MOFs-on-MOFs modified wearable electrochemical microneedle array for uric acid detection

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Conventional uric acid (UA) detection methods require invasive blood or urine tests, hindering convenience and real-time monitoring.
• There is a need for non-invasive, wearable biosensors for continuous UA level assessment.

Purpose of the Study:

• To develop a novel microneedle array-based wearable electrochemical sensor for detecting UA in skin interstitial fluid (ISF).
• To integrate advanced bi-metal-organic framework (bi-MOF) materials with a microneedle system for enhanced sensing capabilities.

Main Methods:

• Fabrication of a screen-printed electrode (SPE) modified with a bi-MOF nanocomposite using a "MOFs on MOFs" strategy (HKUST-1 and Eu-MOF).
• Development of a 3D-printed hollow microneedle array patch (HMNsAP) with a microvalve for efficient and safe ISF extraction.
• Electrochemical detection of UA in ex-vivo rat skin samples.

Main Results:

• The bi-MOF modified SPE demonstrated enhanced surface area, porosity, and electron transfer efficiency.
• The HMNsAP system facilitated effective ISF extraction with a microvalve preventing backflow, ensuring biosafety.
• The sensor achieved a low limit of detection (20 nM), high recovery rates (98.6%-100.4%), excellent selectivity, and reproducibility (RSD = 1.68%).

Conclusions:

• The developed wearable electrochemical sensor effectively monitors UA in ISF, overcoming limitations of conventional methods.
• The combination of advanced bi-MOF materials and innovative microneedle technology offers significant advantages for precise UA monitoring.
• This technology holds promise for personalized diagnostics and continuous health monitoring applications.