Cold Atmospheric Argon Plasma Jet Research Articles

Plasma medicine and wound management: Evaluation of the antibacterial efficacy of a medically certified cold atmospheric argon plasma jet

Objectives: A major problem for wound healing is contamination with bacteria, often resulting in biofilm formation and wound infection, which, in turn, needs immediate intervention such as surgical debridement and through irrigation. A topical treatment with cold atmospheric pressure plasma (CAP) for wound disinfection may present an alternative and less painful approach.Methods: This study investigated the antibacterial effects of a cold atmospheric pressure argon plasma jet (kINPen® MED) as a CAP source, using the three-dimensional Staphylococcus aureus immunocompetent biofilm system hpBIOM in addition to a standard planktonic test. Furthermore, skin cell compatibility was evaluated using a keratinocyte (HaCat) model.Results: CAP treatment (0–240 s) followed by incubation (15, 120 min) within the CAP-treated media showed slight bactericidal efficacy under planktonic conditions but no effect on biofilms. However, indirect CAP treatment of keratinocytes performed under the same conditions resulted in a significant decrease in metabolic activity. Short CAP treatment and exposure time (30 s; 15 min) induced a slight increase in the metabolic activity; however, longer treatments and/or exposure times led to pronounced reductions up to 100%. These effects could partially be reversed by addition of catalase, indicating a dominant role of CAP-generated hydrogen peroxide.Conclusions: These results indicate that plasma treatment does not lead to the desired disinfection or significant reduction in the bacterial burden of Staphylococcus aureus in a wet milieu or in biofilms. Thus, treatment with CAP could not be recommended as a single anti-bacterial therapy for wounds but could be used to support standard treatments.

Experimental Studies on Physicochemical Parameters of Water Samples before and after Treatment with a Cold Atmospheric Plasma Jet and its Optical Characterization

Cold plasma-liquid interaction becomes a growing interdisciplinary area of research involving plasma physics, fluid science, and chemistry. Plasma-liquid interaction has gained more interest over the last many years due to its potential applications in different fields. Cold atmospheric plasma jet is an emerging technology for surface drinking water treatment to improve quality and surface modification that is chemical-free and eco-friendly. Cold plasma treatment of water samples results in changes in turbidity, pH, and conductivity and in the formation of reactive oxygen and nitrogen species (RONS). As a result, plasma-activated water has a different chemical composition than water and can serve as an alternative technique for microbial disinfection. CAPJ has been generated by a high voltage 5 kV and a high frequency 19.56 kHz power supply. The discharge has been characterized by an optical method. To characterize the cold atmospheric pressure argon plasma jet, discharge plume temperature, and electron rotational and vibrational temperature have been determined. Cold atmospheric argon plasma jet produced at atmospheric condition contains high energetic electrons, ions, UV radiation, reactive oxygen, and nitrogen species named as cold plasma which has a wide range of applications in the biomedical industry, as well as in water treatment. Nowadays, researches have been carried out on ozonation through plasma jet interaction with surface drinking water. In this paper, we compare the change in physical and chemical parameters of surface water used for drinking purposes. The significant change in the physical parameters such as pH, turbidity, and electrical conductivity was studied. In addition, the significant changes in the concentration and absorbance of nitrate, ferrous, and chromium ions with respect to treatment time were studied. Our results showed that plasma jet interaction with surface drinking water samples can be useful for the improvement of water quality and an indicator for which reactive species play an important role in plasma sterilization.

