Developing a Testing Method for Antimicrobial Efficacy on TiO2 Photocatalytic Products

TiO2 photocatalyst has been known to exhibit a notable disinfecting activity against a broad spectrum of microorganisms. A lot of commercial TiO2 photocatalyst products have been developed for antimicrobial purposes. However, a standard method has not yet been proposed for use in testing antimicrobial activity. In this study, we developed a TiO2 photocatalytic adhesion test method with film as the standard testing method for the evaluation of antimicrobial activity. This method was devised by modifying the previous antimicrobial products test method, which has been widely used, and considering the characteristics of TiO2 photocatalytic reaction. The apparatus for testing the antimicrobial activity was composed of a Black Light Blue (BLB) lamp as UV-A light source, a Petri dish as the cover material, and a polypropylene film as the adhesion film. The standard TiO2 photocatalyst sample, Degussa P25 TiO2-coated glass, could only be used once. The optimal initial concentration of the microorganism, proper light intensity, and light irradiation time were determined to be 10(6) CFU/mL, 1.0 mW/cm2, and 3 hr, respectively, for testing and evaluating antimicrobial activity on the TiO2 surface.

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