Abstract
Cold atmospheric pressure sterilization is one of the nominated and efficient techniques to prevent the spread of diseases. Reactive species such as O and OH and other radicals play a major role in the mechanism of plasma sterilization. Therefore, in this work, oxygen was mixed with different parentage from (0.2 to 1.2%) to argon to enhance the generation of the reactive species and increase the argon atmospheric pressure plasma sterilization efficacy. The emission spectra from the jet increase the radicle line intensities by increasing the percentage admixture of O-2 with the argon gas to reach a maximum power at 0.8; then, it gradually decreases with a higher O-2 percentage. The OH band intensity decreases with increasing the admixture of O-2. The jet with different O-2 percentages was tested against Gram-positive S. epidermidis, which is the causal agent of nosocomial infections. The maximum reduction in colony-forming units (CFU) was observed at 0.2% O-2. No bacterial growth was observed at the later concentration applied for 8 min and the same case was detected at 0.4% O-2 applied to 16 min.