Bacteria Inactivation Using DBD Plasma Jet in Atmospheric Pressure Argon

Abstract

A coaxial dielectric barrier discharge plasma jet was designed, which can be operated in atmospheric pressure argon under an intermediate frequency sinusoidal resonant power supply, and an atmospheric pressure glow-like discharge was achieved. Two kinds of typical bacteria, i.e., the Staphylococcus aureus (S. aureus) and Escherichia coil (E. coil), were employed to study the bacterial inactivation mechanism by means of the non-thermal plasma. The killing log value (KLV) of S. aureus reached up to 5.38 with a treatment time of 90 s and that of E. coil up to 5.36 with 60 s, respectively. According to the argon emission spectra of the plasma jet and the scanning electron microscope (SEM) images of the two bacteria before and after the plasma treatment, it is concluded that the reactive species in the argon plasma played a major role in the bacterial inactivation, while the heat, electric field and UV photons had little effect.

Inactivation of Biofilms Using a Low Power Atmospheric Pressure Argon Plasma Jet; the Role of Entrained Nitrogen

“…It is stated in literature that UV can inactivate cells if the dose is high enough and the wavelength is within the “most germicidal range” (from 220 to 280 nm). However, the spectrum of the afterglow plasma does not show significant UV emission below 285 nm.…”

“…A careful inspection reveals that very weak lines (778 and 845 nm) of OI are present in the near IR region. It is stated in literature [11,[21][22][23] that UV can inactivate cells if the dose is high enough and the wavelength is within the ''most germicidal range'' (from 220 to 280 nm). However, the spectrum of the afterglow plasma does not show significant UV emission below 285 nm.…”

Filamentary and Homogeneous Modes of Dielectric Barrier Discharge (DBD) in Air: Investigation through Plasma Characterization and Simulation of Surface Irradiation

“…DBDs are operated in wide range of pressures1, 2 in different gases3–5 and therefore they are attractive for diversified industrial applications. These low‐temperature discharges, when operated at atmospheric pressure, are suitable for the treatment of materials which are sensitive to temperature and pressure, like thermolabile materials and biological substrates 6, 7…”

Sterilization of Streptococcus pyogenes by afterglow dielectric barrier discharge using O2 and CO2 working gases

“…; and neutral, positive and negative hydroxyl (OH, OH + , OH − ), dependent upon the working gases. In atmospheric-pressure plasma, most of the generated UV radiation is absorbed by air molecules and does not play a significant part in disinfection [20,21]. In atmospheric-pressure DBD using oxygen gas, O 3 and reactive oxygen spices (ROS) such as O, O 2 (a 1 g ), O + , O − , O 2 − , and O 2 + are generated and have effective bactericidal properties.…”