[Near-infrared Excited Graphene Oxide/silver Nitrate/chitosan Coating for Improving Antibacterial Properties of Titanium Implants]

Objective: To design and construct a graphene oxide (GO)/silver nitrate (AgPO)/chitosan (CS) composite coating for rapidly killing bacteria and preventing postoperative infection in implant surgery.

Methods: GO/AgPO composites were prepared by ion exchange method, and CS and GO/AgPO composites were deposited on medical titanium (Ti) sheets successively. The morphology, physical image, photothermal and photocatalytic ability, antibacterial ability, and adhesion to the matrix of the materials were characterized.

Results: The GO/AgPO composites were successfully prepared by ion exchange method and the heterogeneous structure of GO/AgPO was proved by morphology phase test. The heterogeneous structure formed by AgPO and GO reduced the band gap from 1.79 eV to 1.39 eV which could be excited by 808 nm near-infrared light. The photothermal and photocatalytic experiments proved that the GO/AgPO/CS coating had excellent photothermal and photodynamic properties. antibacterial experiments showed that the antibacterial rate of the GO/AgPO/CS composite coating against reached 99.81% after 20 minutes irradiation with 808 nm near-infrared light. At the same time, the composite coating had excellent light stability, which could provide stable and sustained antibacterial effect.

Conclusion: GO/AgPO/CS coating can be excited by 808 nm near infrared light to produce reactive oxygen species, which has excellent antibacterial activity under light.