Determination of hydroquinone in water by differential pulse voltammetry with polyhematoxylin/TiO2-graphene composite film modified glassy carbon electrode

TiO2-graphene(TiO2-Gr) was coated on glassy carbon electrode(GCE) and hematoxylin was then electropolymerized on the modified electrode to fabricate an electrochemical sensor(polyhematoxylin/TiO2-graphene composite film modified glassy carbon electrode).The electrochemical behaviors of hydroquinone(HQ) on the modified electrode were investigated by cyclic voltammetry.The experimental results showed that the modified electrode had good electrocatalysis performance toward the redox of HQ.The oxidation peak current obviously improved compared to that on the bare GCE and TiO2-Gr/GCE.Differential pulse voltammetry was used for the determination of HQ.The concentration of HQ in the range of 3.0×10-6-1.0×10-3 mol/L showed good linear relationships with the oxidation peak current,with correlation coefficient(R) of 0.993.The detection limit was 1.0×10-7 mol/L(S/N=3).The developed method was used to determination of enviromental water samples with recoveries of 96.2%-105.6%.