Cu Enhances the Photothermal Effect of a Tin Film for Antibacterial Applications

In recent years, diseases caused by the spread of hazardous microorganisms (e.g., bacteria) have become a growing global concern. Imparting antimicrobial properties to the surface of a material is critical for the prevention of bacterial disease transmission. In this study, titanium nitride/copper composite (TiN-Cu-X) films with excellent antibacterial properties were deposited on AISI 304 stainless steel (304ss) via magnetron sputtering. The TiN-Cu-X composite films exhibited excellent photothermal performance under near-infrared (NIR, 808 nm) irradiation: the temperature of a TiN-Cu-X composite film surface exposed to a bacterium-containing medium increased rapidly, resulting in the death of bacteria on the surface (similar to 100 %). The TiN-Cu-600 film exhibited 70.8 % antibacterial activity owing to the release of Cu2+ in the absence of NIR irradiation. The TiN-Cu-X composite films prepared in this study demonstrated outstanding antibacterial capabilities owing to synergy between the photothermal effect and Cu2+ release. The TiN-Cu-X composite films prepared in this study are intended for use as photothermal antibacterial coatings and represent a new approach for the production of antibacterial coatings on material surfaces.