Reactive oxygen species (ROS) supplied into liquids by plasma irradiation must be identified and controlled for the safe and effective use of plasmas in biomedical applications. This study aims to obtain information on the key ROS regarding ROS transportation through a liquid layer for realization of spatial ROS identification. Two-dimensional distributions of ROS after passing through liquids with and without ROS scavengers were visualized and compared to assess the suppression effects of each scavenger using a measurement system combined with a gel ROS detector. The plasma was generated under helium and 1% oxygen mixture gases. It was experimentally confirmed that a hydroxyl radical is not a key species, whereas, superoxide anion radicals and hydrogen peroxide play a key role for ROS transportation in our system. The results also suggested that the chemical processes for ROS transportation change at a liquid layer thickness of less than 1mm.

必须识别和控制通过等离子体辐射供应到液体中的活性氧（ROS），以在生物医学应用中安全有效地使用等离子体。这项研究旨在获得有关通过液层传输ROS的关键ROS的信息，以实现空间ROS的识别。可视化通过具有和不具有ROS清除剂的液体后，ROS的二维分布，并使用测量系统与凝胶ROS检测器相结合，比较以评估每种清除剂的抑制效果。在氦气和1％的氧气混合气体下产生等离子体。实验证明，羟基不是关键物种，而超氧阴离子自由基和过氧化氢在我们系统中的ROS转运中起关键作用。