IN-VIVO CONTINUOUS MONITORING OF L-LACTATE COUPLING SUBCUTANEOUS MICRODIALYSIS AND AN ELECTROCHEMICAL BIOCELL

The microdialysis technique and a flow-through cell assembled with a lactate amperometric sensor have been coupled for continuous monitoring of lactate in subcutaneous tissue. Different fiber lengths and different flow rates have been tested to optimize the performance of the analytical system. The lactate probe is prepared by placing a nylon net membrane with immobilized lactate oxidase onto the platinum electrode inserted into the cell. Probe stability and reproducibility have been optimized. The response time of the biosensor is less than two minutes. In vivo experiments based on four hour continuous lactate monitoring on a rabbit showed good sensor stability and reproducibility. The same experiments on human volunteers showed a lactate increase during physical exercise. Compared with a reference spectrophotometric procedure, the results correlated well.