Journal article
Gas flow dependence for plasma-needle disinfection of S. mutans bacteria
Journal of physics. D, Applied physics, Vol.39(16), pp.3479-3486
08/21/2006
DOI: 10.1088/0022-3727/39/16/S05
Abstract
The role of gas flow and transport mechanisms are studied for a small low-power impinging jet of weakly-ionized helium at atmospheric pressure. This plasma needle produces a non-thermal glow discharge plasma that kills bacteria. A culture of Streptococcus mutans (S. mutans) was plated onto the surface of agar, and spots on this surface were then treated with plasma. Afterwards, the sample was incubated and then imaged. These images, which serve as a biological diagnostic for characterizing the plasma, show a distinctive spatial pattern for killing that depends on the gas flow rate. As the flow is increased, the killing pattern varies from a solid circle to a ring. Images of the glow reveal that the spatial distribution of energetic electrons corresponds to the observed killing pattern. This suggests that a bactericidal species is generated in the gas phase by energetic electrons less than a millimetre from the sample surface. Mixing of air into the helium plasma is required to generate the observed O and OH radicals in the flowing plasma. Hydrodynamic processes involved in this mixing are buoyancy, diffusion and turbulence.
Details
- Title: Subtitle
- Gas flow dependence for plasma-needle disinfection of S. mutans bacteria
- Creators
- J Goree - University of IowaBin Liu - University of IowaDavid Drake - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of physics. D, Applied physics, Vol.39(16), pp.3479-3486
- DOI
- 10.1088/0022-3727/39/16/S05
- ISSN
- 0022-3727
- eISSN
- 1361-6463
- Language
- English
- Date published
- 08/21/2006
- Academic Unit
- Physics and Astronomy; Dental Research; Mechanical Engineering; Endodontics
- Record Identifier
- 9984200054802771
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