Novel nanoblades of graphene oxide decorated with zinc oxide nanocomposite as a powerful anti-microbial active weapon

Graphene-based materials have emerged as new green broad-spectrum antibacterial agents with low bacterial resistance and sustained release properties. In the current work, a novel graphene-ZnO hybrid nanocomposite was prepared as an effective antibacterial weapon with a blade-like structure. Graphene oxide nanosheets decorated with ZnO nanospheres (GO/ZnO) were facilely prepared and controlled via a one-phase method. Nano-GO with 2 nm-thick sheets was prepared via a modified Hummers` procedure. A wet-chemical process was used to produce controlled 60 nm-ZnO nanospheres. Analytical methods such as field emission TEM and SEM microscopes were used to characterize the produced nanocomposites. Several gram-positive and gram-negative bacteria were used to test the anti-microbial activity of the developed materials. Through the microdilution method, GO/ZnO composites showed outstanding antibacterial activity with minimum inhibitory concentrations of 20 µg/mL for S. aureus, Bacillus subtilis, B. pertussis, as well as 40 µg/mL for H. pylori and P. aeruginosa . GO/ZnO nanocomposite’s bacterial resistance was mediated via nanoblade-edges, cellular rupture, and generation of reactive oxygen species. We concluded that a considerable quantity of oxidative stress created on the composite surface was involved in the bactericidal pathway and was responsible for eradicating the mature biofilm. ZnO NPs` dispersion in an aqueous solution was boosted by GO nanosheets, which also prevented aggregation and enhanced the anti-microbial performance.