Paper-based laser-written CoO-graphene biosensor for wireless sweat uric acid detection

Area of Science:

• Materials Science
• Electrochemistry
• Biomedical Engineering

Background:

• Uric acid is a key biomarker for gout, kidney dysfunction, and cardiovascular disease.
• Continuous monitoring of uric acid is crucial for timely intervention and improved patient outcomes.
• Current monitoring methods are invasive, lab-dependent, and unsuitable for continuous or point-of-care use.

Purpose of the Study:

• To develop a sustainable, non-enzymatic sensor for real-time uric acid detection.
• To create a flexible, wireless platform for wearable uric acid monitoring.
• To establish a low-cost, scalable fabrication method for metal oxide-carbon hybrid biosensors.

Main Methods:

• Fabrication of a cobalt oxide-infused graphene sensor on a paper substrate via direct laser writing.
• Utilizing multivalent Co2+/Co3+ redox couples for non-enzymatic uric acid oxidation.
• Integration of the sensor into a flexible near-field communication (NFC) tag for wireless, battery-free operation.

Main Results:

• The sensor demonstrated high sensitivity (9.96 µA·µM⁻¹) and a low detection limit (1.08 µM) for uric acid.
• The sensor exhibited excellent mechanical robustness, with minimal frequency change under bending.
• The developed platform enabled wireless, battery-free monitoring of uric acid in human sweat.

Conclusions:

• A sustainable, one-step method for fabricating metal oxide-carbon hybrid biosensors using laser-written cobalt-treated paper was established.
• The developed wearable sensor offers a promising, non-invasive approach for continuous uric acid monitoring.
• This technology paves the way for next-generation point-of-care diagnostics and personalized health management.