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Title: Protein destruction by atmospheric pressure glow discharges

Abstract

It is well established that atmospheric pressure glow discharges are capable of bacterial inactivation. Much less known is their ability to destruct infectious proteins, even though surgical instruments are often contaminated by both bacteria and proteinaceous matters. In this letter, the authors present a study of protein destruction using a low-temperature atmospheric dielectric-barrier discharge jet. Clear evidences of protein removal are presented with data of several complimentary experiments using scanning electron microscopy, electron dispersive x-ray analysis, electrophoresis, laser-induced fluorescence microscopy, and protein reduction kinetics. Considerable degradation is observed of protein fragments that remain on their substrate surface after plasma treatment.

Authors:
; ; ;  [1];  [2];  [2]
  1. Department of Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)
  2. (United Kingdom)
Publication Date:
OSTI Identifier:
20883259
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 90; Journal Issue: 1; Other Information: DOI: 10.1063/1.2410219; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS; ATMOSPHERIC PRESSURE; BACTERIA; BIOLOGICAL RADIATION EFFECTS; CHEMICAL ANALYSIS; DIELECTRIC MATERIALS; ELECTROPHORESIS; FLUORESCENCE; GLOW DISCHARGES; OPTICAL MICROSCOPY; PLASMA JETS; PROTEINS; SCANNING ELECTRON MICROSCOPY; X RADIATION

