Zeolite A functionalized with copper nanoparticles and graphene oxide for simultaneous electrochemical determination of dopamine and ascorbic acid

A novel Cu-zeolite A/graphene-modified glassy carbon electrode was applied in the simultaneous electrochemical determination of dopamine (DA) and ascorbic acid (AA). The potential difference between the two oxidation peaks of DA and AA were over 200mV. The electrocatalytic oxidation currents of DA were linearly related to the corresponding concentration in the range of 1.0×10−7–1.9×10−5M. [Display omitted] ► Cu nanoparticles doped-zeolite A/graphene (CuZEA/RGO) modified electrode was prepared. ► The composites of CuZEA/RGO were prepared via reduction of Cu2+ functionalized zeolite A and graphene oxide in one pot. ► The modified electrode was presented for the simultaneous determination of DA and AA. ► The proposed electrode showed a higher electrocatalytic performance. A novel Cu-zeolite A/graphene modified glassy carbon electrode for the simultaneous electrochemical determination of dopamine (DA) and ascorbic acid (AA) has been described. The Cu-zeolite A/graphene composites were prepared using Cu2+ functionalized zeolite A and graphene oxide as the precursor, and subsequently reduced by chemical agents. The composites were characterized by X-ray diffraction, Fourier transform infrared spectra and scanning electron microscopy. Based on the Cu-zeolite A/graphene-modified electrode, the potential difference between the oxidation peaks of DA and AA was over 200mV, which was adequate for the simultaneous electrochemical determination of DA and AA. Also the proposed Cu-zeolite/graphene-modified electrode showed higher electrocatalytic performance than zeolite/graphene electrode or graphene-modified electrode. The electrocatalytic oxidation currents of DA and AA were linearly related to the corresponding concentration in the range of 1.0×10−7–1.9×10−5M for DA and 2.0×10−5–2.0×10−4M for AA. Detection limits ( S/N =3) were estimated to be 4.1×10−8M for DA and 1.1×10−5M for AA, respectively.