Sea urchin-like Bi₂S₃/curcumin heterojunction rapidly kills bacteria and promotes wound healing under near-infrared light

Abstract

Bacterial infection is an urgent public health problem. We design a novel photo-responsive hybrid material by growing small molecules of curcumin (Cur) <i>in situ</i> on a sea urchin-like Bi₂S₃ surface by a one-step hydrothermal reaction method, thus forming an organic-inorganic hybrid material with interfacial contact. The Bi₂S₃/Cur hybrid material has good antibacterial effect under 808 nm near-infrared (NIR) light irradiation. The antibacterial mechanism is that the electron redistribution at the interface of Bi₂S₃/Cur excited by 808 nm NIR light will cause a large number of electrons to gather on the side of Bi₂S₃, forming an internal electric field to drive the excited electrons from Bi₂S₃ to Cur, which accelerates the separation of photoexcited electron-hole pairs and enhances the production of reactive oxygen species (ROS). In conclusion, due to these synergistic effects of the photothermal properties of Bi₂S₃, the production of more ROS and the release of small molecules of Cur from traditional Chinese medicine in Bi₂S₃/Cur, the antibacterial efficacy against <i>Staphylococcus aureus</i> (<i>S. aureus</i>) and <i>Escherichia coli</i> (<i>E. coli</i>) is 99.96% and 99.03%, respectively. <i>In vivo</i> experiments in animals show that Bi₂S₃/Cur can reduce the inflammatory response and promote wound healing. This paper presents a simple, rapid and safe strategy for the treatment of wound infections with near-infrared light.