Green synthesis of novel chitosan-graphene oxide-silver nanoparticle nanocomposite for broad-spectrum antibacterial applications

Abstract In this study, a novel nanocomposite composed of chitosan, graphene oxide, and silver nanoparticles (CS-GO-Ag NPs) is presented and synthesized using pulsed laser ablation. Characterization techniques, including X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy EDX, and UV-visible spectroscopy, confirm successful synthesis. The XRD results reveal that the CS-GO-Ag NPs exhibit crystalline structures with an average crystallite size of approximately 30 nm. FE-SEM analysis shows a heterogeneous mixture of nanoparticles, ranging in size from 32.38 to 174.9 nm. The EDX spectra elucidate the elemental composition, while UV-Vis spectroscopy indicates strong interactions among the components, yielding a direct bandgap of 2.33 eV and an indirect bandgap of 1.2 eV, suggesting efficient light absorption and emission for applications in Light emitted Diode (LEDs) and solar cells. Furthermore, the CS-GO-Ag NPs nanocomposite displays enhanced antibacterial activity against both gram-negative and gram-positive bacteria when it compared to its individual components. According to characterization tests, well-dispersed silver nanoparticles were formed into a ternary nanocomposite, successfully. The enhanced antibacterial capabilities including increased bacterial cell membrane disruption and oxidative stress can be attributed to the synergistic interaction between the components. The outcomes highlight the CS- GO-Ag NPs nanocomposite's potential as a promising antimicrobial agent for numerous applications including the biomedical fields and water treatment industries.