The aim of subproject A05 is to improve the functionality of cochlear implants by employing the cochlear electrode as an electrically active implant itself as a detector, with additional coatings to detect changes in the electrochemical impedance at the perilymph interface. The clinical boundary conditions for validating the novel functionalization for the detection of platinum in the perilymph are to be determined and the additional detection of inflammation-induced proteins enabled. Moreover, the sensory cochlear electrode will be adapted for the detection of local dexamethasone concentrations, thereby providing the first approach for real-time, in-ear measurement of therapeutic agents.