Synthesis of Fe-Cu/TiO2 nanostructure and its use in construction of a sensitive and selective sensor for metformin determination

A carbon paste electrode modified with Fe-Cu/TiO2 was prepared and used for low level determination of metformin (MET) using square wave adsorptive stripping voltammetry (SWAdSV). The Fe-Cu/TiO2 nanoparticle was synthesized by a modified sol-gel method. The surface structure and composition of nanoparticles were characterized by scanning electron microscopy (SEM), X-ray powder diffraction analysis (XRD) and N-2 physisorption. Also, electrochemical properties of the prepared nanocomposite modified electrode were investigated by cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques. Under optimized conditions, the modified electrode exhibited a linear response over the concentration range of 15 nM to 75 mu M MET, with a detection limit of 3 nM. The proposed sensor exhibited a high sensitivity, good selectivity and was successfully applied for MET determination in real samples such as human urine and pharmaceutical formulations. (C) 2014 Elsevier B.V. All rights reserved.