Simultaneous Determination of Epinephrine, Dopamine, Ascorbic Acid and Uric Acid by Polydopamine-nanogold Composites Modified Electrode

摘要

A facile polydopamine (PDA)-nanogold composites modified glassy carbon electrode (GCE) wasprepared by a one-pot method and used for the sensitive determination of epinephrine (EP), dopamine(DA), ascorbic acid (AA) and uric acid (UA) simultaneously in this work. Under a mild spontaneousreaction condition, DA as a reducing agent and monomer, and HAuCl4 as an oxidant to trigger DApolymerization and the source of gold nanoparticles, were mixed to yield composites of DA polymerand gold nanoparticles, which were then anchored on GCE by electropolymerization of the remainingDA monomer. The resultant electrode exhibited excellent electrocatalytic redox activities toward EP,DA, AA and UA. Furthermore, although the oxidation peaks of EP and DA at the modified electrodeappeared at a same potential of 230 mV, three well-defined oxidation peaks for AA, EP, DA and UA(50, 230, 380 mV) and two non-interference reduction peaks for EP (-150 mV) and DA (190 mV) werepresented. By virtue of this interesting phenomenon, for the first time the simultaneous detection ofEP, DA, AA and UA using the proposed sensor has been achieved by cyclic voltammetry (CV) andsquare wave voltammetry (SWV). The calibration curves for EP, DA, AA and UA were acquired inthe range of 1.00.0 M, 1.00.0 M, 40.0000.0 M, and 0.800.0 M with the detection limits(S/N = 3) of 0.1 M, 0.08 M, 5.0 M and 0.06 M, respectively. The proposed method is simple,sensitive and convenient, and was successfully applied to the determination of EP, DA, AA and UA inhuman blood serum and urine samples.