▎ 摘　　要

In this article, we demonstrate the potentiostatic electrodeposition of poly(3,4-ethylenedioxythiophene) (PEDOT) on reduced graphene oxide (RGO) to develop a nanocomposite-modified electrode that separates three coexisting biofluids - ascorbic acid (AA), dopamine (DA), and uric acid (UA) - in a 0.1M Phosphate buffer solution at a physiological pH (7.4). The texture, physicochemical properties, and electrochemical behavior of the PEDOT-RGO were explored using UV-visible spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, electron microscopic techniques, and electrochemical impedance spectroscopy (EIS). A PEDOT-RGO/GCE was evaluated with respect to a bare GCE, RGO/GCE, and PEDOT/GCE for the simultaneous sensing of AA, DA, and UA. The difference in voltammetric peak potentials was about 180 mV between AA and DA and 120 mV between DA and UA. The differential pulse voltammetric sensor provided a linear calibration for a wide concentration range (0.1-907 mu M for AA, 0.1-901 mu M for DA, and 0.1-701 mu M for UA) with detection limits of 1.5 mu M, 0.6 mu M, and 0.2 mu M for AA, DA, and UA, respectively. The developed sensor was validated by the detection of AA, DA, and UA in a vitamin C tablet, a dopamine hydrochloride injection, and human serum samples. (C) 2019 Elsevier B.V. All rights reserved.