Inner surface biofilm inactivation by atmospheric pressure helium porous plasma jet.

We present a helium porous plasma jet based on gas diffuser, designed with the aim of decontaminating inner surfaces of contaminated structures, e.g., pipes. The porous plasma jet operates with three discharge modes in ambient air and inside a vessel. Its decontamination capacity is demonstrated by evaluating the inactivation efficacy of biofilm form of Pseudomonas aeruginosa, adherent to inner surface of a glass vial. Plasma treatments for 5 min with filament mode and double region helium discharge mode reduced bacterial numbers by 2.4 and 2.5 Log10 CFU/ml. Plasma treatment with double region air‐like discharge mode was the most effective, reducing bacterial cells by 4.5 Log10 CFU/ml, which demonstrates porous plasma jet could provide an efficient approach for inner surface decontamination. A helium porous plasma jet has been presented. With the proper discharge mode, it significantly inactivates Pseudomonas aeruginosa biofilm adherent to the inner surface of a glass vial by greater than 4 Log10 CFU/ml. The porous plasma jet presented can provide an efficient alternative for the inner surface sterilization in relevant sectors, such as medical device, food and pharmacy industries. [ABSTRACT FROM AUTHOR]