Preparation and characterization of GO/ZnO/Ag nanocomposites and their synergistic antibacterial effect on Streptococcus mutans

Abstract

In this study, GO/ZnO/Ag nanocomposites were prepared by a hydrothermal method in one step. The microstructure and surface morphology of the material were analyzed by x-ray diffraction and a scanning electron microscope. The chemical interactions between the available oxygen functional groups of reduced graphene oxide and the inorganic parts (Ag and ZnO) were analyzed by XPS and FTIR. The synergistic antibacterial activity of the nanocomposites against Streptococcus mutans was investigated. It was confirmed that GO/ZnO/Ag could inhibit the growth of S. mutans. The minimal inhibitory concentration and minimum bactericidal concentration of GO/ZnO/Ag on the surface structure of S. mutans were 62.5 and 125 µg/ml, respectively. The material was added to a dental dentin binder, and the modified dentin binder specimens with GO/ZnO/Ag had a significant antibacterial effect against Streptococcus mutans. The results showed that a low dose of GO/ZnO/Ag did not affect the shear bond strength of the dentin binder (P > 0.05), while a high dose of GO/ZnO/Ag decreased the shear bond strength of the dentin binder (P < 0.05). With an increase in GO/ZnO/Ag, the contact angle of the modified dentin binder specimens decreased and the hydrophilicity increased. The nanocomposites can not only be used as antibacterial agents but also have potential applications in biomedical fields.