Green nanotechnology in hygiene: antimicrobial efficacy of agar-based trimetallic nanocomposite coating on tissue paper.

This study reports the green synthesis and comprehensive characterization of a trimetallic nanocomposite—AgSnZn@Agar—fabricated using agar-agar as a reducing and stabilizing agent. UV–Vis spectroscopy confirmed the presence of Ag, Sn, and Zn nanoparticles through characteristic absorption peaks at 419, 280, and 360 nm, respectively. FTIR analysis indicated retention of the agar backbone and the emergence of metal–oxygen bonds, while XRD patterns revealed nanocrystalline phases of Ag, SnO₂, and ZnO embedded within a semi-amorphous agar matrix. SEM imaging demonstrated granular surface morphology, and EDS with elemental mapping confirmed uniform dispersion of metallic elements. Importantly, UV–Vis leaching studies showed no detectable release of nanoparticles over 24 h in water, affirming environmental stability. Antifungal and antibacterial assays revealed moderate inhibition zones, particularly against Klebsiella pneumoniae and Staphylococcus aureus, highlighting synergistic antimicrobial potential. Cytotoxicity testing using L929 fibroblasts indicated 84% cell viability, suggesting acceptable biocompatibility. While the antimicrobial activity remains lower than standard antibiotics, the trimetallic nanocomposite presents an eco-safe alternative for surface coatings. This study underscores the importance of a safety-by-design approach rooted in principles of sustainable chemistry, emphasizing the need to minimize environmental impact while maintaining functionality.