Interactions of Atmospheric Pressure Plasma Jets and Microorganism: Inactivation

Abstract

Plasma is used for many applications such as coating, cleaning, etc. Atmospheric pressure plasma jets can also be used for sterilization. Different types of gases, different electrode design and different microorganism types have been tried for better inactivation recently. Alternative current cold atmospheric pressure (ACP) argon and argon-hydrogen mixture plasmas at the dielectric barrier discharge-like (DBD-like) systems are separately used in this experiment. Different types of microorganism such as Enterecoccus faecalis, Escherichia coli, Bacillus subtilis, Candida albicans, Candida glabrata, Candida krusei and Listeria monocytogenes were used for the inactivation tests in this study. The main aim was to see the differences of sterilization effect between pure argon and argon-hydrogen mixture discharges by using the new system and to compare the effects of plasma sterilization with different daily disinfectants. It is concluded that the inactivation effects of argon-hydrogen plasma generally have better effect than pure argon discharge. Further investigation of microorganism viability by scanning electron microscopy (SEM) demonstrated that ACP treatment had a detrimental effect on the Escherichia coli and Candida albicans cells through disintegration of both prokaryotic and eukaryotic cells. The results of this study demonstrate the potential of an ACP decontamination approach for the inactivation of different microorganisms.