Simultaneous electrochemical detection of hydroquinone and catechol using poly(3,4-ethylenedioxythiophene)/reduced graphene oxide/manganese dioxide

Abstract

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 μM for HQ and 0.25–150 μM for CT. The sensor exhibited excellent sensitivity with the detection limits of 0.05 and 0.07 μM 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.