.