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

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 µM with a limit of detection of 0.02 µM. In addition, the modified CPE was used to determine cabergoline from 0.07 to 350.0 µM with a limit of detection of 0.019 µM. This sensor was employed to simultaneously determine cabergoline and levodopa in urine, serum, and pharmaceuticals.

Keywords:

• Cabergoline
• carbon paste electrode
• cyclic voltammetry
• differential pulse voltammetry
• levodopa
• multiwalled carbon nanotube/ionic liquid/2-(4-oxo-3-phenyl-3,4-dihydroquinazolinyl)-N′-phenyl-hydrazine carbothioamide (FSCNT/IL/2PHC)

Conflict of interest

The authors declare that they have no conflicts of interest.

Ethical approval

This article does not contain studies involving human participants or animals.

Additional information

Funding

This work was supported by the Kerman University of Medical Sciences by Grant number 940660.