A Distance-Based Microfluidic Paper-Based Biosensor for Glucose Measurements in Tear Range.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Materials Science

Background:

• Rising diabetes prevalence necessitates accessible diagnostic tools.
• Traditional glucose monitoring can be expensive and require trained personnel.
• Paper-based analytical devices offer a cost-effective and user-friendly alternative.

Purpose of the Study:

• To develop a minimally invasive, user-friendly, and cost-effective glucose biosensor.
• To detect glucose concentration in tear fluid using a microfluidic paper-based analytical device (μPAD).
• To enable naked-eye detection of glucose levels for improved accessibility.

Main Methods:

• Fabrication of a μPAD using CO2 laser technology.
• Immobilization of glucose oxidase/horseradish peroxidase (GOx/HRP) enzymes and tetramethylbenzidine (TMB) reagent.
• Analysis of color intensity and distance-based results using ImageJ and Tracker software.

Main Results:

• The biosensor requires a small sample volume (10 μl) with results observable within 5 minutes.
• Distance-based detection showed linear behavior from 0.1-1.2 mM with R² = 0.9962.
• A limit of detection (LOD) of 0.1 mM was achieved, visible to the naked eye.

Conclusions:

• The developed μPAD provides a rapid and accurate method for glucose detection in tears.
• The device eliminates the need for specialized equipment or trained personnel.
• This technology holds significant potential for diabetes management, particularly in resource-limited settings.