Abstract
The authors report the synthesis, characterization and electrochemical study of a nanostructured magnetic molecularly imprinted polymer (Fe3O4-MIP) for the determination of 17-beta-Estradiol (17-beta-E2). The synthesized magnetic nanoparticles (Fe3O4-NPs) and Fe3O4-MIP were investigated using High Resolution Transmission Electron Microscopy (HRTEM), High Resolution Scanning Electron Microscopy (HRSEM), X-Ray Diffraction (XRD) and Fourrier Transform Infrared spectroscopy (FT-IR) as characterization techniques. The electrochemical characterization was studied by cyclic voltammetry and electrochemical impedance spectroscopy Several important parameters controlling the performance of the Fe3O4-MIP based sensor such as the choice of electrochemical analysis technique, the frequency, the effect of pH and the incubation time were investigated. Under the optimal conditions, the oxidation peak current was linearly related to 17-beta-E2 concentration in the range of 0.05-10 mu M. The Fe3O4-MIP based sensor amplifies the oxidation current in square-wave voltammetric measurements which allows reaching 20 nM as detection limit. Furthermore, the Fe3O4-MIP sensing system exhibits a high selectivity towards 17-beta-E2 and was applied successfully for its determination in river water samples. (C) 2016 Elsevier B.V. All rights reserved.