Ionic liquid mediated synthesis of TiO2-ZnO-BMIMBr nanocomposite for electrochemical sensing of neurotransmitter.

An immensely selective sensor TiO₂-ZnO-BMIMBr nanocomposite was developed as sensing materials for dopamine. ILs ([BMIM]⁺[Br]⁻) contribute as green dispersing media for the nanostructures, improving conductivity and biocompatibility. The surface morphologies, microstructure, and chemical compositions of the nanocomposite were probed by scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), RAMAN, X-ray diffraction (XRD) and Thermo gravimetric analysis (TGA-DTA). The electrochemical behaviours of DA at the bare and modified GCEs (TiO₂, ZnO, TiO₂-ZnO-BMIMBr) were investigated in acetate buffer solution (0.1 M, pH 7.4) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Compared with the bare electrode, TiO₂-ZnO-BMIMBr/GCE shows the oxidation peak current (ipa) of increased magnitude, owing to the synergistic effect between TiO₂ and ZnO in TiO₂-ZnO-BMIMBr. The detection limit of the nanocomposite was found 4.09 μM by CV and 8.14 μM by DPV (S/N = 3). Moreover, the response peak current of DA is not interfered with the coexistence of ascorbic acid (AA), uric acid (UA), and glucose. TiO₂-ZnO-BMIMBr has tremendous prospects for the detection of DA in urine samples. [ABSTRACT FROM AUTHOR]