Simultaneous determination of dihydroxybenzene isomers based on graphene-graphene oxide nanocomposite modified glassy carbon electrode

In this paper, a novel graphene-graphene oxide (GR-GO) nanocomposite which could be dispersed well in water was fabricated by mixing GR and GO together with the help of ultrasonication. The significant advantage of the method developed here is the omission of any stabilizing compound or organic solvent. The prepared material was characterized by the scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and electrochemical impedance spectra. The application of GR-GO nanocomposite in simultaneous determination of hydroquinone (HQ) and catechol (CC) was investigated by cyclic voltammetry and differential pulse voltammetry. The oxidation peak potential difference between HQ and catechol CC was about 102 mV, which was wide enough to clearly discriminate the dihydroxybenzene isomers. In the presence of 50 μM isomer, the oxidation peak currents of HQ and CC were linear over the range of 0.5–300 μM with the detection limits of 0.16 μM (S/N = 3) for HQ and 0.2 μM (S/N = 3) for CC, respectively.