Microwave sterilization by the catalyst coated with metal thin film

We developed a novel sterilization method by which the microwave irradiation sterilizes Escherichia coli cells on a unique material of catalyst. The materials containing TiO/sub 2/ and SiO/sub 2/ were coated with several kinds of metals. The pellet coated with nanometer size metal had the porous structure and the phase of the structure kept anatase. We showed that the microwave irradiation completely sterilized all of the E. coli inside of the pellet, while UV irradiation sterilized only the surface of the pellet. The current results suggest that the active oxygen radical generated by irradiation of microwave plays an important role in sterilization of microorganisms.