Abstract Cold atmospheric pressure plasma has emerged as a promising tool for various bioapplications due to its capability to generate a rich mixture of reactive agents. However, it is often unclear to what extent individual plasma agents, such as ions, reactive neutral species, and UV radiation, contribute to the observed biological effects. This study addresses this issue by using a multi-hollow surface dielectric barrier discharge in combination with an electrical grid and optical window to separate and investigate the effects of individual plasma agents. Ion current measurements, optical emission spectroscopy, and FTIR spectroscopy were employed to characterize the plasma agents formed in ambient air, nitrogen, and oxygen. Experiments on the inactivation of bacteria Salmonella typhimurium showed different effects of individual plasma agents depending on the working gas. The effect of UV radiation was observed only in nitrogen, supported by the results of optical emission spectroscopy. Unlike in air, where ion presence had no observable effect, distinct outcome in oxygen indicated a specific role of oxygen ions. In experiments with pBR322 plasmid DNA, the highest damage was observed in air, followed by oxygen and nitrogen, with no significant difference between treatments with and without ions. In oxygen, however, UV-induced damage was prominent, contrasting with bacteria inactivation and probably linked to the formation of reactive oxygen species, as indicated by DMSO scavenging test.
Kuťka et al. (Mon,) studied this question.