Incorporating Boron into Niobic Acid Nanosheets Enables Generation of Multiple Reactive Oxygen Species for Superior Antibacterial Action.

Abstract

Photocatalytic therapy is an alternative antibacterial pathway but most photocatalysts are limited by light absorption, charge transfer and insufficient production of reactive oxygen species (ROS). Herein, the authors utilize boron doped niobic acid nanosheets (B-HNbO3 NSs) as a superior photocatalytic antibacterial platform. The experimental results and density functional theory (DFT) confirm that superior photocatalytic therapy activity is mainly due to boron doping, which not only promotes the generation and separation of electrons and holes, but also enhances the adsorption of water and oxygen molecules on B-HNbO3 NSs. Consequently, multiple ROS including hydroxyl radicals (•OH), superoxide radicals (•O2- ), and singlet oxygen (1 O2 ) are generated under light irradiation, resulting in outstanding bacterial killing ability of B-HNbO3 NSs. Besides, oxygen is produced during the therapy process, thus alleviating the inflammatory response caused by hypoxia. Furthermore, molecular dynamics (MD) simulations verify that the nanosheet structure makes it possess strong electrostatic attraction for bacterial cell membranes, leading to physical insertion and damage to bacterial cells. Therefore, bactericidal rates for four types of bacteria are all more than 99%, proving its excellent and broad-spectrum antibacterial capacity. Moreover, B-HNbO3 NSs could be applied to treat biofilm-coated medical devices in vivo, suggesting its possibility in practical application.