Electrochemical sensor for isoproterenol based on a carbon paste electrode modified with carbon nanotube and modifier

Isoproterenol is a synthetic sympathomimetic amine that is structurally related to epinephrine but acts almost exclusively on beta receptors.It is a medication used for the treatment of pulmonaryhypertension andallergic emergencies, bronchitis, cardiac chock and heartattack. It is also wellknown that isoproterenol generates free radicals leading to lipid peroxidation, which causeirreversible damage to the myocardium [1]. Increasein formation of reactive oxygen species(ROS) during ischemia/reperfusion andthe adverse effects of oxygen radicals on myocardiumhave been well established by both direct and indirectparameters. Thus, the excessof the drug causes loss of functionalintegrity and necrotic lesion in heart muscle [2], Therefore,fromhealth viewpoints, development of a sensitive analytical method for thedetermination of isoproterenol isvery important. Several methods have been described for the determination of isoproterenol such as spectrofluorimetry, spectrophotometry,liquid and gas chromatographic and electrochemical methods [3]. Among them electrochemical methods are practical and attractive because electrochemical instrumentation is usually fast, relatively inexpensive, simple, power efficient, accurate and highly sensitive.Moreover, thedevelopment of a rapid electrochemicalmethod for isoproterenol determination that does not require sample pretreatmentis possible. It is known thatthe electrochemical oxidation of isoproterenol atbare electrode surfaces requires highoverpotential[4, 5]. Carbon paste is one of the most popular materials toprepare solid-state electrodes, with highapplicability in electrochemistryresearch.The easeand speed of preparation and obtaining a new reproducible surface,low residual current, porous surface and low cost are advantages ofcarbonpaste electrodes (CPEs) over all other solid electrodes [6]. In the present work, 2-Chlorobenzoyl ferrocene (2CBF) was synthesized and used to construct a modified-carbon nanotube paste electrode. The electro-oxidation of isoproterenol at the surface of the modified electrode was studied using cyclic voltammetry (CV), chronoamperometry (CHA) and square wave voltammetry (SWV). Under the optimized conditions, the square wave voltammetric peak currents of isoproterenol increased linearly with isoproterenol concentrationsin the ranges of 2.5×10-7 to 8.0×10−5 M and detection limit of 9.0×10-8 M was obtained for isoproterenol. Finally this modified electrode was used for determination of isoproterenol in real samples

Keywords:

Isoproterenol , Carbone nanotube , Electrocatalytic , Carbon paste electrode , Modifier