Citation Formats

Deng, X. T., Shi, J. J., Chen, H. L., Kong, M. G., MRC Toxicology Unit, University of Leicester, Leicester, Leicestershire LE1 9HN, and Department of Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU. Protein destruction by atmospheric pressure glow discharges. United States: N. p., 2007. Web. doi:10.1063/1.2410219.
Deng, X. T., Shi, J. J., Chen, H. L., Kong, M. G., MRC Toxicology Unit, University of Leicester, Leicester, Leicestershire LE1 9HN, & Department of Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU. Protein destruction by atmospheric pressure glow discharges. United States. doi:10.1063/1.2410219.
Deng, X. T., Shi, J. J., Chen, H. L., Kong, M. G., MRC Toxicology Unit, University of Leicester, Leicester, Leicestershire LE1 9HN, and Department of Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU. Mon . "Protein destruction by atmospheric pressure glow discharges". United States. doi:10.1063/1.2410219.
@article{osti_20883259,
title = {Protein destruction by atmospheric pressure glow discharges},
author = {Deng, X. T. and Shi, J. J. and Chen, H. L. and Kong, M. G. and MRC Toxicology Unit, University of Leicester, Leicester, Leicestershire LE1 9HN and Department of Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU},
abstractNote = {It is well established that atmospheric pressure glow discharges are capable of bacterial inactivation. Much less known is their ability to destruct infectious proteins, even though surgical instruments are often contaminated by both bacteria and proteinaceous matters. In this letter, the authors present a study of protein destruction using a low-temperature atmospheric dielectric-barrier discharge jet. Clear evidences of protein removal are presented with data of several complimentary experiments using scanning electron microscopy, electron dispersive x-ray analysis, electrophoresis, laser-induced fluorescence microscopy, and protein reduction kinetics. Considerable degradation is observed of protein fragments that remain on their substrate surface after plasma treatment.},
doi = {10.1063/1.2410219},
journal = {Applied Physics Letters},
number = 1,
volume = 90,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Biological sterilization represents one of the most exciting applications of atmospheric pressure glow discharges (APGD). Despite the fact that surgical instruments are contaminated by both microorganisms and proteinaceous matters, sterilization effects of APGD have so far been studied almost exclusively for microbial inactivation. This work presents the results of a detailed investigation of the capability of a helium-oxygen APGD to inactivate proteins deposited on stainless-steel surfaces. Using a laser-induced fluorescence technique for surface protein measurement, a maximum protein reduction of 4.5 logs is achieved by varying the amount of the oxygen admixture into the background helium gas. This corresponds tomore » a minimum surface protein of 0.36 femtomole/mm{sup 2}. It is found that plasma reduction of surface-borne protein is through protein destruction and degradation, and that its typically biphasic reduction kinetics is influenced largely by the thickness profile of the surface protein. Also presented is a complementary study of possible APGD protein inactivation mechanisms. By interplaying the protein inactivation kinetics with optical emission spectroscopy, it is shown that the main protein-destructing agents are excited atomic oxygen (via the 777 and 844 nm emission channels) and excited nitride oxide (via the 226, 236, and 246 nm emission channels). It is also demonstrated that the most effective protein reduction is achieved possibly through a synergistic effect between atomic oxygen and nitride oxide. This study is a useful step toward a full confirmation of the efficacy of APGD as a sterilization technology for surgical instruments contaminated by prion proteins.« less
  • Reliable applications of atmospheric-pressure glow discharges (APGDs) depend critically on their plasma stability. A common technique of ensuring APGD stability is to keep their operation well within their stability range by decreasing their discharge current. However, this reduces the achievable densities of the reactive plasma species and, thereby, compromises the application efficiency. In this letter, the use of high excitation frequencies in radio-frequency APGD is shown to substantially expand their stability range. It is also demonstrated that high-frequency operation introduces an added benefit of higher electron energy and greater electron density, thus enabling more abundant reactive plasma species and improvedmore » application efficiency.« less
  • Discharge modes, {alpha} and {gamma}, of a radio-frequency helium capacitively coupled discharge at atmospheric pressure were investigated with the discharge gap distance between electrodes varied from 1 to 5 mm. As similarly observed in other experiments, the {alpha} and {gamma} mode and the {alpha}-{gamma} mode transition were observed with large drops in the voltage (310-179 V) and the phase angle between the voltage and current (54 deg. -18 deg. ), and a contraction of the plasma volume (8.5-0.17 cm{sup 3}, at 3 mm gap distance). The discharge voltage where the {alpha}-{gamma} mode transition occurred versus the gap distance showed amore » similar behavior with the Paschen curve for a gas breakdown. Depending on the gap distance, normal and abnormal glow regimes were observed in the {alpha}mode. At 1 and 2 mm, the {alpha} mode remained in the abnormal glow discharge until the {alpha}-{gamma} mode transition occurred as the discharge current increases. At 3 mm, however, the {alpha} mode was excited as a normal glow discharge with a constant current density (17 mA/cm{sup 2}) but it became an abnormal glow discharge as the current increased. At 4 mm, the {alpha} mode was sustained as a normal glow discharge, then the transition to the {gamma} mode occurred. Using a simple resistor-capacitor circuit model and a {alpha} sheath breakdown model, the discharge modes and the mode transition properties were studied.« less
  • In this letter, an induced gas discharge approach is proposed and described in detail for obtaining a uniform atmospheric-pressure glow discharge with air in a {gamma} mode using water-cooled, bare metal electrodes driven by radio-frequency (13.56 MHz) power supply. A preliminary study on the discharge characteristics of the air glow discharge is also presented in this study. With this induced gas discharge approach, radio-frequency, atmospheric-pressure glow discharges using bare metal electrodes with other gases which cannot be ignited directly as the plasma working gas, such as nitrogen, oxygen, etc., can also be obtained.
  • In this letter, atmospheric-pressure glow discharges in {gamma} mode with argon/nitrogen as the plasma-forming gas using water-cooled, bare copper electrodes driven by radio-frequency power supply at 13.56 MHz are achieved. The preliminary studies on the discharge characteristics show that, induced by the {alpha}-{gamma} coexisting mode or {gamma} mode discharge of argon, argon-nitrogen mixture with any mixing ratios, even pure nitrogen, can be employed to generate the stable {gamma} mode radio-frequency, atmospheric-pressure glow discharges and the discharge voltage rises with increasing the fraction of nitrogen in the argon-nitrogen mixture for a constant total gas flow rate.