Enzyme-like antibacterial activities of Cu9S5 nanoflowers with vacancy-type dependence

Abstract

Due to the increasing drug resistance of bacteria and the limitations of antibacterial nanomaterials through photodynamical and photothermal routes, it is necessary to develop novel nanomaterials with outstanding enzyme-like activities and bacteria-binding capability to produce reactive oxygen species (ROS) to kill bacteria. Herein, we report the synthesis of two kinds of Cu 9 S 5 nanoflowers composed of assemblies of nanosheets, abbreviated as Cu 9 S 5 -1 and Cu 9 S 5 -2, which possess predominantly V CuSCu and V CuSS vacancies, respectively, as confirmed by the positron annihilation spectra. Both experimental and theoretical calculation results reveal that Cu 9 S 5 -2 exhibits excellent enzyme-like activities because of stronger bacteria-binding ability and higher electron affinity that endow it with a superior antibacterial activity compared to Cu 9 S 5 -1. This study provides a deeper understanding of nanomaterials with vacancy-type-dependent enzyme-like activities and insights for the rational design of high-performance antibacterial agents in the future. Cu 9 S 5 -1 and Cu 9 S 5 -2 nanoflowers possess V CuSCu and V CuSS vacancies, respectively Cu 9 S 5 -2 displays excellent bacteria-binding ability and higher electron affinity Cu 9 S 5 -2 exhibits better enzyme-like antibacterial properties compared with Cu 9 S 5 -1 Chen et al. synthesize two kinds of Cu 9 S 5 nanoflowers with different vacancies and report that Cu 9 S 5 -2 (with V CuSS vacancies) possesses excellent enzyme-like antibacterial properties due to stronger electron affinity and adsorption compared to Cu 9 S 5 -1 (with V CuSCu vacancy). This finding may provide new insights for the design of high-performance antibacterial materials.