Determination of isoproterenol in pharmaceutical and biological samples using a pyrogallol red multiwalled carbon nanotube paste electrode as a sensor

Isoproterenol (ISPR) is an important catecholamine-based drug that is widely used in the treatment of heart disease. However, overdose of this drug is very dangerous to the human body. In this study, a new sensor based on a pyrogallol red modified-multiwalled carbon nanotube paste electrode (PGRMMWCNTPE) was prepared and used for high sensitivity determination of ISPR in aqueous solution. Electrocatalytic oxidation of ISPR at the PGRMMWCNTPE was investigated by chronoamperometry, cyclic voltammetry, and square-wave voltammetry. The values of the catalytic rate constant, electron transfer coefficient, and diffusion coefficient for ISPR oxidation were then calculated using voltammetric data. A linear calibration curve was constructed for ISPR concentration in the range 0.8-570 mu mol/L with a detection limit of 0.47 mu mol/L ISPR. The sensor was then applied to the determination of ISPR in urine and drug samples with satisfactory results. (C) 2016, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.