▎ 摘　　要

A highly sensitive electrochemical method was performed for simultaneous detection of hydroquinone (HQ) and catechol (CT) using poly(3,4-ethylenedioxythiophene)/reduced graphene oxide/manganese dioxide (PEDOT/rGO)/MnO2) composite. The PEDOT/rGO/MnO2 composite was prepared in two steps via cyclic voltammetry (CV). The composite was characterized using field emission scanning electron microscope (FESEM), Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), CV and electrochemical impedance spectroscopy (EIS). The PEDOT/rGO/MnO2 composite showed excellent electrochemical catalytic activity towards the oxidation of HQ and CT by displaying well-separated oxidation peaks and high oxidation peak currents of HQ and CT. The composite showed linear responses from 0.5 to 150 mu M for HQ and 0.25-150 mu M for CT. The sensor exhibited excellent sensitivity with the detection limits of 0.05 and 0.07 mu M for HQ and CT, respectively. In addition, PEDOT/rGO/MnO2 composite showed excellent reproducibility, repeatability and stability. The PEDOT/rGO sensor was successfully studied in the real sample of lake water and tap water with high recoveries.