Inactivation of bacteria by a homemade cold atmospheric pressure plasma jet

• Main Authors: Chieh-Fu Wang, 王介甫
• Other Authors: Ming-Chen Wang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/03772888154463913293

碩士 === 中原大學 === 生物醫學工程研究所 === 101 === This study is using the damping-like factor generator to coupling high voltage coil, and combines the cold atmospheric pressure plasma-jet device for sterilization. The applied voltage and the discharge current of a damping waveform is respective 10.2 kV and 0.348 A, the frequency is 190 kHz, the total power of plasma-jet is 17.74 W, the maximum plasma length and applied temperature is respective 15 mm and 31oC. Diagnose the active species in the helium plasma by optical emission spectroscopy (OES). The emission spectrum of helium can be observed at 391.32, 668.45, 706.21 and 728.16 nm; The spectrum of oxygen can be observed at 777.32, 845.74 and 927.28 nm. Samples of E. coli and E. faecalis are selected for this study. The largest area of the plasma sterilization reach to 408 mm2; the quantitative analysis result of E. coli and E. faecalis sterilization shows that the D-value (90% sterilization) is respective 120 seconds and 15 min. The mechanisms of bacteria inactivation are investigated by FE-SEM, Bradford protein assay and TBARS assay. SEM of the bacteria after plasma treatment can find the bacteria surface has deformation, fracture and shrinkage. Bradford protein assay shows the protein leakage is increase with plasma treatment time increase, but if the treatment time is over 10 min, the protein leakage is decrease. TBARS assay shows amount of MDA is increase with plasma treatment. In conclusion, this study has successfully developed a homemade cold atmospheric pressure plasma jet, and possesses sterilization result.