A Microdialysis probe coupled with a miniaturized thermal glucose sensor for in vivo monitoring

A miniaturized thermal flow injection analysis biosensor has been coupled with a microdialysis probe for continuous subcutaneous glucose monitoring. Thermal biosensors are based on the principle of measuring the heat evolved during enzyme catalysed reactions. The system presented here consists of a miniaturized thermal biosensor with a small column containing coimmibolized glucose oxidase and catalase. The analysis buffer passes through the column at a flow rate of 60μL/min via an 1μL sample loop which is connected to a microdialysis probe. Invitro results showed constant permeability of the probe and stability of the biosensor response during 24 hours. The response time was 85 sec giving a sample rate of 42 samples/hour. During a load experiment, the glucose profile in a healthy volunteer was followed both in the subcutaneous tissue and blood using the microdialysis set-up proposed and comparing to blood glucose analyser