▎ 摘　　要

NOVELTY - Preparation of film-forming nanocomposite comprising silver nanoparticles, reduced graphene oxide, chitosan and tannic acid comprises mixing graphene dispersion with silver precursor to obtain silver-graphene composite, mixing composite with protonated chitosan solution and tannic acid to form chitosan-silver-graphene composite, pouring composite to Petri plates, drying at less than 60 degrees C to form stand-alone film, mixing or coating composite dispersion with inert-solid material obtain thin film of composite on surfaces, and cross-linking with obtained stand-alone film using trisodium citrate. USE - Method for preparing film-forming nanocomposite used for water disinfecting media for disinfecting pathogenic organism in water within permissible limit (all claimed). ADVANTAGE - The composite is capable of acting as silver reservoir and protects silver nanoparticles from interacting with other ions and natural organic matter present in water, and shows excellent antibacterial property against gram-negative and gram-positive bacteria including Escherichia coli, Staphylococcus aureus, Proteus vulgaris, Enterococcus faecalis, Klebsiella pneumoniae and Pseudomonas aeruginosa. The composite is also hydraulically stable and can stay in the water for long duration without any chemical or physical change.