Study of effect of atmospheric pressure plasma on biological specimen by using in situ real time electron spin resonance technique

常压等离子体对病原体的杀菌作用因其无化学药剂、电气操作等优点而备受关注。等离子体产生原子氧、激发氧、羟基自由基、激发态氮、一氧化二氮等多种活性化学物质，但这些物质与真菌孢子、微生物等生物标本的相互作用还不完全清楚。特别是活性物质故意暴露在生物样品中，作者着重于了解等离子体灭菌过程中的自由基。利用原位实时电子自旋共振(ESR)技术，成功地观察到了指状青霉真菌孢子中的自由基。ESR信号的衰减与孢子的失活有关，因此作者发现ESR技术检测到的自由基与真菌孢子失活的生物反应密切相关。

Atmospheric pressure plasma sterilization of pathogens is now paid much attention for usefulness of no chemicals, electrical operations and so on. The plasma generates many kinds of reactive chemical species such as atomic oxygen, excited oxygen, hydroxyl radical, excited nitrogen, nitrous oxide, etc. However, interactions these species with biological specimens such as fungal spores, microorganisms etc. have not been clarified completely. In particular of intentional exposure of the reactive species to the biological specimen, the author has focused on understanding of free-radicals during plasma sterilization. Employing in situ real time electron spin resonance (ESR) technique, observation of free radical on the fungal spore of Penicillium digitatum has been succeeded. ESR signal decay is linked with inactivation of the spore, therefore the author found the close correlation of the free radical detected by ESR technique with biological response of inactivation on the fungal spores.