Antimicrobial Synergy Between Ambient-Gas Plasma and UVA Treatment of Aqueous Solution

作者：Pavlovich Matthew J; Sakiyama Yukinori; Clark Douglas S^*; Graves David B

来源：Plasma Processes and Polymers, 2013, 10(12): 1051-1060.

DOI：10.1002/ppap.201300065

• bacterial inactivation
• dielectric barrier discharges (DBD)
• non-thermal plasma
• photochemistry
• UV-photons

We describe the photochemical and antimicrobial synergy between ambient-condition air plasma and ultraviolet photons at near-UV (UVA) wavelengths. Plasma treatments generate reactive oxygen and nitrogen species in aqueous solution. When UVA treatment followed plasma treatment of Escherichia coli, the antimicrobial effect exceeded the effect predicted from the two treatments alone. Exposing individual plasma-associated species to UVA photons indicated that the synergy is associated with nitrite and hydrogen peroxide in combination. An antioxidant present during UVA treatment prevented the synergistic effect, suggesting oxidant-mediated bacterial inactivation. Addition of nitrite to aqueous solution, followed by photolysis of nitrite by UVA photons, is hypothesized as the primary mechanism of synergy.

• 出版日期2013-12