Visualization of ROS Distribution Generated by Atmospheric Plasma Jet

The distribution patterns of reactive oxygen species (ROS) on a target surface when irradiated by an atmospheric plasma jet need to be understood, especially for biomedical applications. In this paper, a KI-starch agar was used to visualize the distribution of ROS, and the results were compared with sterilization patterns for yeast, which are used to evaluate plasma treatments and are commonly cultivated on agar. Because the agar surface can be affected by gas flow from the plasma jet, the gas exposure time before turning on the plasma was varied and its effects on ROS distribution were observed on the KI-starch agar. It was found that the gas exposure time before plasma irradiation influenced the distribution patterns of the ROS on the KI-starch agar. The mechanism for the pattern formation was explored further via a fine particle visualization experiment.