Enhancing characteristics of a composite film by combination of vanadium-substituted molybdophosphate and platinum nanoparticles for an electrochemical sensor

A proposed electrochemical sensor has highly selective, sensitive, stable and fast determination of dopamine, as well as no interference from the common interfering species at an applied potential of 0.8V. A composite film based on a vanadium-substituted molybdophosphate H6[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 1.2μM/μA dopamine, fast response time (