Modeling the response time of an in vivo glucose affinity sensor

Area of Science:

• Biomedical Engineering
• Chemical Engineering
• Analytical Chemistry

Background:

• Optical glucose sensors rely on competitive displacement assays for glucose detection.
• Fluorescent lifetime measurements track ligand-receptor interactions.
• Hollow fiber membranes are used to encapsulate sensor components.

Purpose of the Study:

• To develop a mathematical model for an optical glucose sensor's dose-response relationship.
• To predict sensor response time under various conditions.
• To investigate the impact of environmental factors on sensor performance.

Main Methods:

• Developed a numerical model incorporating glucose diffusion and displacement reactions.
• Simulated the effect of external mass transfer boundary layers.
• Analyzed parametric sensitivity, focusing on glucose diffusion coefficients.
• Modeled the influence of a fibrotic capsule layer.

Main Results:

• External mass transfer boundary layers increased response time by 3.7-fold.
• Sensor response time is most sensitive to the glucose diffusion coefficient in the membrane.
• Model predictions were shorter than experimental data for an intensity-based sensor.
• A fibrotic capsule layer increased response time by 5-fold.

Conclusions:

• Mathematical modeling provides insights into optical glucose sensor kinetics.
• Diffusion limitations and in vivo encapsulation significantly impact sensor response time.
• Further model refinement is needed to match experimental observations.