[21a-W621-1~12] 8.6 Plasma life sciences

▲ [21a-W621-11] Rate of O₃ production in DBD chamber and its effect on spore surface modification

〇(D)Mohammad Rasel Pervez, Takanori Inomata¹, Tatsuo Ishijima¹, Makiko Kakikawa¹, Yasunori Tanaka¹, Yohishiko Uesugi¹, Toshihiro Yano², Shoji Miwa³, Akinori Noguchi⁴ (1.kanazawa univ., 2.Kanazawa Gakuin Junior College, 3.Ishikawa Agri. Forest. Res. Cent., 4.Sodick Co., Ltd.)

Keywords:Non-thermal plasma spore inactivation,surface modification,Ozone production

Direct or indirect exposure to non-thermal atmospheric pressure plasma (NAPP) can inactivate microbes and cancer cells. As observed in scanning electron microscopic (SEM) images of microorganisms, plasma exposure causes irreversible outer wall damage. Reason for this outer wall destruction is not clear yet but various reactive oxygen and nitrogen species (RONS) produced in the discharge zone and afterglow region are considered to be the main chemical etchants. In this experiment we have used He as main feed gas. Keeping the gas flow rate and applied voltage constant, O₂ admixture ratio is varied. O₃ density within DBD chamber is not constant but depends on the O₂ admixture ratio in the feed gas channel. O₃ density in the DBD chamber is maximum for the feed gas composition He + 1.5% O₂. Surface morphology of spores undergone direct and remote plasma exposure were observed by FE-SEM imaging technique. Surface morphology of spores undergone direct plasma exposure is significantly different than the spores’ undergone remote treatment.