Implantable Silicon Microsensors for the Diagnosis of Neurological Disease
A silicon/polymer micro-needle including three Pt electrodes, one reference and two working electrodes grafted with specific enzymes, constitutes the implantable part of the device. In the presence of biomolecules to be detected, reactions with the specific enzymes produce hydrogen peroxide (H2O2) which is oxidized onto Pt with the transfer of 2 e- and the release of 2 protons in the solution. These electrons induce an amperometric response proportional to the concentration of the molecule to be detected.
In vitro assays have revealed excellent sensitivity and selectivity of the device, which has been further confirmed by in vivo assays in rat brain demonstrating the simultaneous detection of the lactate and glucose levels upon insulin administration. This new and efficient device opens very exciting perspectives for the study of complex neurochemical mechanisms in the central nervous systems and for the diagnosis of neurological diseases.