title: Targeted disinfection of E. coli via bioconjugation to photoreactive TiO2.
abstract: The selective control of pathogenic bacteria is an ongoing challenge. A strategy is proposed that combines targeted binding of the bacterium, using antibodies, with their photoactivated oxidative destruction. Photoactive colloidal TiO2 was first derivatized with E. coli antibodies (EA-TiO2). When mixtures of the organisms E. coli and Pseudomonas putida ( P. putida ) were exposed to modified EA-TiO2, the particles preferentially selected E. coli for surface binding. Two consequences arose from surface bioconjugation: bacteria were found to flocculate upon mixing at appropriate ratios of EA-TiO2/ E. coli , and EA-TiO2-bound E. coli underwent cell death after exposure to UV light. In the former case, flocculation of the bacteria was optimal at ~50 EA-TiO2 particles per E. coli . Selective flocculation provides an alternative strategy for pathogen removal. With respect to UV disinfection, as few as 26 EA-TiO2 particles per E. coli gave a 10 000-fold decrease in viable bacteria. Thus, it is possible to selectively target and kill one type of bacteria in a mixture of pathogens. The results give support to the proposal that photocatalytic TiO2 most effectively delivers an oxidizing agent when the titania is bound to the bacterial surface.
authors: Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street, West Hamilton, Ontario, Canada, L8S 4M1.
authors: Lu
authors: L
authors: Ye
authors: Robert
authors: R
authors: Pelton
authors: Michael A
authors: MA
authors: Brook
authors: Carlos D M
authors: CD
authors: Filipe
authors: Haifeng
authors: H
authors: Wang
authors: Luba
authors: L
authors: Brovko
authors: Mansel
authors: M
authors: Griffiths
mesh_terms: D004203:Disinfection / Q000379:methods*; D004926:Escherichia coli / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D010777:Photochemistry / Q000379:methods; D011485:Protein Binding / Q000502:physiology; D014025:Titanium / Q000008:administration & dosage* / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: C009495:titanium dioxide; D014025:Titanium