Cold atmospheric plasma analysis for inactivation of bacterial endospores

Abstract

In space research extra-terrestrial bodies have to be protected from possible contaminations by terrestrial microorganisms. A newly developed plasma afterglow circulation apparatus is presented as a useful sterilization method for spacecraft equipment. The apparatus uses a surface micro-discharge (SMD) to create cold atmospheric plasma (CAP) and operates with ambient air and a relative humidity up to ~ 90 %. Microbiological investigations were executed to test the inactivation efficiency of the apparatus for different treatment volumes. Contact angle and XPS measurements were performed with different materials to test the material compatibility of the plasma treatment. In addition, the composition of the afterglow was analyzed for different humidity conditions and plasma parameters using Fourier Transformation Infrared (FTIR) and UV spectroscopy. The study improves the understanding of the processes which are involved in the inactivation of microorganisms and in the composition of the afterglow plasma. We will give an overview on the status of the plasma decontamination project funded by the Bavarian Ministry of Economics.