This study aimed to analyse the efficacy of a new cold plasma device adapted for treatment with a low power consumption . We tested the reduction of bacterial cells in biofilms of E. coli, S. aureus and P. aeruginosa. . The results show significant differences between bacterial cells, suggesting that Gramme-positive S. aureus is less susceptible to plasma treatment than Gramme-negative E. coli and P. aeruginosa. Increasing the exposure time and decreasing the distance decreases the number of cells in the biofilm. However, the combination of close distance and long exposure time resulted in synergistic effects. We demonstrated a reduction of up to 6.6 log CFU cm2 for E. coli at 1 mm and an exposure time of 60 seconds. All these indicate that the new cold plasma jet device can be an important key to ensuring hygiene and numerous applications in medicine and engineering are possible.
Keywords: Cold plasma; bacterial reduction; biofilms; treatment time and distance.