title: Comparative toxicity of Cd, Mo, and W sulphide nanomaterials toward E. coli under UV irradiation.
abstract: In this study, the phototoxicity of cadmium sulfide (CdS), molybdenum disulfide (MoS2), and tungsten disulfide (WS2) nanoparticles (NPs) toward Escherichia coli (E. coli) under UV irradiation (365 nm) was investigated. At the same mass concentration of NPs, the toxicity of three NPs decreased in the order of CdS > MoS2> WS2. For example, the death rates of E. coli exposed to 50 mg/L CdS, MoS2, and WS2were 96.7%, 38.5%, and 31.2%, respectively. Transmission electron microscope and laser scanning confocal microscope images of E. coli exposed to three NPs showed the damage of cell walls and release of intracellular components. The CdS-treated cell wall was more extensively damaged than those of MoS2-treated and WS2-treated bacteria. WS2and MoS2generated superoxide radical (O2-), singlet oxygen (1O2), and hydroxyl radical under UV irradiation, CdS produced only O2-and1O2. CdS and WS2released ions under UV irradiation, while MoS2did not. Reactive oxygen species (ROS) generation and toxic ion release jointly resulted in the antibacterial activities of CdS and WS2. ROS generation was the dominant toxic mechanism of MoS2toward the bacteria. This study highlighted the importance of considering the hazardous effect of sulfide NPs after their release into natural waters under light irradiation condition.
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
authors.forename: Enxiang
authors.initials: E
authors.lastname: Shang
authors.affiliation: School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan, 523808, PR China.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Niu
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China. Electronic address: liyang_bnu@bnu.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
authors.forename: Yijing
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: School of Civil and Environmental Engineering and the Brook Byers Institutue for Sustainable Systems, Georgia Institute of Technology, Atlanta, 30332, Georgia.
authors.forename: John Charles
authors.initials: JC
authors.lastname: Crittenden
mesh_terms: D002104:Cadmium / Q000633:toxicity*; D017484:Dermatitis, Phototoxic; D004926:Escherichia coli / Q000187:drug effects*; D008027:Light; D008982:Molybdenum / Q000633:toxicity*; D053758:Nanoparticles / Q000633:toxicity*; D013440:Sulfides / Q000633:toxicity*; D014414:Tungsten / Q000633:toxicity*; D014466:Ultraviolet Rays
chemical_list: D013440:Sulfides; D002104:Cadmium; D008982:Molybdenum; D014414:Tungsten
keywords: Dissolution; E. coli; Phototoxicity; Reactive oxygen species; Sulfide nanoparticle