[24a-D113-6~6] 8.6 Plasma Electronics English Session

▲ [24a-D113-6] Cold plasma-induced modification of the paramagnetic species of the radish and barley seeds

〇(PC)Pankaj Attri¹, Takamasa Okumura¹, Kazunori Koga^1,2, Masaharu Shiratani¹ (1.Kyushu Univ., 2.Nat. Inst. Nat. Sci.)

Keywords:Plasma agriculture, Electron paramagnetic resonance (EPR) spectroscopy

The use of cold plasma treatment of seeds benefits over conventional treatments due to short treatment time and low-temperature operations [1,2]. During plasma treatment interacts with the oxygen, nitrogen, water, etc. in air, to produce various radical and non-radical species [3]. The germination starts with the appearance of the radicle from the seed coat when the seeds absorb water at suitable environmental conditions [4]. Electron paramagnetic resonance (EPR) spectroscopy is optimal for interpreting any change in paramagnetic defect centers. The use of free radical species as precursors to identify the changes in the biological systems due to physical or chemical stress. The detection of the change in paramagnetic species before and after seed treatment is of great interest. Therefore, we used EPR spectroscopy in this study to detect the changes that occurred in seeds before and after plasma treatment. We observed that scalar DBD treatment on radish sprouts seed coat increases organic free radical intensity. The weak peak at g = 4.3 represents the signal for Fe³⁺, hyperfine lines belonging to the Mn²⁺ peaks, and an intense sharp rise at g = 2.0 attribute to the semiquinone radical. This shows that the pattern of the peaks is the same, although, on a close look, we observed the change in EPR peak intensities after the plasma treatment. Our results are useful to understand the possible change in paramagnetic species on the seed coat after interaction with plasma-generated RONS.