Antibacterial Activity of Polypyrrole-Chitosan Nanocomposite: Mechanism of Action

Polypyrrole-chitosan nanocomposite (PPy-CTN) was synthesized by dispersion polymerization of PPy in presence of CTN. Preparation of spherical PPy nanoparticles that were successfully covered with a thin layer of chitosan was confirm by transmission electron microscopy (TEM) technique. Characterization techniques also revealed the presence of CNT in the polymer matrix and its presence was confirmed by the shift of absorption band in fourier transform infrared spectroscopy (FTIR). The prepared polymer was then tested for the antibacterial properties against Gram-negative bacteria; Escherichia coli (E. coli) bacteria. The antibacterial property was assessed by disk diffusion method. The results showed clearly that, PPy-CTN nanocomposite strongly inhibit the growth of wild-type E. coli (20 ± 0.5 mm) followed by PPy (11 ± 0.5 mm) and CTN (2 ± 0.5 mm). The PPy-CTN nanocomposite exhibits a significant enhancement in antibacterial activity better than that of pristine PPy and CTN. In particular mechanisms of antibacterial action in PPy-CTN nanocomposite were discussed.