Bacterial sterilization using Dielectric barrier discharge plasma in atmospheric pressure

Abstract

Background: Surface decontamination is an important issue in different areas like medicine and food industry. Traditional methods of sterilization have disadvantages as thermal effect and producing toxic chemical residues. Surface sterilization by cold plasma has been notices recently. In this study the effect of exposure time and capacitance of storage capacitors on cold plasma was assessed. Materials and Methods: In this experimental study an applicable and outstanding device for surface sterilization is presented. The dielectric barrier discharge (DBD) is a low temperature plasma source that is created between two conductive electrodes connected to an AC power supply and at least one of DBD electrodes is covered by dielectric layer. Results: The results of DBD plasma treatment of E. coli show that complete sterilization is occurred only after 2 seconds of exposure time without any thermal effect and increasing the exposure time increases the inactivation effect of the cold plasma. On the other hand by increasing the capacitance of capacitors the sterilization effect is increased obviously. DBD plasma is generated at 10kV voltage and 20 kHz frequency. Conclusion: This fast non-thermal and non-destructive method could be useful for inactivation of bacteria and hospital infection agents.