Modified polystyrene spheres/graphene oxide decorated with silver nanoparticles as bactericidal material

Abstract

This work describes the preparation of a composite material consisting of Graphene oxide (GO) nanosheets impregnated with silver nanoparticles (AgNPs) synthesized by reduction in situ of adsorbed Ag+ by NaBH4 and over modified polystyrene spheres (PS). PS/GO-AgNPs water dispersion and its film deposited over a polymeric support were tested for their antibacterial activity. The PS/GO-AgNPs composite was characterized by UV–vis spectra, transmission electron microscopy, X-ray diffraction, and scanning electron microscopy. The results obtained by these techniques confirmed the formation of PS/GO composite, they also confirmed the attachment of AgNPs to the GO sheets. The antibacterial activity of this composite was evaluated in seven different bacteria. PS/GO-AgNPs composite performed efficiently in bringing down the count of Bacilus cereus, Escherichia coli, Pseudomonas aeroginosa, Aeromonas hydrophila and Salmonella typhimurium from 106 cfu mL-1 to zero with 200 mg L-1 of PS/GO-AgNPs in water. Results from inhibition halo showed that films containing PS/GO-AgNPs have inhibited the growth of all microbial species in the same magnitude compared to GO-AgNPs. The water dispersed PS/GO-AgNPs composite enabled them to be easily deposited on surfaces, for example, walls or floors in contaminated environments present in hospitals, by a simple spray method to act as a biocidal material, avoiding the undesirable presence of nanoparticle materials (GO-AgNPs) suspended on air.