Bismuth@Bismuth Sulfide Core@Shell Structure for Near Infrared II Light Triggered Photothermal Therapy

Abstract Near infrared (NIR) light, especially NIR‐II, triggered photothermal therapy has gained increasing attention due to its deep tissue penetration ability. The development of new NIR‐II photothermal agent may accelerate the clinical translation. As a semiconductor, bismuth (Bi) can be activated by NIR‐II light. Herein, we developed Bi@bismuth sulfide (Bi 2 S 3 ) core@shell nanoparticles (NPs) as new NIR‐II triggered PTA. The photothermal conversion efficiency of Bi@Bi 2 S 3 NPs was calculated to be 48.39 %. With 1064 nm laser irradiation, Bi@Bi 2 S 3 NPs could effectively induce temperature elevation and kill cancer cells. In vivo experiments further prove that Bi@Bi 2 S 3 NPs can serve as an efficient photothermal agent with well biocompatibility for tumor elimination.