A 2D-2D heterojunction Bi<sub>2</sub>WO<sub>6</sub>/WS<sub>2-x</sub> as a broad-spectrum bactericide: Sulfur vacancies mediate the interface interactions between biology and nanomaterials.

Hou, Xuan; Shi, Tonglei; Wei, Changhong; Zeng, Hui; Hu, Xiangang; Yan, Bing · Biomaterials · 2020

basic_science · Level V

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Abstract

We report a heterojunction Bi<sub>2</sub>WO<sub>6</sub>/WS<sub>2-x</sub> with sulfur vacancies as a broad-spectrum bactericide to efficiently kill Gram-positive and Gram-negative bacteria in vitro and in vivo under visible-light irradiation. Sulfur vacancies in single-layer WS<sub>2</sub> make the surface electron-rich. Integration of Bi<sub>2</sub>WO<sub>6</sub> with WS<sub>2</sub> enhances the photoelectric activity under visible-light irradiation. Sulfur vacancies promote the generation of radicals and the extraction of membrane phospholipids from bacterial cells. Density functional theory verifies that S vacancies strengthen the interactions between the Bi<sub>2</sub>WO<sub>6</sub>/WS<sub>2-x</sub> surface and H<sub>2</sub>O, enhancing the generation of ·OH. Two-dimensional correlation spectroscopy analysis reveals that perturbation of β-sheet proteins and formation of outer-sphere surface complexes contribute to the high antibacterial capacity. Bi<sub>2</sub>WO<sub>6</sub>/WS<sub>2-x</sub> accelerates the re-epithelialization and healing of infected wounds in an animal model. Uncommonly, Bi<sub>2</sub>WO<sub>6</sub>/WS<sub>2-x</sub> does not exhibit drug resistance and is biocompatible with human cells. Our results indicate that vacancy-functionalized heterojunctions are potentially promising antibacterial agents by regulating the interface interaction between biology and nanomaterials.

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