Simultaneous Determination of Catechol and Hydroquinone using Gold Nanoparticles/Poly(p-aminobenzenesulfonic acid)/Multi-Walled Carbon Nanotubes Modified Glassy Carbon Electrode

Gold nanoparticles/poly(p-aminobenzenesulfonic acid)/multi-walled carbon nanotubes modified glassy carbon electrode (NanoAu/Poly(ABSA)/MWCNTs/GCE) was prepared for electrochemically determining catechol (CAT) and hydroquinone (HQ) by cyclic voltammetry ( CV ) and differential pulse voltammetry ( DPV ). Results showed that CAT and HQ were electrochemically seperated well, and the difference between oxidation peak potentials of CAT and HQ was 111 mV. The redox currents of CAT and HQ were significantly enhanced on NanoAu/PABSA/MWCNTs/GCE, as compared with on bare GCE. The oxidation peak current ( I pa ) of 10 μ M CAT was 0.24 μ A, and there was almost no detected oxidation current response for 10 μ M HQ on bare GCE. The I pa values on NanoAu/Poly(ABSA)/MWCNTs/GCE increased to 11.3 times for CAT as compared with on GCE, 1.5 times for CAT and 2.5 times for HQ as compared with on MWCNTs/GCE. The linear range of CAT and HQ measurments on NanoAu/Poly(ABSA)/MWCNTs/GCE was 2 ∼ 200 μ M, and the limit of detection (LOD, S/N = 3) was 1.5 μ M for CAT and 1.0 μ M for HQ. This sensor showed high detection sensitivity for CAT (16.53 μ A· μ M –1 ·cm –2 ) and HQ (17.68 μ A· μ M –1 ·cm –2 ). The sensor had been applied for CAT and HQ measurement in lake water with satisfactory results.