Recording of subcutaneous glucose dynamics by a viscometric affinity sensor

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Endocrinology

Background:

• Continuous glucose monitoring (CGM) is crucial for diabetes management.
• Existing CGM technologies often rely on enzymatic methods with limitations.
• There is a need for nonenzymatic, accurate, and stable glucose sensors for subcutaneous tissue.

Purpose of the Study:

• To develop and evaluate a nonenzymatic sensor for glucose monitoring in subcutaneous tissue.
• To assess the performance of a viscometric-affinity sensor based on glucose-dependent viscosity.
• To compare sensor readings with capillary blood glucose concentrations in human trials.

Main Methods:

• A continuously working affinity sensor was designed using a microdialysis probe, flow-resisting capillaries, and pressure transducers.
• The sensor utilizes the glucose-dependent viscosity of a dextran and concanavalin A solution.
• Preliminary human trials involved subcutaneous implantation and comparison with capillary blood glucose levels.

Main Results:

• The viscometric sensor demonstrated linear and long-term stable glucose concentration dependence in vitro without drift.
• In vivo, sensor read-out followed capillary blood glucose dynamics with a 10-15 minute time-shift after appropriate calibration.
• The sensor maintained sensitivity for up to 44 hours and showed good coincidence with capillary blood glucose levels.

Conclusions:

• The viscometric-affinity sensor is an effective tool for subcutaneous glucose monitoring research.
• The sensor shows potential for further development into a clinically useful device for routine diabetes management.
• Nonenzymatic sensing offers a promising alternative for future glucose monitoring technologies.