Preparation, characterization, antifungal activity, and mechanism of chitosan/TiO 2 hybrid film against bipolaris maydis

A chitosan/TiO 2 hybrid film, as a powerful antifungal material for controlling southern corn leaf blight, which is caused by the fungus Bipolaris maydis ( B. maydis ), was prepared and characterized. Its antifungal activity toward B. maydis was studied, and the experimental results indicate that it had multiple attractive antifungal properties as follows: (1) it displayed strong antifungal activity against B. maydis , with an inhibition ratio of 100% under both visible‐light irradiation and in a dark environment; (2) it exhibited a superior antifungal efficacy of 100%, even after 4 h under the irradiation of visible light; and (3) its antifungal activity included the effect of hydroxyl radicals generated by the photocatalysis of TiO 2 . The antifungal mechanism was attributed to the action of a large amount of positive charges on the structure of the hybrid film, which interacted with the negative charges from the cell and finally resulted in the inactivation of B. maydis . © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013