A flexible and wearable biosensor for tear glucose measurement

Area of Science:

• Biomedical Engineering
• Biosensors
• Wearable Technology

Background:

• Diabetes management requires frequent glucose monitoring.
• Current methods are invasive and can be uncomfortable.
• Development of non-invasive glucose monitoring is highly desirable.

Purpose of the Study:

• To fabricate and evaluate a flexible, wearable amperometric glucose sensor.
• To assess the sensor's utility for tear glucose monitoring.
• To explore the potential for non-invasive continuous glucose monitoring.

Main Methods:

• Fabrication of a flexible oxygen electrode using Soft-MEMS techniques.
• Immobilization of glucose oxidase (GOD) onto a functional polymer membrane.
• Testing sensor performance with varying glucose concentrations, pH, and temperature.
• Application of the sensor for in-vivo tear glucose measurement in rabbits.

Main Results:

• A linear relationship between glucose concentration and output current (R²=0.998) was observed from 0.025–1.475 mmol/l.
• Sensor performance was dependent on pH (optimal at 7.0) and temperature, indicating enzyme activity influence.
• Tear glucose levels in rabbits ranged from 0.16 to 0.46 mmol/l after glucose administration.
• Tear glucose changes showed a delayed correlation with blood sugar levels.

Conclusions:

• The developed flexible biosensor is suitable for tear glucose monitoring.
• Non-invasive continuous glucose monitoring may be achievable using this technology.
• Further research is warranted to refine the sensor for clinical applications.