Enhanced Microbial Decontamination Using Non-thermal Low Pressure Argon Plasma Jet

Area of Science:

• Plasma physics and chemistry
• Microbiology
• Biomedical engineering

Background:

• Atmospheric pressure plasma jets (APPJs) offer cost-effective, non-lethal microbial inactivation.
• APPJs generate reactive oxygen and nitrogen species (ROS/RNS) for antimicrobial effects.

Purpose of the Study:

• To design and evaluate an argon APPJ system for microbial cell disinfection.
• To investigate the impact of organic matter on plasma's antimicrobial efficacy.

Main Methods:

• An argon APPJ was generated using a metallic tube and sinusoidal voltage (8-25 kHz).
• Microbial cell suspensions were exposed to the cold plasma jet for varying intervals.
• The effect of organic matter in the exposure medium on plasma lethality was assessed.

Main Results:

• The APPJ achieved significant reductions in viable cell counts for E. coli (98.3%) and S. aureus (94.1%) within 30s.
• Plasma antimicrobial activity was notably reduced in the presence of organic matter compared to water.
• Decimal Reduction Times (D-values) varied significantly based on microbial species and medium composition.

Conclusions:

• The developed argon APPJ system demonstrates effective disinfection capabilities against various microbes.
• Organic matter significantly diminishes the plasma's antimicrobial potency.
• APPJ technology presents a promising strategy for combating infections, particularly those caused by antibiotic-resistant pathogens.