Green mediated synthesis of silver nanoparticle using Euphorbia Maculate leaf extract and their catalytic reduction and antibacterial properties

Abstract

Conventional methods for silver nanoparticles (AgNPs) synthesis often rely on harsh chemicals and hazardous reducing agents, raising concerns about environmental pollution and toxicity. This study reports the green synthesis of AgNPs using Euphorbia maculata (EM) leaf extract as a reducing and capping agent. This one-pot synthesis, conducted at room temperature, offers a simple, rapid, and cost-effective alternative to conventional methods. Additionally, it eliminates the need for external stabilizers or reducing agents, making it environmentally friendly and sustainable. Surface plasmon resonance (SPR) peak at 430 nm in the UV–vis spectrum indicated the successful synthesis of AgNPs. High-resolution transmission electron microscopy (HR-TEM) analysis revealed spherical AgNPs with an average diameter of approximately 10.85 nm. X-ray diffraction (XRD) pattern confirmed the AgNPs to be face-centered cubic (FCC) crystalline. Fourier-transform infrared spectroscopy (FTIR) analysis identified the presence of phenolic compounds in the EM extract, which are responsible for the reduction of silver ions and act as natural stabilizers. Additionally, a pH optimization study revealed that a pH of 9 is optimal for producing AgNPs. AgNPs-EM exhibited potent antibacterial activity against both Gram-positive and Gram-negative bacteria, with a stronger effect observed against E. coli. Additionally, they displayed excellent catalytic activity for the reduction of o-nitroaniline.