Facile synthesis of silver nanoparticles for antibacterial application against multidrug resistant bacteria and antioxidant activity

Abstract

The current study investigated the optimization of physicochemical parameters for the phyto-synthesis of silver nanoparticles (AgNPs) using aqueous extracts from Hibiscus rosa sinensis leaves. The study examined the effects of various factors, including reaction time, temperature, silver nitrate concentration, plant extract volume, and pH on the synthesis of AgNPs. Spectrophotometric analysis indicated optimal conditions for AgNP synthesis at a silver nitrate concentration of 4 mM, a plant extract ratio of 2:8, a temperature of 55 °C, and a pH of 13, resulting in a peak absorption at 419 nm. Fourier Transform Infrared (FTIR) spectroscopy identified the presence of functional groups responsible for capping and stabilizing the AgNPs, while Zeta potential measurements indicated a net surface charge of -29 mV, suggesting stability against agglomeration. X-ray Diffraction (XRD) analysis confirmed the crystalline nature of the synthesized AgNPs, with an estimated particle size of 23.3 nm. The antibacterial activity of the AgNPs was evaluated, showing significant inhibition against various multi drug resistant pathogenic bacteria, with the highest activity against S. flexneri and E. coli. Additionally, the synthesized AgNPs exhibited notable antioxidant activity, demonstrating their potential as therapeutic agents. Overall, this study emphasizes the significance of optimizing synthesis conditions for enhancing the properties of AgNPs and their applicability in biomedical fields.