Antimicrobial activity of silver/starch/polyacrylamide nanocomposite

A novel silver/starch/polyacrylamide nanocomposite hydrogel was prepared by grafting acrylamide onto starch in presence of silver nitrate by use of ammonium persulphate as an initiator and N,N-methylene-bisaciylamide as a crosslinking agent, then reducing the silver ions enclosed in the hydrogel structure to silver nanoparticles by treating the hydrogel with sodium hydroxide solution. All factors which affect the grafting/crosslinking reaction were optimized and the concentration of silver ion was changed from 0 ppm to 50 ppm. The produced nanocomposite hydrogel was characterized for its nanosilver content and the UV-spectra showed similar absorption spectra at wavelength 405 nm for all AgNO3 concentrations but the plasmon showed increase in the intensity of the absorption peak as AgNO3 concentration incorporated to the hydrogel structure increases. The nanocomposite hydrogel was also characterized for its antimicrobial activity toward two types of bacteria and two types of fungi. The results showed that the hydrogel with 0 ppm silver content has no antimicrobial activity, and that the antimicrobial activity expressed as inhibition zone increases as the silver content increases from 5 ppm to 50 ppm. (C) 2014 Elsevier B.V. All rights reserved.