Silver-N-Carboxymethyl Chitosan Nanocomposites: Synthesis and its Antibacterial Activities

In this work, silver-N-carboxymethyl chitosan nanocomposites (Ag-N-CMC) were synthesized in the homogeneous state via the reduction of Ag+ (using [Ag(NH3)2]OH instead of AgNO3) by NaBH4 in the presence of water-soluble N-carboxymethyl chitosan as a stabilizer. The resulting Ag-N-CMG was characterized by FTIR, TEM and UV-vis spectra. The results showed that the average particle size of silver nanoparticles was little affected by the concentration of Ag+ added and was between 2 and 10nm. The characteristic surface plasmon resonance band of silver nanoparticles centered at about 398 - 410nm. In vitro antibacterial activities of Ag-N-CMC nanocomposites were evaluated against both gram-negative bacteria: Escherichia coli ATCC 25922 (Ec) and Pseudomonas aeruginosa VM201 (Pseu) and gram-positive bacteria: Staphylococcus aureus ATCC 1128 (Sta) and Bacillus cereus ATCC 9946 (Bc). The results shown that the Ag-N-CMC nanocomposites could inhibit the growth and multiplication of the tested bacteria.