A dopamine electrochemical sensor based on Pd-Pt alloy nanoparticles decorated polyoxometalate and multiwalled carbon nanotubes

A novel sensor was assembled for electrochemical sensing of dopamine (DA) based Pd-Pt alloy nanoparticles (Pd@Pt) decorated polyoxometalate (PMo9V3) on the surface of indium-tin oxide (ITO) electrodes which was pre-modified by multiwalled carbon nanotubes (CNTs). The surface morphology of the sensor was recorded by scanning electron microscope (SEM), and the elements on the modified electrode were characterized from a representation of X-ray photoelectron spectroscopy (XPS). The combination of Pd@Pt and CNTs with PMo9V3 significantly enhanced the peak response current and decreased the overpotential of dopamine oxidation. Meanwhile the oxidation reaction of dopamine can be separated from ascorbic acid and uric acid, improving the selectivity of the sensor. The as-fabricated sensor exhibited a wide linear response of 2.50 x 10(-8) to 1.78 x 10(-4) M, low detection limit of 1.25 x 10(-8) M (S/N = 3) and short response time (< 1.0 s). Furthermore, the sensor was employed for determination of DA in human serum and dopamine hydrochloride injection, which manifested the potential application of the modified electrode.