Abstract
An atmospheric-pressure argon (Ar) plasma jet was applied to disinfect against Escherichia coli (E. coli). The Ar plasma jet was generated at a frequency of 9 kHz, applied voltage of 10 kV, and Ar gas flow rate of 10 L/min at atmospheric-pressure. The length and the diameter of the Ar plasma jet was approximately 3 cm and 6 mm, respectively. E. coli seeded on an agar plate in a Petri dish was exposed to the Ar plasma jet. E. coli was disinfected by Ar plasma jetexposure for 2 s. The results of temperature and emission measurements for the Ar plasma jet indicated disinfection effects were neither due to the heat nor due to the light from the Ar plasma jet. The results of scanning electron microscopy (SEM) observation showed the E. coli cells deformed and faded after the Ar plasma jet exposure. Therefore, the disinfection of E. coli was probably due to the destruction of cell wall and cell membrane caused by the collision of charged particles such as Ar ions, electrons and metastable excited atoms and molecules.