Cold atmospheric argon plasma jet source and its application for bacterial inactivation

In this work, the efficiency of inactivation of a cold argon plasma jet at atmospheric pressure (APPJ) on the basis of a low-current spark discharge into microorganisms with different characteristics of the cell walls was evaluated. Gram-negative bacteria Escherichia coli M17, gram-positive bacteria Bacillus subtilis 534 and Bacillus cereus IP 5832, and the yeast Saccharomyces cerevisiae were seeded on cultured Petri dishes. A plasma jet with an average power of 0.85 W and a flow rate of argon of 6.7 l/min was directed perpendicular to the Petri dishes with agar. The distance to the agar varied from 0.5 to 3 cm, and the treatment time varied from 5 to 300 s. The efficiency of inactivation was assessed by measuring the area of inactivation zones (where there was no growth of microorganisms). It was shown that gram-negative bacteria E. coli M17 is most susceptible to exposure to the plasma jet, and gram-positive bacteria B. cereus IP 5832 and yeast S. cerevisiae are most stable. It is established that an increase in the treatment time of plasma jets of a low-current spark allows effective inactivation of microorganisms over a much larger area.

Degradation of bromophenol blue molecule during argon plasma jet irradiation

The aim of this paper is to study degradation of a bromophenol blue molecule (C19H10Br4O5S) using direct irradiation of cold atmospheric argon plasma jet. The pH of the bromophenol blue solution has been measured as well as its absorbance spectra and conductivity before and after the irradiation of non-thermal plasma jet in various time durations. The results indicated that the lengths of conjugated systems in the molecular structure of bromophenol blue decreased, and that the bromophenol blue solution was decolorized as a result of the decomposition of bromophenol blue. This result shows that non-thermal plasma jet irradiation is capable of decomposing, and can also be used for water purification.

Effect of voltage shape of electrical power supply on radiation and density of a cold atmospheric argon plasma jet

در این مقاله به تولید جت پلاسمای سرد فشار اتمسفری گاز آرگون با استفاده از روش تخلیه سد دی‌الکتریک با سه منبع توان الکتریکی با ولتاژ سینوسی، پالسی و دندان‌اره‌ای در بسامد یکسان 8 کیلوهرتز پرداختیم. ابتدا ویژگی مدار الکترونیک مورد نظر را برای تولید ولتاژ فشار قوی با شکل ولتاژ خروجی سینوسی، پالسی و دندان‌اره‌ای توضیح می‌دهیم. سپس اثر شکل ولتاژ اعمالی در شکست الکتریکی گاز بررسی می‌کنیم. غلظت نسبی گونه‌های فعال شیمیایی از جمله اکسیژن، نیتروژن اتمی، رادیکال هیدروکسیل به وسیله بیناب نمایی گسیل نوری اندازه‌گیری شد. همچنین با استفاده از یک مدل ساده نشان دادیم زمان برخاست کم موجب افزایش چگالی الکترون می‌شود بنابراین با توان الکتریکی مصرفی پایین‌تر می‌توان یک پلاسمای سرد تولید کرد.

On the plasma chemistry of a cold atmospheric argon plasma jet with shielding gas device

A novel approach combining experimental and numerical methods for the study of reaction mechanisms in a cold atmospheric plasma jet is introduced. The jet is operated with a shielding gas device that produces a gas curtain of defined composition around the plasma plume. The shielding gas composition is varied from pure to pure .The density of metastable argon in the plasma plume was quantified using laser atom absorption spectroscopy. The density of long-living reactive oxygen and nitrogen species (RONS), namely , , , , and , was quantified in the downstream region of the jet in a multipass cell using Fourier-transform infrared spectroscopy (FTIR).The jet produces a turbulent flow field and features guided streamers propagating at several that follow the chaotic argon flow pattern, yielding a plasma plume with steep spatial gradients and a time dependence on the scale while the downstream chemistry unfolds within several seconds. The fast and highly localized electron impact reactions in the guided streamer head and the slower gas phase reactions of neutrals occurring in the plasma plume and experimental apparatus are therefore represented in two separate kinetic models. The first electron impact reaction kinetics model is correlated to the LAAS measurements and shows that in the guided streamer head primary reactive oxygen and nitrogen species are dominantly generated from . The second neutral species plug-flow model hence uses an source term as sole energy input and yields good agreement with the RONS measured by FTIR spectroscopy.