Ordered mesoporous TiO(2) was synthesized using the combined assembly of soft and hard chemistries method and deposited as a film coating on a microcantilever sensor array along with two other types of TiO(2) film: one from nanoparticles and one prepared via a sol-gel reaction. After loading methylene blue molecules on the TiO(2) films, the films were exposed to ultraviolet radiation. The photocatalytic decomposition of methylene blue was monitored by measuring changes in the resonance frequency of each cantilever. The mesoporous TiO(2) film showed higher photocatalytic activity than conventional TiO(2) films fabricated from nanoparticles or via a sol-gel reaction; this difference is attributed to the purely anatase crystalline morphology of the mesoporous TiO(2) film as well as its well-organized pore structure. The three-dimensionally interconnected pore network facilitates the diffusion of methylene blue molecules to the photocatalytically active sites of the mesoporous TiO(2).