Naslov
Characterization of oxygen plasma during degradation of Escherichia coli by optical emission spectroscopy

Autori
Vujošević, Danijela ; Junkar, Ita ; Krstulović, Nikša ; Milošević, Slobodan ; Mozetič, Miran ; Cvelbar , Uroš

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Zbornik Povzetkov 14. Mednarodni znanstveni sestanek Vakuumska znanost in tehnika / Šetina, Janez ; Kovač, Janez - Ljubljana : Društvo za vakuumsko tehniko Slovenije, 2007, 12-12

Skup
14. Mednarodni znanstveni sestanek Vakuumska znanost in tehnika

Mjesto i datum
Bled, Slovenija, 01.06.2007

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
oxygen plasma; plasma characterization; optical emission spectroscopy; Langmuir probe; catalytic probe; bacteria; sterilization; Escherichia coli

Sažetak
Optical emission spectroscopy was applied for plasma characterization during sterilization of substrates contaminated with bacteria. The amount of 1010/ml cells os Escherichia coli was carefully applied to glass substrates and exposed to oxygen plasma glow discharge at different pressures between 30 Pa and 200 Pa. Plasma was created in a glass discharge tube by an inductively coupled radiofrequency (RF) generator at the frequency of 27.12. MHz and output power of about 250 W. The electron temperature and plasma density were estimated with a double Langmuir probe. They were between 3-5 eV and 2-35x1015 m-3. Density of neutral oxygen atoms was measured with a catalytic probe, and was between 2 and 6x1021 m-3. Optical emission spectroscopy was performed with a low resolution spectrometer. The emission from carbon monoxide and nitrogen molecules was used to monitor the evolution of bacteria degradation. Both signals expressed a well defined maximum corresponding to peak erosion of bacteria by plasma radicals. As the sterilization was accomplished, both CO and N2 lines fell below the detection limit of the spectrometer. The bacteria degradation was also monitored by Scanning Electron Microscope (SEM) and culturing. The SEM images corresponded well with the evolution of CO and N2 lines so the optical emission spectroscopy was found a reliable tool for monitoring the sterilization process.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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