An electrochemical sensor based on the three-dimensional functionalized graphene for simultaneous determination of hydroquinone and catechol

In this study, a simple and sensitive electrochemical analytical method is developed for simultaneous detection of hydroquinone (HQ) and catechol (CC) employing the three-dimensional functionalized graphene (3DFG) modified glass carbon electrode (GCE). The 3DFG modified electrode can distinguish between HQ and CC, with higher oxidation currents in comparison with bare GCE and two-dimensional graphene (Gr) modified electrode, showing the enhanced catalytic activity. The differential pulse voltammetry (DPV) shows that the isomers can be detected sensitively and selectively at 3DFG/GCE with peak-to-peak separation about 100 mV. Under the optimized conditions, the oxidation peak current increases linearly with concentration of HQ ranged from 3.10 x 10(-7) to 1.31 x 10(-5) M and concentration of CC ranged from 2.50 x 10(-7) to 1.29 x 10(-5) M, respectively. The detection limits are 1.0 x 10(-7) M and 8.0 x 10(-8) M for HQ and CC (S/N = 3), respectively. Moreover, the proposed method has been successfully applied to the simultaneous determination of HQ and CC in real water samples with satisfactory recoveries. (C) 2014 Elsevier B.V. All rights reserved.