A microphotoreactor method has been developed to generate bubbles containing singlet oxygen. The disinfection method described here produces bubbles enriched in singlet oxygen.  The photocatalyst was physically separated from the liquid and so cannot inadvertently contaminate the solution.  Singlet oxygen bubbles were fount to oxidize compounds and inactivate Escherichia coli, mainly by an oxygen gradient inside and outside of the bubble such that singlet oxygen is solvated and diffuses through the aqueous solution until it reacts with the target organism.  Only the first millisecond needs to be considered since singlet oxygen has decayed to an insignificant concentration after that time.  The mechanism by which singlet oxygen deactivated organisms was explored through the addition of detergent molecules and calcium ions.  Results indicate that the preferential accumulation of E. coli at the air-water interface of the bubble leads to enhanced toxicity of bubbles containing singlet oxygen.

On the mechanism of singlet oxygen reactions: Inner-bubble reactions

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.