Inactivation of Staphylococcus aureus bythe synergistic action of charged andreactive plasma particles

In this paper, a low-pressure capacitively coupled plasma discharge sustained in an argonoxygenmixture was studied in order to evaluate its properties in terms of inactivation ofStaphylococcus aureus. The plasma parameters as electron temperature and plasma density weremeasured by the Langmuir probe (N_e ≈ 10¹⁵ m⁻³, T_e ≈ 1.5 eV), while the neutral atom densitywas in the range of 10²¹ m⁻³. In the plasma phase, oxygen radicals were taken as reference of thereactive species with antimicrobial activity, and oxygen spectral lines, over a range of plasmaprocess parameters, were investigated by the optical emission spectroscopy. Optimal plasmaconditions were found, and a count reduction of 4 log in a few minutes of the bacterium provesthe potentiality of an industrial grade plasma reactor as a sterilization agent.