title: Bactericidal mechanisms of Au@TNBs under visible light irradiation.
abstract: Au@TNBs nanocomposites were synthesized by depositing Au nanoparticles onto the surfaces of TiO2 nanobelts (TNBs). The disinfection activities of Au@TNBs on model cell type, Gram-negative Escherichia coli (E. coli), were examined under visible light irradiation conditions. Au@TNBs exhibited stronger bactericidal properties toward E. coli than those of TNBs and Au NPs under visible light irradiation. The bactericidal mechanisms of Au@TNBs under light conditions were explored, specifically, the specific active species controlling the inactivation of bacteria were determined. Active species (H2O2, diffusing ∙OH, ∙O2-, 1O2, and e-) generated by Au@TNBs were found to play important roles on the inactivation of bacteria. Moreover, the concentrations of H2O2, ·OH, ·O2-, and 1O2 generated in the antimicrobial system were estimated. Without the presence of active species, the direct contact of Au@TNBs with bacterial cells was found to have no bactericidal effect. The reusability of Au@TNBs were also determined. Au@TNBs exhibited strong antibacterial activity toward E. coli even in five consecutively reused cycles. This study indicated that the fabricated Au@TNBs could be potentially utilized to inactivate bacteria in water.
authors: Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Shenzhen Graduate School of Peking University, Shenzhen 518055, PR China; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
authors: Lingqiao
authors: L
authors: Guo
authors: The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
authors: Chao
authors: C
authors: Shan
authors: The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
authors: Jialiang
authors: J
authors: Liang
authors: The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
authors: Jinren
authors: J
authors: Ni
authors: Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Shenzhen Graduate School of Peking University, Shenzhen 518055, PR China; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China. Electronic address: tongmeiping@pku.edu.cn.
authors: Meiping
authors: M
authors: Tong
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects; D015169:Colony Count, Microbial; D004583:Electrons; D017743:Equipment Reuse; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000528:radiation effects; D006046:Gold / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000528:radiation effects; D053761:Nanocomposites / Q000737:chemistry* / Q000528:radiation effects; D013481:Superoxides / Q000737:chemistry; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects
chemical_list: D000900:Anti-Bacterial Agents; D013481:Superoxides; C009495:titanium dioxide; D017665:Hydroxyl Radical; D006046:Gold; D006861:Hydrogen Peroxide; D014025:Titanium
keywords: Active species; Au@TNBs; Disinfection activity; Gold nanoparticles; Reusability