Adsorptive stripping differential pulse voltammetric determination of metoprolol at Nafion-CNT-nano-composite film sensor

An electrochemical method employing a Nafion-carbon nanotube-nano-composite film modified glassy carbon electrode (NAF-CNT-GCE) has been developed for the determination of metoprolol (MET). Cyclic voltammetry and adsorptive stripping differential pulse voltammetry were employed to study the electrochemical behavior of MET. Surface morphology of the electrodes was done using scanning electron microscopy. Studies reveal that the irreversible oxidation of MET was extremely facile on NAF-CNT-GCE. The optimized linear working range and detection limit (S/N = 3) are 7.02 x 10(-8) to 9.0 x 10(-6) M and 3.51 x 10(-8) M respectively. The analytical application of the modified GCE is demonstrated by determining MET in pharmaceutical formulations and biological fluids (serum and urine). The present sensor portrays certain advantages such as high sensitivity, simplicity, low detection limit and excellent reproducibility making the proposed method highly advantageous for MET determination. (C) 2012 Elsevier B.V. All rights reserved.