Highly effective large-area inactivation of B. subtilis spore using a planar dielectric barrier discharge jet with CF4/air mixture

In this paper, we demonstrate that, by adding a small amount of CF ₄ (2%) into a compressed-air planar dielectric barrier discharge (DBD), one can effectively inactivate a B. subtilis spore up to 50mmin width in the postdischarge jet region after ten passes of exposure of plasma plume (equivalent plasma exposure time of 1 s) for treatment distance of up to 14 mm for the spore concentration in the range of 10⁵?10⁷ CFU/mL. A possible mechanism is proposed, i.e., the chemically active F atoms and CF_n (n = 1? 3) are generated through the help of abundant excited nitrogen molecules in the postdischarge region.