Amperometric enzyme electrodes for xanthine determination with different mediators.

Area of Science:

• Electrochemistry
• Biosensors
• Analytical Chemistry

Background:

• Xanthine determination is crucial in various biological and food analyses.
• Development of sensitive and selective electrochemical sensors is an ongoing research area.
• Carbon paste enzyme electrodes offer a versatile platform for biosensing applications.

Purpose of the Study:

• To develop and optimize novel amperometric carbon paste enzyme electrodes for xanthine detection.
• To investigate the efficacy of 1,4-benzoquinone and poly(vinylferrocene) as mediators.
• To evaluate the performance of the developed electrodes in real sample analysis.

Main Methods:

• Fabrication of carbon paste enzyme electrodes modified with 1,4-benzoquinone (BQ-CPEE) and poly(vinylferrocene) (PVF-CPEE).
• Optimization of parameters influencing the analytical performance of the modified electrodes.
• Electrochemical characterization and determination of xanthine in various concentration ranges.
• Assessment of hypoxanthine response and application in real sample analysis.

Main Results:

• BQ-CPEE showed linear response ranges from 1.9 × 10-7 M to 5.5 × 10-6 M and 5.2 × 10-5 M to 8.2 × 10-4 M.
• PVF-CPEE exhibited linear ranges at 1.9 × 10-7–2.1 × 10-6 M, 1.9 × 10-6–1.0 × 10-5 M, and 1.1 × 10-4–8.8 × 10-4 M.
• Both modified electrodes achieved a detection limit of 1.0 × 10-7 M for xanthine.
• Good recovery rates were obtained when applying the electrodes to real samples.

Conclusions:

• The developed amperometric carbon paste enzyme electrodes are effective for sensitive xanthine determination.
• Both 1,4-benzoquinone and poly(vinylferrocene) serve as efficient mediators, enabling sensitive electrochemical detection.
• The optimized electrodes demonstrate potential for practical application in analyzing xanthine in real-world samples.