Sterilization of Staphylococcus Aureus by an Atmospheric Non-Thermal Plasma Jet

An atmospheric non-thermal plasma jet was developed for sterilizing the Staphylo- coccus aureus (S. aureus). The plasma jet was generated by dielectric barrier discharge (DBD), which was characterized by electrical and optical diagnostics. The survival curves of the bacteria showed that the plasma jet could effectively inactivate 10⁶ cells of S. aureus within 120 seconds and the sterilizing efficiency depended critically on the discharge parameter of the applied voltage. It was further confirmed by scanning electron microscopy (SEM) that the cell morphology was seriously damaged by the plasma treatment. The plasma sterilization mechanism of S. aureus was attributed to the active species of OH, N₂ ⁺ and O, which were generated abundantly in the plasma jet and characterized by OES. Our findings suggest a convenient and low-cost way for sterilization and inactivation of bacteria.