Determination of amiloride at Nafion-CNT-nano-composite film sensor employing adsorptive stripping differential pulse voltammetry

An electrochemical method employing a Nation-carbon nanotube-nano-composite film modified glassy carbon electrode (NAF-CNT-GCE) has been developed for the determination of amiloride (AMI). Cyclic voltammetry, electrochemical impedance spectroscopy and adsorptive stripping differential pulse voltammetry were utilized to study the electrochemical behavior of AMI. Scanning electron microscopy has been performed to study the surface morphology of the electrodes. Studies reveal that the irreversible oxidation of AMI was highly facile on NAF-CNT-GCE for which a plausible mechanism is proposed. The optimized linear working range and detection limit (S/N = 3) are 9.07 x 10(-9)-5.06 x 10(-5) M and 7.02 x 10(-9) M, respectively. The analytical application of the modified GCE is demonstrated by determining AMI in pharmaceutical formulations and biological fluids (urine and plasma). Further, the ease of preparation with high sensitivity, low detection limit and excellent reproducibility makes the proposed method highly advantageous for AMI determination. (C) 2012 Elsevier B.V. All rights reserved.