Abstract

A simple methodology was used to develop a novel sensor based on a core-shell/molecularly imprinted polymer (MIP) for the determination of ephedrine. The Fe3O4@SiO2@TiO2-MIP nanocomposite with a well-defined core-shell structure was synthesized using a simple imprinting strategy. The morphology of the synthesized nanocomposite was observed by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and the properties of the sensor were examined by cyclic voltammetry and electrochemical impedance spectroscopy. The fabricated electrochemical sensor based on the Fe3O4@SiO2@TiO2-MIP nanocomposite exhibits great features such as a remarkably low detection limit of 0.0036 mu mol L-1 (3S(b)/m), superb selectivity in discriminating ephedrine from its structural analogues and good anti-interference ability towards several co-existing substances. Also, it was used to detect the concentration of ephedrine in the linear range of 0.0090-2.8 mu mol L-1. Moreover, the proposed method demonstrates excellent repeatability and stability, with a relative standard deviation (RSD) of less than 1.4 and 1.6, respectively. Analysis of ephedrine in pharmaceutical dosage forms and biological fluids is successfully carried out without the assistance of complicated pretreatment. The Fe3O4@SiO2@TiO2-MIP nanocomposite presented here with admirable merits makes it a promising candidate for developing an electrochemical sensor device to perform routine analysis of ephedrine.