title: Antibacterial activity of two-dimensional MoS2 sheets.
abstract: Graphene-like two-dimensional materials (2DMats) show application potential in optoelectronics and biomedicine due to their unique properties. However, environmental and biological influences of these 2DMats remain to be unveiled. Here we reported the antibacterial activity of two-dimensional (2D) chemically exfoliated MoS2 (ce-MoS2) sheets. We found that the antibacterial activity of ce-MoS2 sheets was much more potent than that of the raw MoS2 powders used for the synthesis of ce-MoS2 sheets possibly due to the 2D planar structure (high specific surface area) and higher conductivity of the ce-MoS2. We investigated the antibacterial mechanisms of the ce-MoS2 sheets and proposed their antibacterial pathways. We found that the ce-MoS2 sheets could produce reactive oxygen species (ROS), different from a previous report on graphene-based materials. Particularly, the oxidation capacity of the ce-MoS2 sheets toward glutathione oxidation showed a time and concentration dependent trend, which is fully consistent with the antibacterial behaviour of the ce-MoS2 sheets. The results suggest that antimicrobial behaviors were attributable to both membrane and oxidation stress. The antibacterial pathways include MoS2-bacteria contact induced membrane stress, superoxide anion (O2(˙-) induced ROS production by the ce-MoS2, and the ensuing superoxide anion-independent oxidation. Our study thus indicates that the tailoring of the dimension of nanomaterials and their electronic properties would manipulate antibacterial activity.
authors.affiliation: State Key Laboratory of Silicon Materials, MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China. msxu@zju.edu.cn hzchen@zju.edu.cn.
authors.forename: Xi
authors.initials: X
authors.lastname: Yang
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Tao
authors.initials: T
authors.lastname: Liang
authors.forename: Chunyan
authors.initials: C
authors.lastname: Ma
authors.forename: Yingying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hongzheng
authors.initials: H
authors.lastname: Chen
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Hanagata
authors.forename: Huanxing
authors.initials: H
authors.lastname: Su
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Xu
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000138:chemical synthesis; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004220:Disulfides / Q000008:administration & dosage* / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D008422:Materials Testing; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry* / Q000648:ultrastructure; D008982:Molybdenum / Q000008:administration & dosage* / Q000737:chemistry*; D010316:Particle Size
chemical_list: D000900:Anti-Bacterial Agents; D004220:Disulfides; D008567:Membranes, Artificial; D008982:Molybdenum; C082964:molybdenum disulfide