Simultaneous determination of uric acid and ascorbic acid at a ferrocenium-thioglycollate modified electrode

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Self-assembled monolayers (SAMs) are crucial for modifying electrode surfaces.
• Ferrocenium ion adsorption on thioglycollate SAMs creates a novel interface.
• Distinguishing ascorbic acid (AA) and uric acid (UA) electrochemically is challenging.

Purpose of the Study:

• To develop a modified gold electrode for simultaneous and selective detection of AA and UA.
• To evaluate the electrochemical performance of the ferrocenium-thioglycollate modified electrode.
• To demonstrate the electrode's applicability in real biological samples.

Main Methods:

• Fabrication of a gold electrode modified with thioglycollate SAMs and ferrocenium ions.
• Electrochemical characterization using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).
• Differential pulse voltammetry (DPV) for quantitative analysis and detection limit determination.

Main Results:

• The modified electrode successfully separated the oxidation peaks of AA and UA in phosphate buffer solution (pH 7.0).
• Simultaneous determination of AA and UA was achieved using DPV.
• Low detection limits for AA (2.0 x 10(-7) M) and UA (1.0 x 10(-7) M) were obtained.
• The electrode demonstrated applicability for analyzing AA and UA in human urine without pretreatment.

Conclusions:

• The ferrocenium-thioglycollate modified gold electrode offers a robust platform for simultaneous AA and UA detection.
• This method provides a sensitive and selective approach for analyzing these important biomolecules.
• The electrode's performance in human urine highlights its potential for practical diagnostic applications.