Abstract

Silver/graphite oxide/chitosan and silver/reduced graphene oxide/chitosan organic–inorganic nanocomposite materials have been synthesized by a precipitation procedure using graphite oxide or reduced graphene oxide acting as stabilizer, silver acetate as Ag0 precursor, sodium hydroxide as reducing medium, and chitosan as covering agent. The synthesized nanomaterials were thoroughly characterized and their antibacterial efficacy investigated in detail, in comparison with chitosan, graphite oxide, reduced graphene oxide, silver/graphite oxide, and silver/reduced graphene oxide, against Gram-positive bacterium Corynebacterium glutamicum and Gram-negative bacterium Escherichia coli strain DH5α, over durations of 8 h and 20 h. The results confirmed that the prepared nanocomposites exhibited broad-spectrum antibacterial activity against the two bacteria. Five μL (2 g/L) of the nanocomposite samples efficiently reduced the number of bacteria from 108 colony-forming units (CFU)/mL to zero. The chitosan layer did not prevent release of Ag from the nanocomposites, demonstrating their potential use as biocidal materials for different applications.