Fabrication an electrochemical sensor based on composite of Cu-TCPP nanosheets and PSS functionalized graphene for simultaneous and sensitive determination of dihydroxybenzene isomers

A novel electrochemical sensor based on the combination of two-dimensional metal-organic framework Cu-porphyrin (Cu-TCPP) and poly(styrene sulfonate) functionalized graphene (PSS-Gr) denoated as PSS-Gr@Cu-TCPP was constructed and applied to simultaneously determine dihydroxybenzene isomers. The nanocomposite was synthesized by a simple ultrasonic mixing method and characterized by transmission electron microscopy (TEM), UV-Vis absorption and electrochemical techniques. The electrochemical behaviors of dihydroxybenzene isomers including hydroquinone (HQ), catechol (CT) and resorcinol (RS) on PSS-Gr@ Cu-TCPP modified electrode were investigated and their oxidation peak potentials were separated evidently with the oxidation peak currents enhanced significantly on the modified electrode, which were attributed to the remarkable electrocatalytic activity of the nanocomposite on the oxidation of three isomers. Under the optimized conditions, the proposed sensor showed a wide linear concentration range of 1-200 mu M, 0.08-120 mu M and 5-100 mu M with the low detection limit of 1 mu M, 0.08 mu M, 5 mu M for hydroquinone, catechol and resorcinol. In addition, the fabricated electrochemical sensor was successfully applied to detect three dihydroxybenzene isomers in real samples with satisfactory recovery. This work provided a simple and sensitive approach for simultaneous determination of dihydroxybenzene isomers.