Plasma activated liquids: New decontamination solutions

In the field of new decontaminants, there is an increasing consensus that improved disinfection of environmental surfaces is needed in patient care facilities as an important component in the overall strategy for prevention of HAI. The interaction of cold atmospheric plasma, i.e. an ionized gas, with liquids results in complex physical and chemical processes, which offer a source of short-lived and long-lived reactive chemical species that are critical for microbial inactivation. These solutions may fulfil the urgent need for new decontaminant solutions for special purposes such as disinfection of surfaces, or use as an antiseptic for body surfaces.

In this study, we explored the bactericidal effects of plasma activated liquids (PALs) on E.coli and S. aureus strains and investigated factors which influence PALs stability over time. Liquids of interest were non-complex solutions such as water and saline. An atmospheric cold plasma system using air was employed for the generation of PALs. The solutions were compared with respect to their content of long-lived reactive chemical species and bactericidal effects.

Our results documented that PALs may carry different concentrations of chemical species and maintain diverse antimicrobial properties. The bactericidal activity of these solutions demonstrated high thermal stability and could be preserved over a 6 month period through specific sub-ambient storage conditions. Investigation of the inactivation processes in relation to the PALs’ chemical composition will enhance our knowledge on how prokaryotic and eukaryotic cells respond to these, and demonstrate how PALs could be a promising treatment method for future applications, with chemical and antimicrobial stability.