Highly permselective uric acid detection using kidney cell membrane-functionalized enzymatic biosensors.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Clinical Diagnostics

Background:

• Abnormal blood uric acid (UA) levels are linked to gout, necessitating accurate detection for early diagnosis.
• Existing electrochemical UA biosensors face interference from blood antioxidants, limiting diagnostic accuracy.
• Uric acid transporter 1 (URAT1), abundant in kidney cell membranes (KCM), offers selective UA permeability.

Purpose of the Study:

• To develop a novel UA biosensor utilizing URAT1's selective permeability for improved gout diagnosis.
• To address the limitations of current biosensors susceptible to antioxidant interference.
• To create a stable and reproducible sensor for UA detection in biological samples.

Main Methods:

• Fabrication of a KCM-coated UA biosensor (KCM sensor) leveraging URAT1.
• Verification of KCM coating using electron microscopy and atomic force microscopy.
• Assessment of UA detection range, limit of detection, selectivity against antioxidants, and performance in human serum.

Main Results:

• The KCM sensor demonstrated UA detection in the 0-1000 μM range with an 8.5 μM limit of detection.
• URAT1 inhibition significantly reduced UA permeability, confirming its role in detection.
• The sensor showed high selectivity in the presence of antioxidants and maintained performance in human serum with high reproducibility (0.5-1.6% deviation).

Conclusions:

• The KCM sensor provides a selective and accurate method for UA detection, enabling early gout diagnosis.
• URAT1 is crucial for the sensor's UA detection capability, overcoming antioxidant interference.
• The developed biosensor exhibits excellent stability and reproducibility for clinical applications.