Selective detection of dopamine based on Cu2O@Pt core-shell nanoparticles modified electrode in the presence of ascorbic acid and uric acid

The Cu2O@Pt nanoparticles were prepared by a two-step method, using Vulcan XC-72 carbon as support (donated as Cu2O@Pt/C). Transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy were used to characterize the resulting Cu2O@Pt core-shell nanoparticles. The chemically modified electrode based on Cu2O@Pt/C nanocomposites was employed to eliminate the interference from ascorbic acid and uric acid for the sensitive and selective determination of dopamine. The electrochemical results indicate that the Cu2O@Pt/C nanocomposites show better electrocatalytic activity for the oxidation of dopamine than Pt/C nanocomposites with a linear range from 10 nM to 1027.16 μM, a detection limit of 3 nM (S/N = 3) and sensitivity of 638.0 μA mM−1 cm−2. Moreover, the sensor exhibits excellent long-time stability, good reproducibility and can be applied for practical application.