Electrochemical Determination of Levodopa and Cabergoline by a Magnetic Core-Shell Iron (II,III) Oxide@Silica/Multiwalled Carbon Nanotube/Ionic Liquid/2-(4-Oxo-3-Phenyl-3,4-Dihydroquinazolinyl)- N′-Phenyl-Hydrazine Carbothioamide (FSCNT/IL/2PHC) Modified Carbon Paste Electrode

Abstract

Abstract This study reports a highly selective and sensitive electrochemical technique for levodopa and cabegoline based on the enhanced electrochemical response to magnetic core-shell Fe3O4@SiO2/multiwalled carbon nanotubes nanocomposite/N-butylpyridinium hexafluorophosphate (as an ionic liquid [IL])/2-(4-oxo-3-phenyl-3,4-dihydroquinazolinyl)-N′-phenyl-hydrazine-carbothioamide (2PHC) modified carbon paste electrode (FSCNT/IL/2PHC/CPE). Therefore differential pulse voltammetry (DPV) and the cyclic voltammetry (CV) were utilized to examine the electrocatalysis of levodopa and cabergoline at the modified electrode. After optimizing the conditions, the sensor had favorable electrochemical responses toward levodopa and cabergoline. DPV indicated a significantly higher electrochemical signal for levodopa and cabergoline at the modified electrode, which provides the sensitivity of the sensor for the analytes. The peak current for levodopa was linear between 0.06 and 400.0\u2009µM with a limit of detection of 0.02\u2009µM. In addition, the modified CPE was used to determine cabergoline from 0.07 to 350.0\u2009µM with a limit of detection of 0.019\u2009µM. This sensor was employed to simultaneously determine cabergoline and levodopa in urine, serum, and pharmaceuticals.