Eco-friendly synthesis and antibacterial potential of chitosan crosslinked-EDTA silver nanocomposite (CCESN)

Abstract

This study presents a novel and eco-friendly approach for synthesizing silver nanocomposite at room temperature. The method utilizes chitosan derived from snail (Archachatina marginata) shell waste crosslinked with EDTA as a combined reducing and capping agent. The existence of silver nanoparticles in the composite was confirmed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffractometry (XRD), energy dispersive X-ray (EDX), energy dispersive X-ray fluorescence (EDXRF) and thermogravimetric analysis (TGA). The TEM, SEM, XRD, and analyses revealed that the silver nanoparticle has a face-centered cubic structure with an average size of 45.30 nm respectively. EDX and EDXRF showed characteristic silver peaks confirming the formation of silver nanoparticles in the composite while TGA indicated that silver nanoparticles contributed to good thermal stability of the composite. The formation of silver nanoparticles was indicated by a brown color transformation and an ultraviolet visible (UV Vis) absorption peak at 435 nm. The synthesized nanocomposite demonstrated promising antibacterial activity against both Staphylococcus saprophyticus DSM 18669 and Escherichia coli O157 strains, with S. saprophyticus showing higher susceptibility. This highlights the potential of chitosan-EDTA silver nanocomposites as alternative antimicrobial agents.