title: Plasmon-induced inactivation of enteric pathogenic microorganisms with Ag-AgI/Al2O3 under visible-light irradiation.
abstract: The plasmon-induced photocatalytic inactivation of enteric pathogenic microorganisms in water using Ag-AgI/Al(2)O(3) under visible-light irradiation was investigated. The catalyst was found to be highly effective at killing Shigella dysenteriae (S. dysenteriae), Escherichia coli (E. coli), and human rotavirus type 2 Wa (HRV-Wa). Its bactericidal efficiency was significantly enhanced by HCO(3)(-) and SO(4)(2-) ions, which are common in water, while phosphate had a slightly positive effect on the disinfection. Meanwhile, more inactivation of E. coli was observed at neutral and alkaline pH than at acid pH in Ag-AgI/Al(2)O(3) suspension. Furthermore, the effects of inorganic anions and pH on the transfer of plasmon-induced charges were investigated using cyclic voltammetry analyses. Two electron-transfer processes occurred, from bacteria to Ag nanoparticles (NPs) and from inorganic anions to Ag NPs to form anionic radicals. These inorganic anions including OH(-) in water not only enhanced electron transfer from plasmon-excited Ag NPs to AgI and from E. coli to Ag NPs, but their anionic radicals also increased bactericidal efficiency due to their absorbability by cells. The plasmon-induced electron holes (h(+)) on Ag NPs, O(2)(•-), and anionic radicals were involved in the reaction. The enhanced electron transfer is more crucial than the electrostatic force interaction of bacteria and catalyst for the plasmon-induced inactivation of bacteria using Ag-AgI/Al(2)O(3).
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
authors.forename: Xuexiang
authors.initials: X
authors.lastname: Hu
authors.forename: Chun
authors.initials: C
authors.lastname: Hu
authors.forename: Tianwei
authors.initials: T
authors.lastname: Peng
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Zhou
authors.forename: Jiuhui
authors.initials: J
authors.lastname: Qu
mesh_terms: D000537:Aluminum Oxide / Q000494:pharmacology*; D002384:Catalysis / Q000187:drug effects / Q000528:radiation effects; D004203:Disinfection; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000472:pathogenicity / Q000528:radiation effects; D004926:Escherichia coli / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects / Q000528:radiation effects; D007454:Iodides / Q000494:pharmacology*; D007477:Ions; D007700:Kinetics; D008027:Light; D050296:Microbial Viability / Q000187:drug effects / Q000528:radiation effects*; D012401:Rotavirus / Q000187:drug effects / Q000528:radiation effects; D012760:Shigella / Q000187:drug effects / Q000528:radiation effects; D012834:Silver / Q000494:pharmacology*; D018030:Silver Compounds / Q000494:pharmacology*; D013997:Time Factors; D038301:Virus Inactivation / Q000187:drug effects / Q000528:radiation effects*
chemical_list: D007454:Iodides; D007477:Ions; D018030:Silver Compounds; D012834:Silver; C030584:silver iodide; D000537:Aluminum Oxide