Enhancement of hydrogen peroxide production from an atmospheric pressure argon plasma jet and implications to the antibacterial activity of plasma activated water

Abstract

We explore how to configure an argon atmospheric-pressure plasma jet for enhancing its production of hydrogen peroxide (H2O2) in deionised water (DIW). The plasma jet consists of a quartz tube of 1.5 mm inner diameter and 3 mm outer diameter, with an upstream internal needle electrode (within the tube) and a downstream external cylindrical electrode (surrounding the tube). The plasma is operated by purging argon through the glass tube and applying a sinusoidal AC voltage to the internal needle electrode at 10 kV (peak–peak) with a frequency of 23.5 kHz. We study how the following operational parameters influence the production rate of H2O2 in water: tube length, inter-electrode separation distance, distance of the ground electrode from the tube orifice, distance between tube orifice and the DIW, argon flow rate and treatment time. By examining the electrical and optical properties of the plasma jet, we determine how the above operational parameters influence the major plasma processes that promote H2O2 generation through electron-induced dissociation reactions and UV photolysis within the plasma core and in the plasma afterglow; but with a caveat being that these processes are highly dependent on the water vapour content from the argon gas supply and ambient environment. We then demonstrate how the synergistic action between H2O2 and other plasma generated molecules at a plasma induced low pH in the DIW is highly effective at decontaminating common wound pathogens Gram-positive Staphylococus aureus and Gram-negative Pseudomonas aeruginosa. The information presented in this study is relevant in the design of medical plasma devices where production of plasma reactive species such as H2O2 at physiologically useful concentrations is needed to help realise the full clinical potential of the technology.

Recent Progress in Applications of Non-Thermal Plasma for Water Purification, Bio-Sterilization, and Decontamination

“…In this regard, Reuter et al [60] and Ito et al [61] described the control of RONS production in liquid by NTAPP with different shielding gases. Ghimire et al [62,63] discussed the variation of RONS with the gap distance, electrode separation, and plasma propagation length. Yue et al [64] and Lamichhane et al [31] studied the effects of working gas on the concentration of RONS.…”

Low-Temperature Plasma-Assisted Nitrogen Fixation for Corn Plant Growth and Development

“…The plasma includes OH radicals, which produce OES peaks at 306-310 nm due to the [49,50]. In addition, intense OES peaks are assigned to the nitrogen second positive system (N 2 SPS) at 311-380 nm, which corresponds to the N 2 (C 3 ∏ g −B 3 ∏ g ) transition [49,51,52], and the first negative system of nitrogen (N 2 FNS) at 380-420 nm, which corresponds to the N + 2 (B 2 ∑ + u −X 2 ∑ + u ) transition [53,54]. Weak emission signals produced by NO γ (200-280 nm), atomic oxygen (777 and 845 nm), and atomic nitrogen (742, 822, and 868 nm) are also apparent in the insects of Figure 2d.…”

“…During plasma discharge, numerous RONS are generated and delivered to the target liquid. OES is one of the best and easiest methods for monitoring the generation of these species in the gas phase [54]. Similarly, OES was carried out on the plasma using a spectrometer (HR4000+CG-UV-NIR, Ocean Optics, Inc., Orlando, FL, USA) and a 400 mm diameter optical fiber.…”

Cold Plasma Generation of Peracetic Acid for Antimicrobial Applications

“…[1][2][3] Even though the chemistry of PAW can be varied in a number of ways, its main antimicrobial effects are usually mainly attributed to the combination of hydrogen peroxide (H 2 O 2 ) and nitrogen oxide species that reduce the pH of water. [4][5][6][7] The reason for this is that most plasma treatments produce a much higher concentration of H 2 O 2 compared to other generated reactive species, and they also produce peroxynitrous acid that decreases the water's pH. Acidification is known to enhance the antibacterial property of H 2 O 2 .…”

“…Acidification is known to enhance the antibacterial property of H 2 O 2 . [1][2][3][4][5] The use of PAW as an antibacterial agent has been investigated across several industries, including medicine, 2,8,9 agriculture, 10,11 and food. 3 PAW has been shown to have a high level of antibacterial efficacy in the above applications, including against antibiotic-resistant bacteria.…”