Measurements of Plasma-Generated Hydroxyl and Hydrogen Peroxide Concentrations for Plasma Medicine Applications

摘要

Low-temperature, atmospheric pressure plasmas (LTPs) produce reactive oxygen and nitrogen species [O, O2−, O2 ( 1Δ ), hydroxyl (OH), H2O2, NO, NO2 … ]. In biological and medical applications, the concentrations and fluxes of these species play a crucial role in the biological outcomes. Many of these species are produced in the gaseous phase and at the gas-liquid interface when LTP is applied to biological media. In the medium, the plasma-produced oxygen reactive species and nitrogen reactive species generate long-lived species, such as hydrogen peroxide (H2O2), nitrites (NO2−), nitrates (NO3−), and organic peroxides (RO2). In particular, hydrogen peroxide is known to cause various oxidizing reactions in biological cells. One of the pathways to the creation of hydrogen peroxide is the reaction between OH radicals. Therefore, the measurement of OH concentration is of great importance. In this paper, we report on the measurements of OH in the gas-liquid interface using laser-induced fluorescence and measurements of H2O2 concentration in biological media. In addition, the effects of plasma activated media on cancer cells are briefly discussed.