Abstract

A ternary nanocomposite of Fe3O4-SnO2-Gr was synthesized and characterized by scanning electron microscopy and X-ray diffraction. A novel sensing layer was constructed by incorporation of the prepared nanocomposite into carbon paste electrode (CPE) for the simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA). Three clear and well-separated voltammetric peaks along with the remarkably increased electro-oxidation currents were obtained on the modified electrode (Fe3O4-SnO2-Gr/CPE) in differential pulse voltammetry (DPV) measurements. The linear calibration curves were obtained by plotting the peak currents against the analytes concentrations in the range of 0.1 to 23.00, 0.02 to 2.8, and 0.015 to 2.40 mu M, with detection limits of 62.0, 7.1 and 5.0 nM for AA, DA, and UA, respectively. Additionally, the Fe3O4-SnO2-Gr/CPE presented a noticeable anti-interference ability, stability, and reproducibility. Also, the obtained electrode showed satisfactory results when applied for the determination of the AA, DA and UA in biological fluids and pharmaceutical samples. (C) 2016 Elsevier B.V. All rights reserved.