Plasma flux-dependent lipid A deactivation

Hung Wen Chang, Cheng Che Hsu, Musahid Ahmed, Suet Yi Liu, Yigang Fang, Joonil Seog, Gottlieb S. Oehrlein, David B. Graves

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


This paper reports the influence of gas plasma flux on endotoxin lipid A film deactivation. To study the effect of the flux magnitude of reactive species, a modified low-pressure inductively coupled plasma (ICP) with O radical flux ∼1016cm-2s-1 was used. After ICP exposures, it was observed that while the Fourier transform infrared absorbance of fatty chains responsible for the toxicity drops by 80% through the film, no obvious film endotoxin deactivation is seen. This is in contrast to that previously observed under low flux exposure conducted in a vacuum beam system: near-surface only loss of fatty chains led to significant film deactivation. Secondary ion mass spectrometry characterization of changes at the film surface did not appear to correlate with the degree of deactivation. Lipid A films need to be nearly completely removed in order to detect significant deactivation under high flux conditions. Additional high reactive species flux experiments were conducted using an atmospheric pressure helium plasma jet and a UV/ozone device. Exposure of lipid A films to reactive species with these devices showed similar deactivation behaviour. The causes for the difference between low and high flux exposures may be due to the nature of near-surface structural modifications as a function of the rate of film removal.

Original languageEnglish (US)
Article number224015
JournalJournal of Physics D: Applied Physics
Issue number22
StatePublished - Jun 4 2014
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Acoustics and Ultrasonics
  • Surfaces, Coatings and Films


  • ICP
  • endotoxin
  • lipid A deactivation
  • plasma flux


Dive into the research topics of 'Plasma flux-dependent lipid A deactivation'. Together they form a unique fingerprint.

Cite this