Electrochemical oxidation of chlorpheniramine at polytyramine film doped with ruthenium (II) complex: Measurement, kinetic and thermodynamic studies

• Published in: Electrochimica acta Vol. 135; pp. 319 - 326
• Main Authors: Khudaish, Emad A., Al-Hinaai, Mohammed, Al-Harthy, Salim, Laxman, Karthik
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 20.07.2014
• Subjects: Chlorpheniramine maleate; Construction; Electrochemical impedance spectroscopy; Electrodes; Oxidation; Polytyramine; Reaction kinetics; Sensors; Thermodynamics; Tris(bipyridyl)ruthenium (II); X-ray photoelectron spectroscopy; Sensors; Chlorpheniramine maleate; Polytyramine; Tris(bipyridyl)ruthenium (II)
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2014.05.029

•XPS data confirm doping of ruthenium onto the polytyramine moiety.•Doping of Ru decreases the Pty resistivity and increases the electron transfer kinetics.•The resulting sensor is stable for a large range of CPM concentration.•Estimated values of thermodynamic and kinetic parameters were comparable.•Application to commercial dosage forms was excellent and satisfactory. A solid-state sensor based on polytyramine film deposited at glassy carbon electrode doped with tris(2,2′-bipyridyl)Ru(II) complex (Ru/Pty/GCE) was constructed electrochemically. A redox property represented by [Ru(bpy)3]3+/2+ couple immobilized at the Pty moiety was characterized using typical voltammetric techniques. The XPS data and AFM images confirm the grafting of Ru species on the top of Pty while the electrochemical impedance spectroscopy (EIS) data supports the immobilization of both surface modifiers onto the GCE. The constructed sensor exhibits a substantial reactivity, stability and high sensitivity to chlorpheniramine maleate (CPM) oxidation. The detection limit (S/N=3) was brought down to 338nM using differential pulse voltammetry method. Thermodynamic and kinetic parameters were evaluated using hydrodynamic method. The apparent diffusion coefficient and the heterogeneous electron transfer rate constant for the CPM oxidation were 2.67×10−5cm2 s−1 and 3.21×10−3cm s−1, respectively. Interference studies and real sample analysis were conducted with excellent performance and satisfactory results.