A MEMS affinity glucose sensor using a biocompatible glucose-responsive polymer.

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Diabetes management requires accurate, long-term glucose monitoring.
• Current continuous glucose monitoring (CGM) methods face challenges with accuracy, invasiveness, and longevity.
• Novel sensing technologies are needed to improve diabetes care.

Purpose of the Study:

• To develop and characterize a MEMS affinity sensor for continuous glucose monitoring in subcutaneous tissue.
• To utilize changes in solution viscosity, detected via microcantilever vibrations, as a glucose sensing mechanism.
• To evaluate the sensor's performance in terms of sensitivity, response time, reversibility, and stability.

Main Methods:

• Fabrication of a MEMS device with a magnetically driven vibrating microcantilever made of Parylene.
• Utilizing a microchamber filled with a biocompatible, glucose-specific polymer (poly(acrylamide-ran-3-acrylamidophenylboronic acid)).
• Measuring damped cantilever vibrations via an optical lever setup to determine glucose concentration based on viscosity changes.

Main Results:

• The sensor successfully detected glucose in physiologically relevant concentrations (27 mg/dL to 324 mg/dL).
• A glucose response time constant of approximately 3 minutes was achieved.
• The sensor demonstrated excellent reversibility and stability, crucial for long-term monitoring.

Conclusions:

• The developed MEMS affinity sensor shows significant potential for long-term, continuous glucose monitoring in diabetes management.
• The viscosity-based sensing principle offers a promising alternative for accurate and stable glucose detection.
• Further optimization of the device design could lead to improved response times and enhanced performance for clinical applications.