Cefixime detection by a novel electrochemical sensor based on glassy carbon electrode modified with surface imprinted polymer/multiwall carbon nanotubes

A new selective voltammetric sensor based on molecularly imprinted polymer immobilized on multiwall carbon nanotube surface was reported for determination of cefixime in this paper. For this, cefixime was first assembled on the surface of carboxyl-functionalized multiwall carbon nanotube modified glassy carbon electrode by the formation of covalent bonds. Then molecular imprinting polymers were formed with incubating the prepared electrode in mixture solution of acrylamide as functional monomer and N,N methylenebisacrylamide as cross linker. Ag dendrites were electrodeposited on the surface of molecular imprinting polymers and were used to increase the electrode surface area and to amplify the sensor signal. The morphology of the fabricated electrode was investigated by cyclic voltammetry, scanning electron microscopy, and electrochemical impedance spectroscopy techniques. Under the optimal experimental condition, the voltammetry responses were linearly related to cefixime concentration between 0.01 and 600.0 mu M and a limit of detection of 0.001 mu M was achieved. Finally, the proposed sensor was successfully applied to determination of cefixime in pharmaceutical formulations and urine samples. (C) 2016 Elsevier B.V. All rights reserved.