Possibilities and limitations in miniaturized sensor design for uric acid

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Biomedical Science

Background:

• Uric acid (UA) is a crucial metabolite in biological fluids.
• Electrochemical determination of UA faces interference from ascorbic acid (AA) due to similar oxidation potentials.
• UA's electrochemical properties make it suitable for fast scan voltammetry (FSV).

Purpose of the Study:

• To investigate the use of FSV at bare carbon fiber electrodes for UA determination.
• To assess the selectivity and sensitivity of FSV in the presence of AA.
• To optimize FSV for stable background currents and improved signal-to-noise ratios.

Main Methods:

• Fast scan voltammetry (FSV) was performed at bare carbon fiber electrodes.
• High scan rates (above 500 V s-1) were employed to resolve UA and AA signals.
• Techniques for achieving stable background currents in FSV were developed.

Main Results:

• FSV demonstrated good selectivity and sensitivity for low UA concentrations amidst high AA levels.
• Kinetic differences between UA and AA allowed for signal resolution without permselective films.
• Stable background currents were achieved, enhancing FSV performance.
• Improved signal-to-noise ratios were observed due to signal averaging and increased peak currents with scan rate.

Conclusions:

• FSV at bare carbon fiber electrodes is a viable method for selective and sensitive UA quantification.
• High scan rates effectively overcome electrochemical interference from AA.
• The developed FSV approach offers advantages for biological sample analysis.