BACKGROUNDThe present study explores the synthesis of chitosan-metal nanocomposites in view of their increasing application as antimicrobial material. RESULTSChitosan nanoparticles were prepared by ionic gelation between chitosan and sodium tripolyphosphate. Copper sulphate hydrate (CuSO4.5H(2)O) and zinc acetate (Zn (O2CCH3)(2)) were used as precursors for synthesis of chitosan-copper nanocomposites (Cu/Ch) and chitosan-zinc nanocomposites (Zn/Ch), respectively. Synthesis of nanocomposites was confirmed by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy with energy dispersive X-ray microanalyses (SEM-EDX) and differential scanning calorimetry (DSC). Cytotoxicity of nanoformulations was studied by Resazurin assay on Vero cell line (African green monkey kidney cell line). Their antibacterial activities were assessed by the zone of inhibition method and time dependent growth curve against Micrococcus luteusMTCC 1809, Pseudomonas aeruginosaMTCC 424 and Salmonella entericaMTCC 1253 in vitro. Antifungal activity was also studied against Alternaria alterneta, Rhizoctonia solani and Aspergillus flavus in vitro by the mycelium inhibition method. CONCLUSIONSIt was observed that all nanoformulations show high antimicrobial activity against all test microorganisms. So chitosan-metal complexes could be promising candidates for novel antimicrobial agents in cosmetic, food and textile industries. (c) 2014 Society of Chemical Industry