## 3 Results
### Chemical Comparison and Mock Treatment Are Inaccurate Markers of Cellular Responses
The model predicted that OH was the initiator of the reaction by forming the glutathione radical (-S*), which is known to react quickly with H\({}_{2}\)O\({}_{2}\) and form glutathione sulfenic acid (GSOH) in biological systems [55]. The MD simulations also showed that glutathione radicals could react with OH, NO, or another glutathione radical to form GSOH, S-nitrosogluathione (GSNO), and glutathione disulfide (GSSG), respectively, in the liquid phase [23]. The presence of GSOH and the \(\
u\) (S=O) band in our nspDBD-treated samples indicated the presence of OH and subsequent oxidation to form higher oxidation states. These states were GSOH, GSO\({}_{2}\)H, and GSO\({}_{3}\)H, the latter two corresponding to the \(\
u\) (S=O) band. [PERSON] et al. observed that significantly more GSO\({}_{3}\)H than GSO\({}_{2}\)H was produced by DBD treatment through mass spectrometry [23]. This type of oxidation is irreversible in biological systems [56], indicating the highly oxidative environment of microsecond pulse DBD treatment, as shown by [PERSON] et al. [23], as well as that of the nspDBD treatment, as presented here. Although the COST-Jet treated samples reduced the \(\
u\) (S-H) band similar to the nspDBD-treated samples, an increase of the \(\
u\) (S=O) mode was not observed. Instead, an increase of the \(\
u\) (S-S) band was observed in the COST-Jet-treated samples, which was more pronounced for the 4-min treatment. In the case of the COST-Jet, there was little OH generated with an admixture of O\({}_{2}\). Instead, production of O, O\({}_{3}\), and singlet oxygen (O\({}_{2}\)(a\({}^{1}\)Ag)) was magnified [48; 57; 58]. It was likely that the dominant mechanism to form the glutathione radical was through H abstraction by O rather than OH. However, there was not enough oxidation to form GSO\({}_{3}\)H, as indicated by the absence of the \(\
u\) (S=O) mode. While this showed GSO\({}_{3}\)H was not produced, the lower oxidation states might still be formed, indicating a less oxidative environment. This was expected between the two treatments since the end product of the ROS, H\({}_{2}\)O\({}_{2}\), was lower for COST-Jet treatments. The differences in GSH modifications between the COST-Jet and nspDBD suggested there might be different pathways of inducing oxidative stress and reducing the viability of Jurkat cells. Oxidation of the glutathione radical leads to the formation GSOH [55]. Further oxidation forms glutathione sulfinic acid (GSO\({}_{2}\)H) and glutathione sulfonic acid (GSO\({}_{3}\)H), whereas GSO or GSSG may occur in the absence of an oxidative environment. The lack of the \(\
u\) (S=O) mode in COST-Jet-treated samples suggested that in order to achieve the same biological responses, there must be another mechanism of oxidative stress that is unique to the COST-Jet source. The Raman spectra showed the formation of GSSG. The disulfide bond would form in a reaction between the glutathione radical and GSH. Both the sulfenic modification and glutathioneylation (a disulfide bond between GSH and another protein) were shown by others to adversely impact Jurkat cells [41]. H\({}_{2}\)O\({}_{2}\) added exogenously (at 200 \(\mu\)M) led to the irreversible oxidation of GSH and other proteins in the antioxidant systems that led to cellular arrest in Jurkat cells. The observed GSH modifications from nspDBD and COST-Jet treatments showed that there was the potential to induce these reactions in cell-associated GSH. Therefore, while the biological endpoint post plasma treatment was similar, the protein modifications and mechanisms for oxidative stress might be different between the two plasma sources. Next, we assessed if mock treatment-induced modifications were distinguishable from plasma treatment. We exogenously added the concentrations of RONS, shown in Table 2, to solutions of GSH in DI water.