Effectiveness of Using HHO Gas for PBII Treatment in Sterilizing Escherichia Coli

— Plasma-based ion implantation (PBII) is a surface modification technique that uses a negative high-voltage pulse in plasma to implant ions uniformly onto a sample. This technique is performed by narrowing the width of the ion sheath formed near the sample and aligning the shape of the sheath closely to the sample, particularly for complexly shaped samples. Our investigation focuses on the application potential of PBII in sterilizing microorganisms. In particular, we aimed to determine the most suitable gas species for sterilization using PBII on Escherichia coli, a type of microorganism that can contaminate food. Our findings demonstrate that nitrogen or oxygen gas could increase the sterilization effect with an increase in applied voltage. The provided conductive stainless-steel is used as the Petri dish for sample fixation. By contrast, sterilization becomes more effective when HHO gas, which is produced by water electrolysis and is non-hazardous compared with peroxide gas, is utilized compared with other gases, even at a low applied voltage of −2 kV. Therefore, the use of HHO gas in PBII could enable milder sterilization conditions than previously attainable when sterilizing foodstuffs.