This study is consisting of two sections. At first section an electrochemical sensor was fabricated for sucrose using glassy carbon electrode (GCE) modified with cupric oxide (CuO)/multiwall carbon nanotubes (MWCNTs) nanocomposite. Scanning electron microscopy (SEM) and X–ray diffraction (XRD) were used to characterize the morphology and structure of the nanocomposite. The electrochemical characterization of CuO/MWCNTs/GCE was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Synergistic effect of CuO/MWCNTs/GCE led to a selective oxidation of sucrose in an alkaline medium. The electrode was applied to measure sucrose in sugar beet juices, demonstrating its potential as a sucrose sensor. In second section, a novel and selective sensor was successfully developed for the determination of sucrose by integrating electropolymerization of molecularly imprinted polymer with multiwall carbon nanotubes. The sensor was prepared by electropolymerizing of o-phenylenediamine in the presence of template sucrose on a MWCNTs/GCE. The template was removed using acetonitrile/acetic acid mixture. The sensor preparation conditions were optimized using response surface methodology. The sensor was studied with respect to its response to hexacyanoferrate(III) as a probe. Capturing of sucrose by the modified electrode causes decreasing response of the electrode to hexacyanoferrate(III). Calibration curve was obtained in the sucrose concentration range of 0.01- 10.0 mmol L -1 with a limit of detection 4 µmol L -1 sucrose. This sensor provides an efficient way for eliminating interferences from compounds with similar structures to that of sucrose. The sensor was successfully applied to determine sucrose in sugar beet juices. Key Words Sucrose; Electrochemical sensor; Molecularly imprinted polymer; Nanocomposite; Sugar beet.
