title: Zinc oxide nanorod mediated visible light photoinactivation of model microbes in water.
abstract: The inactivation of model microbes in aqueous matrix by visible light photocatalysis as mediated by ZnO nanorods was investigated. ZnO nanorods were grown on glass substrate following a hydrothermal route and employed in the inactivation of gram-negative Escherichia coli and gram-positive Bacillus subtilis in MilliQ water. The concentration of Zn(2+) ions in the aqueous matrix, bacterial cell membrane damage, and DNA degradation at post-exposure were also studied. The inactivation efficiencies for both organisms under light conditions were about two times higher than under dark conditions across the cell concentrations assayed. Anomalies in supernatant Zn(2+) concentration were observed under both conditions as compared to control treatments, while cell membrane damage and DNA degradation were observed only under light conditions. Inactivation under dark conditions was hence attributed to the bactericidal effect of Zn(2+) ions, while inactivation under light conditions was due to the combined effects of Zn(2+) ions and photocatalytically mediated electron injection. The reduction of pathogenic bacterial densities by the photocatalytically active ZnO nanorods in the presence of visible light implies potential ex situ application in water decontamination at ambient conditions under sunlight.
authors: Center of Excellence in Nanotechnology, Asian Institute of Technology, Klong Luang, Pathumthani 12120, Thailand.
authors: Ajaya
authors: A
authors: Sapkota
authors: Alfredo J
authors: AJ
authors: Anceno
authors: Sunandan
authors: S
authors: Baruah
authors: Oleg V
authors: OV
authors: Shipin
authors: Joydeep
authors: J
authors: Dutta
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects / Q000528:radiation effects; D001419:Bacteria / Q000187:drug effects* / Q000528:radiation effects*; D004926:Escherichia coli / Q000187:drug effects / Q000528:radiation effects; D008027:Light; D043942:Nanotubes / Q000737:chemistry*; D014871:Water Microbiology; D015034:Zinc Oxide / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D015034:Zinc Oxide