A composite film based on a vanadium-substituted molybdophosphate H-6[PMo9V3O40] (PMo9V3) decorated by platinum nanoparticles (Pt) has been prepared by the layer-by-layer self-assembly method. The growth process of the composite film was monitored by UV-vis spectroscopy, and the elemental composition and surface morphology were surveyed by X-ray photoelectron spectra (XPS) and atomic force microscopy (AFM), respectively. Comparative experiments revealed that the electrocatalytic efficiency and amperometric response of this composite film toward oxidation of dopamine at physiological conditions were markedly enhanced by synergistic contributions of PMo9V3 and Pt. The sensing performance for dopamine detection was investigated in detail. At physiological conditions, the composite film exhibited high sensitivity of 1.2 mu M/mu A dopamine, fast response time (<1 s), low detection limit (similar to 1.3 x 10(-7) M), and a wide linear range from 4.2 x 10(-7) to 1.3 x 10(-3) M toward amperometric sensing of dopamine, as well as no interference from the common interfering species such as ascorbic acid, glucose, uric acid and L-cysteine. (C) 2013 Elsevier Ltd. All rights reserved.