Three types of gases, pure argon (99.999), argon with 2 oxygen, and argon with 2 oxygen and 10 nitrogen were used as operating gases of a direct current atmospheric pressure cold plasma jet to inactivate Staphylococcus aureus (S. aureus) suspended in a liquid. The inactivation efficacies for the plasma jets operating in the three gases decrease from Ar/O 2(2) to Ar/O 2(2)/N 2(10) to pure Ar. Optical emission spectroscopy, electron spin resonance spectroscopy, high performance liquid chromatography, and atomic absorption spectrophotometry were employed to identify and monitor the reactive species in the plasma-liquid system for the three operating gases and revealed the presence of O, 1O 2, OH, NO, H 2O 2, O 3, and NO 3 -/NO 2 - as well as Cu +/Cu 2. The S. aureus inactivation results indicate that atomic oxygen (O) is the key inactivation agent, while other species play a lesser role in the inactivation progress studied here.
ASJC Scopus subject areas
- Physics and Astronomy(all)