Designing chitosan–silver nanoparticles–graphene oxide nanohybrids with enhanced antibacterial activity against Staphylococcus aureus

Abstract

Abstract Designing hybrid nanomaterials that exhibit multiple mechanisms of antibacterial action provides a new paradigm in the fight against resistant bacteria. Herein, we present such a new hybrid nanomaterial which integrates the antibacterial and physico-chemical properties of silver nanoparticles, graphene oxide and chitosan biopolymer. The formation, stability and structure of the integrated three-component chitosan-silver nanoparticles–graphene oxide (chit–AgNPs–GO) nanomaterial is analyzed by UV–vis extinction spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. The antibacterial activity is evaluated against two representative methicillin-resistant Staphylococcus aureus (MRSA) strains (UCLA 8076 and 1190R) and relative to individual components (GO, chit–GO, AgNPs–GO) by determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The three-component nanocomposites (chit–AgNPs–GO) exhibit higher antibacterial activity than most of the antibacterial agents based on AgNPs or AgNPs–GO reported so far and, more interestingly, their activity can be controlled by the ratio between the amount of chitosan and AgNPs–GO. The results presented in this study demonstrate the promising potential of the chit–AgNps–GO hybrids as effective nanomaterial to fight against the bacterial infections.