Synergistic Action of Reactive Plasma Particles and UV Radiation to Inactivate Staphylococcus Aureus

Abstract

The direct application of low-pressure plasma for the decontamination of microorganisms was examined herein. The inactivation efficiency was studied on a Gram-positive bacterium (Staphylococcus aureus) using a plasma process by means of synergistic action of reactive plasma particles and UV radiation. N2 was added to an argon/oxygen plasma mixture in order to improve the effectiveness of S. aureus inactivation. It was found that the decontamination mechanism is based on both the chemical sputtering effect due to the plasma particles and the UV emission originating from the NOγ system from NO radicals in the wavelength range 200–300 nm. The best plasma bactericidal activity was found for an N2 percentage of roughly 10–12%. A count reduction of more than 5 log cycles in a few minutes of S. aureus proves the potentiality of an industrial-grade plasma reactor as a decontamination agent.