| AVS 65th International Symposium & Exhibition | |
| Plasma Science and Technology Division | Tuesday Sessions |
| Session PS+PB-TuM |
| Session: | Plasma Medicine |
| Presenter: | Ek Adhikari, University of Notre Dame |
| Authors: | E.R. Adhikari, University of Notre Dame V. Samara, University of Notre Dame S. Ptasinska, University of Notre Dame |
| Correspondent: | Click to Email |
Recently, we performed in-situ measurements of reactive oxygen species of a helium atmospheric pressure plasma jet (APPJ) using an acidified ferrous sulfate solution (Fricke) as a sample. The total yield of reactive species reached to or originated in the solution corresponds to the amount of the yield of Fe3+ from reactions that transform Fe2+ into Fe3+ during plasma irradiation. The measurements indicated that the number of reactive species formed in the plasma jet is proportional to the applied pulse voltage and repetition frequency. However, there is a decrease in the yield of Fe3+ per pulse for an increase in the frequency. For higher frequencies, there is not enough time to complete all reactions before the next pulse arrives to the sample. Whereas, for lower frequencies, this yield is higher due to the relatively longer time period necessary for reactions to complete. Further, the flow rate of feed gas and treatment distance, which is the distance between the sample and glass capillary, have a minor effect on the formation of reactive species, but the yield of Fe3+ gradually decreases for a treatment distance longer than 20 mm. Moreover, we calculated the yield of Fe3+ in a very short time (equivalent to time period used in the experiment), and compared with the experimental results. The yield of Fe3+ formed within 15 s of plasma irradiation was also compared with the fractions of plasma induced DNA damage level under similar experimental conditions.