Electrochemical Determination of Hydroquinone and Catechol Using Multi-walled Carbon Nanotubes/eosin Y Modified Glassy Carbon Electrode

A new glassy carbon electrode modified with eosin Y (EY) and multiwalled carbon nanotubes (MWCNTs) film was fabricated. The modified electrode was used for highly selective and sensitive determination of hydroquinone (HQ) and catechol (CC). The electrode combined the advantages of using EY and MWCNTs, and exhibited a dramatic electrocatalytic effect on the oxidation of HQ and CC. The modified GCE showed two well-defined redox peaks for HQ and CC in cyclic voltammetry (CV) with a peak potential separation of 110 mV, which ensured the anti-interference ability of the electrochemical sensor and made simultaneous determination of dihydroxybenzene isomers possible in real samples. The oxidation peak currents were linear to HQ/CC in the range from 4.0x10(-7) to 5.0x10(-5) M with the detection limits of 1.0 x 10(-8) M (S/N=3) for HQ and 1.5 x 10(-8) M (S/N=3) for CC, respectively. In addition, the proposed sensor was successfully applied to the simultaneous determine HQ and CC in real water samples with reliable recovery.