Role of graphene in bactericidal activity and bioactivity of a Zn/graphene/chitosan coating

The antibacterial ability of an implant is governed by the interaction between the surface of the material and the cells. Nanosized features that promote bacterial killing were achieved through synthesizing a Zn/graphene/chitosan surface on a NiTi alloy. The surface morphology and microstructure of the Zn/graphene/chitosan surfaces were observed, and their antibacterial behavior was investigated. The Zn/graphene/chitosan surface exhibited 93 % antibacterial activity against Staphylococcus aureus (S. aureus), which was higher than the Zn/chitosan surface (67 %), and it inhibited bacterial adhesion. This was attributed to the fast release of Zn ions from the Zn/graphene/chitosan surfaces and the sharp morphology of graphene on the surface. In addition, the adhesion of the Zn/graphene/chitosan coating increased with the amount of graphene content. This finding suggests that the synergy of graphene improves the antibacterial ability, bioactivity, and adhesion of Zn-containing coatings.