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 l actate amperometric sensor have been coupled for continuous monitoring of lactate in subcutaneous tissue. Different fiber lengths and differ ent flow rates have been tested to optimize the performance of the ana lytical system. The lactate probe is prepared by placing a nylon net m embrane with immobilized lactate oxidase onto the platinum electrode i nserted into the cell. Probe stability and reproducibility have been o ptimized. 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 phys ical exercise. Compared with a reference spectrophotometric procedure, the results correlated well.