Voltammetric determination of nifedipine using a β-cyclodextrin modified multi-walled carbon nanotube paste electrode

An electrochemical method employing a beta-cyclodextrin modified carbon nanotube paste electrode (beta CD-CNT-PE) has been developed for the determination of nifedipine (NIF). Cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse adsorptive stripping voltammetry were utilized to study the electrochemical behaviour of NIF. The surface morphology of the electrodes has been studied by scanning electron microscopy. Studies reveal that the irreversible oxidation of NIF was highly facile on beta CD-CNT-PE for which a plausible mechanism is proposed. The optimized linear working range and detection limit (S/N = 3) are 4.77 x 10(-8) to 2.00 x 10(-5) and 1.48 x 10(-8) M, respectively. The analytical application of the modified electrode is demonstrated by determining NIF in pharmaceutical formulations and biological fluids (urine and serum). Further, the ease of preparation with high sensitivity, low detection limit and excellent reproducibility makes the proposed method highly advantageous for NIF determination. (C) 2013 Elsevier B. V. All rights reserved.