Dopamine and uric acid electrochemical sensor based on a glassy carbon electrode modified with cubic Pd and reduced graphene oxide nanocomposite

A cubic Pd and reduced graphene oxide modified glassy carbon electrode (Pd/RGO/GCE) was fabricated to simultaneously detect dopamine (DA) and uric acid (UA) by cyclic voltammetry (CV) and different pulse voltammetry (DPV) methods. Compared with Pd/GCE and RGO/GCE, the Pd/RGO/GCE exhibited excellent electrochemical activity in electrocatalytic behaviors. Performing the Pd/RGO/GCE in CV measurement, the well-defined oxidation peak potentials separation between DA and UA reached to 145 mV. By using the differential pulse voltammetry (DPV) technique, the calibration curves for DA and UA were found linear with the concentration range of 0.45-421 mu M and 6-469.5 mu M and the detection limit (S/N = 3) were calculated to be 0.18 mu M and 1.6 mu M, respectively. Furthermore, the Pd/RGO/GCE displayed high selectivity when it was applied into the determination of DA and UA even though in presence of high concentration of interferents. Additionally, the prepared electrochemical sensor of Pd/RGO/GCE demonstrated a practical feasibility in rat urine and serum samples determination. (C) 2017 Elsevier Inc. All rights reserved.