Green synthesis of Ag-doped CeO2 nanoparticles with carboxymethyl chitosan: characterization, UV protection, & antioxidant effects

Abstract

This study presented the synthesis of cerium dioxide (CeO₂) nanoparticles utilizing carboxymethyl chitosan (CMC) to augment their biocompatibility with subsequent silver doping to refine their properties. The undoped CeO₂ nanoparticles were characterized as a cubic fluorite crystal structure with an average particle size of approximately 17.5 nm. The undoped CeO₂ nanoparticles preserved the cubic fluorite crystal structure and spherical morphology of the nanoparticles; however, it induced modifications in their physical properties, including a reduction in particle size and unit cell volume and an expansion of lattice spacing. Cytotoxicity assays revealed that undoped CeO₂ nanoparticles did not exhibit cytotoxic effects on HaCaT cells within the defined concentration range, indicating that CeO₂ nanoparticles synthesized with CMC significantly enhanced their biocompatibility. The silver-doped CeO₂ nanoparticles demonstrated enhanced antioxidant activity and an elevated sun protection factor (SPF) compared to their undoped counterparts. The enhancement of these properties highlights their potential applications in biomedicine and cosmetics.