Synthesis of Silver Nanoparticles Using Green Reducing Agent: Ceylon Olive (Elaeocarpus serratus): Characterization and Investigating Their Antimicrobial Properties

Abstract

Silver nanoparticles (AgNPs) are widely recognized as a prominent antimicrobial agent and have found applications in the field of medicine. This study focuses on the synthesis of AgNPs utilizing the natural reducing agent of Ceylon olive (Elaeocarpus serratus), presenting an economically viable and ecologically friendly approach. For the first time, this research demonstrated the synthesis of AgNPs using phytochemicals extracted from Ceylon olive, serving as both natural reducing and stabilizing agents. The synthesized AgNPs were characterized with UV–visible spectroscopy, a particle size analyzer (PSA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) coupled with an energy dispersive X-ray spectrometer (EDX). The UV–visible spectra primarily indicated the formation of the AgNPs by the surface plasmon resonance band around 434 nm. SEM analysis confirmed the presence of silver nanoparticles within a size range of 50–110 nm, with an average size of approximately 70 nm. FTIR determined that proteins, phenols, and flavonoids may have acted as reducing and capping agents. Experimental parameters were optimized to improve the yield and size of the AgNPs and eventually evaluate their antibacterial properties. The well diffusion method exhibits a significantly larger zone of inhibition for Gram-negative bacterial strains (18.4 ± 0.55 mm for Pseudomonas aeruginosa and 14.4 ± 0.55 mm for Escherichia coli) compared to Gram-positive bacterial strains (11.6 ± 0.55 mm for Staphylococcus aureus and 10.4 ± 0.55 mm for Staphylococcus epidermidis) for 50 µg/mL AgNPs. These findings demonstrate that AgNPs synthesized with Ceylon olive have the potential to develop into novel materials for bacterial-mediated diseases.