Electron spin resonance (ESR) study of radicals on biological organism created by interaction with plasma

For bio-applications of atmospheric pressure plasmas, our group has been reported previously that inactivation of microorganisms such as fungal spores of Penicillium digitatum by employing high-density non-equilibrium atmospheric pressure plasma [1]. To understand a mechanism of inactivation, there needs analysis of reactions between plasmas and biomaterials. It has long been appreciated that radicals play important roles for controlling the reactions. The electron-spin-resonance (ESR) technique can detect the radicals - in particular dangling bonds - and thus we have developed methods to utilize the ESR for this purpose [2]. In this study, we focused on ESR detection of radical on biological organism as exampled of the Penicillium digitatum interacted with plasmas.