Nanomaterials integrated with microfluidic paper-based analytical devices for enzyme-free glucose quantification

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Biomedical Engineering

Background:

• Enzyme-based glucose sensing is crucial for diabetes management but faces challenges with cost and stability.
• Microfluidic paper-based analytical devices (μPADs) offer a promising platform for low-cost diagnostics.
• Developing enzyme-free glucose quantification methods is essential for accessible healthcare.

Purpose of the Study:

• To develop an enzyme-free glucose sensing system integrated into μPADs.
• To utilize gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) for sensitive and selective glucose detection.
• To enable colorimetric glucose readout compatible with smartphone monitoring.

Main Methods:

• Integration of AuNPs as a nanozyme and AgNPs as a colorimetric probe into μPADs.
• Enzyme-free oxidation of glucose by AuNPs, generating hydrogen peroxide (H2O2).
• Colorimetric detection of H2O2 via etching of AgNPs, monitored by smartphone.

Main Results:

• Achieved a linear range of 0.50–10.0 mmol L−1 with R2 = 0.9921.
• Obtained a detection limit (LOD) of 340.0 μmol L−1, within the clinically relevant range.
• Demonstrated high selectivity, recovery (98.47–102.34%), and low RSD (3.58%) in human samples within 20 minutes.

Conclusions:

• The developed enzyme-free nanozyme-based μPAD provides a cost-effective and stable alternative to traditional glucose sensors.
• This technology holds significant potential for point-of-care (POC) diabetes diagnosis, especially in resource-limited settings.
• Smartphone-based readout enhances accessibility and usability for widespread diagnostic applications.