Plant assisted synthesis of gold nanoparticles from leaf aqueous source of Glinus oppositifolius; characterization, and evaluation of antibacterial and DPPH activities efficacy

Synthesizing metal nanoparticles through Green methods has become an essential alternative to conventional methods. In the present study, gold nanoparticles (AuNPs) were synthesized using the aqueous leaf extract of Glinus oppositifolius as a reducing and stabilizing agent. The formation of AuNPs was confirmed by a characteristic surface plasmon resonance peak at 533 nm using UV–Visible spectroscopy. Particle size analysis by dynamic light scattering (DLS) revealed an average size of 99.4 nm, while the zeta potential value of −31.2 mV indicated good stability of the synthesized nanoparticles. The biological activities of the synthesized AuNPs were evaluated for antibacterial and antioxidant potential. Antibacterial activity was assessed against Escherichia coli, Klebsiella pneumoniae, Bacillus subtilis, and Enterococcus faecalis using the agar well diffusion method. Among the tested strains, the highest zone of inhibition was observed against Bacillus subtilis (20.5 mm), indicating strong antibacterial efficacy. Additionally, the antioxidant activity was determined using the DPPH radical scavenging assay, where the AuNPs exhibited significant activity with 83.44% inhibition at 100 µL concentration. By the results, this study demonstrates that Glinus oppositifolius-mediated synthesis of gold nanoparticles is a simple and sustainable approach, yielding stable nanoparticles with notable antibacterial and antioxidant properties, suggesting their potential applications in biomedical and pharmaceutical fields.