Facile synthesis of Ag/GNS-g-PAA nanohybrids for antimicrobial applications

A facile and efficient aqueous phase-based strategy to synthesize silver nanocrystal/graphene nanosheet (GNS) nanohybrids at room temperature, via in situ poly(acrylic acid) (PAA) grafting followed by attachment of Ag nanocrystals, was reported. In the presence of PAA-grafted GNSs, Ag nanoparticles were in situ generated from AgNO3 aqueous solution without any additional reducing agent or complicated treatment. They readily attached to the GNS surfaces, leading to Ag/GNS-g-PAA nanohybrids. The products of the Ag/GNS-g-PAA nanohybrids were examined by transmission electron microscope, thermogravimetric analyzer, X-ray powder diffraction analyzer, and energy disperse spectroscopy. The Ag nanoparticles can be uniformly deposited on the surfaces of functionalized GNSs with a controlled size distribution of 4–8 nm. Furthermore, the Ag/GNS-g-PAA nanohybrids exhibit good antimicrobial activity against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The mean diameters of the zones of inhibition are 11.4 mm and 9.9 mm, respectively, for S. aureus and E. coli. The simplicity, efficiency and large-scale availability of nanohybrids combined with good antimicrobial activity make them attractive for graphene-based biomaterials.