Magnetic field enhanced cold plasma sterilization

Cold plasma sterilization offers an efficient way to sterilize medical components and instruments. This paper reports using a magnetized plasma to realize low-temperature sterilization. A radio frequency dielectric barrier discharge is created in a quartz tube using a mixture of argon and oxygen gas. A uniform amount of Escherichia coli is applied onto glass slides and exposed to the plasma afterglow at different pressures with and without a magnetic field. Optical emission spectroscopy is used to identify the plasma species present. The magnetic field significantly promotes the intensity of the plasma and the sterilization efficiency. A process gas pressure of 100 mTorr presents the most effective treatment with a sterilization time less than one minute and sample temperature below 32 degrees C.