Development and Characterization of Choline and L-Glutamate Biosensor Integrated on Silicon Microprobes for In-Vivo Monitoring

A silicon microprobe to measure in real-time choline and L-glutamate in brain tissue is described. The biosensors are prepared by coating integrated platinum thin-film electrodes with an enzymatic membrane by electrochemically aided deposition. This method allows a very local and reproducible immobilization of the enzymes and the achievement of high sensitivities as required for in vivo recordings. Moreover, several closely-spaced electrode sites on the same microprobe can be coated with different enzyme membranes without any cross-contamination.