Synthesis of Polyfluorinated Azobenzene Intercalated Tantalum Tungstate Nanocomposite for Determination of Dopamine and Ascorbic Acid

Abstract

A sandwich-structured C3F7-azo+-TaWO6 nanocomposite used as an electrochemical sensor for simultaneous determination of dopamine (DA) and ascorbic acid (AA) was synthesized by guest-guest exchange method. n-PrNH3 +-TaWO6 precursor was ion-exchanged with cationic polyfluorinated azo dye, trans-[2-(2,2,3,3,4,4,4-heptafluorobutylamino)ethyl]-{2-[4-(4-hexyphenylazo)-phenoxy]ethyl} dimethylammonium bromide (abbreviated as C3F7-azo+Br−). The structure and morphology were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive spectrometer analysis (EDS) and Fourier transform infrared spectrometer (FTIR). Differential pulse voltammetry (DPV) and cyclic voltammetry (CV) were used to test the electrochemical properties of C3F7-azo+-TaWO6 nanocomposite. The experimental results show that C3F7-azo+-TaWO6/GCE can detect AA and DA at the same time, with the potential difference reaching 356 mV. Moreover, electrochemical sensing toward DA and AA on C3F7-azo+-TaWO6/ GCE exhibits low detection limits of 0.81 μM and 1.6 μM, respectively, each in a linear range of 0.05 to 0.31 mM.