Characteristics of DC gas-liquid phase atmospheric-pressure plasma and bacteria inactivation mechanism

Jie Shen, Qiang Sun, Zelong Zhang, Cheng Cheng*, Yan Lan, Hao Zhang, Zimu Xu, Ying Zhao, Weidong Xia*, Paul K. Chu*

*Corresponding author for this work

    Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

    74 Citations (Scopus)

    Abstract

    A direct current (DC) gas-liquid phase atmospheric-pressure argon (Ar) plasma is used to inactivate Staphylococcus aureus suspended in the liquid. The characteristics of the gas-liquid plasma such as gas temperature, electron excitation temperature, and electron density are investigated by optical emission spectroscopy (OES). Direct plasma treatment for 40 min results in more than 2.0-log cell reduction. The emission spectra obtained from the gas-liquid phase plasma show the presence of hydroxyl radicals and atomic oxygen which give rise to effective inactivation of microorganisms. The energetic particles generated from the plasma tend to induce chemical effects such as formation of hydroxyl and hydrogen peroxide and reduced pH. The water sample after plasma treatment retains the inactivation ability for a long time and the germicidal effects arise from residual H2O2 and acidic pH. These effects have potential applications in plasma biomedicine and water purification. Atmospheric pressure cold plasmas have been thought to be a promising candidate for biomedical applications. In some cases, the plasmas contact living tissues where a gas-liquid environment forms between the body fluid and plasmas. The physical characteristics of plasmas or inactivation of bacteria in solutions are important. A gas-liquid phase Ar plasma is generated in a quartz glass tube immersed in water. Characteristics of the plasma, active species formation, and bacterial effects are investigated systematically. Understanding the characteristics and inactivation mechanism, we can use this technology for biomedical application or water purification effectively.
    Original languageEnglish
    Pages (from-to)252-259
    JournalPlasma Processes and Polymers
    Volume12
    Issue number3
    Online published22 Dec 2014
    DOIs
    Publication statusPublished - Mar 2015

    Research Keywords

    • bacteria inactivation
    • gas-liquid phase atmospheric pressure plasma
    • plasma process in liquid
    • reactive species

    Fingerprint

    Dive into the research topics of 'Characteristics of DC gas-liquid phase atmospheric-pressure plasma and bacteria inactivation mechanism'. Together they form a unique fingerprint.

    Cite this