Highly selective and sensitive uric acid sensor based on a self-assembled CdS/CdIn₂S₄ heterojunction.

Area of Science:

• Materials Science
• Electrochemistry
• Biosensing

Background:

• Uric acid detection is vital for diagnosing hypo-/hyper-uricemia.
• Electrochemical sensors offer advantages but face challenges in selectivity, cost, and sampling.
• Existing sensors often rely on invasive blood sampling.

Purpose of the Study:

• To develop an accessible, cost-effective electrochemical sensor for uric acid determination.
• To enhance electrocatalytic activity and sensor performance through heterojunction design.
• To enable non-invasive monitoring of uric acid levels in various biological and food samples.

Main Methods:

• Fabrication of a hetero-structured CdS/CdIn2S4-modified screen-printed carbon electrode (SPCE) via hydrothermal self-assembly.
• Electrochemical characterization and performance evaluation of the sensor for uric acid detection.
• Density functional theory (DFT) calculations to elucidate the mechanism of enhanced electrocatalysis.

Main Results:

• The CdS/CdIn2S4/SPCE achieved high sensitivity (717.5 μA mM⁻¹ cm⁻²), selectivity, a wide linear range (0.5-1000 μM), and a low LOD (0.12 μM).
• The heterojunction interface facilitated electron transfer and hydroxyl radical generation, enhancing uric acid oxidation.
• Successful application in food hygiene inspection and gout monitoring using fish food, serum, urine, and sweat samples with satisfactory accuracy.

Conclusions:

• The developed CdS/CdIn2S4/SPCE provides a promising platform for ultrasensitive, nonenzymatic electrochemical uric acid sensing.
• This approach offers a cost-effective and facile method for developing wearable biosensors for personalized health assessment and food monitoring.
• The study highlights the potential for heterojunction engineering in advancing electrochemical biosensor technology.