Selective sensing of catechol and hydroquinone based on poly(3,4-ethylenedioxythiophene)/nitrogen-doped graphene composites

A highly sensitive and selective method was developed for the simultaneous detection of catechol and hydroquinone on a poly(3,4-ethylenedioxythiophene)/nitrogen-doped graphene composite layer. The composite modified electrode was prepared by the electro-polymerization of 3,4-ethylenedioxythiophene on the nitrogen-doped graphene coated glassy carbon electrode. The composite film, characterized by Raman spectra and SEM, was highly efficient to catalyze the redox of catechol and hydroquinone. Two couple of well-defined redox peaks of catechol and hydroquinone could be observed with good reversibility and the enhanced current responses were obtained. Differential pulse voltammetry was used in the simultaneous and quantitative determination of catechol and hydroquinone under the optimized experiment parameters. The proposed sensor based on poly(3,4-ethylenedioxythiophene)/nitrogen-doped graphene exhibited a linear response to the concentrations ranging from 1 to 10 μM with a low detection limit of 0.26 μM for catechol and 0.18 μM for hydroquinone, respectively.