Biological Activities of Boron and Reduced Graphene Oxide-Based Zinc Oxide Nanocomposites (ZnO:B and RGO/ZnO:B) Synthesized by an Environmentally Friendly Method

Abstract

In this study, a graphene oxide material was fabricated using the Hummers process. RGO, ZnO, ZnO:B and RGO/ZnO:B nanoparticles were synthesized by the hydrothermal method in an autoclave at a temperature of 160 degrees C. The structural and morphological changes in the synthesized ZnO nanomaterials were investigated by preparing composite materials with a boron additive and RGO. The prepared nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Antimicrobial and antibiofilm assays were performed to evaluate the biological activities of the synthesized nanoparticles. The antimicrobial activity of these NPs was investigated against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis and Staphylococcus epidermidis pathogenic bacteria. Among the nanoparticles tested, ZnO and ZnO:B NPs showed strong antimicrobial activity against clinically important E. coli, P. aeruginosa and B. cereus strains. The antibiofilm activity of the synthesized nanoparticles was determined using E. coli and P. aeruginosa strains. The biofilm inhibition of both strains by the ZnO:B nanocomposites was greater than that by the other nanocomposites. At a concentration of 20 mg/mL, the ZnO:B nanocomposite showed 42.13% biofilm inhibition of E. coli and 36.21% biofilm inhibition of P. aeruginosa. The RGO/ZnO:B nanocomposite had a specific inhibitory effect on E. coli (34.25%) and P. aeruginosa (30.16%). The antibiofilm effect of the nanocompounds used in the study was greater on E. coli than on P. aeruginosa. As a result, the synthesized boron-reinforced ZnO nanocomposites exhibited strong biological effects. These results will provide valuable information for the development of new treatment regimens for the inactivation of pathogenic bacteria.