An implantable biosensor, which comprises a measuring (or first) chamber filled with the test fluid, which is able to convert a change of the concentration of a predetermined analyte or ion type into a change of a physical variable. To this end, the measuring chamber is closed by at least one membrane, which is permeable to the analyte or ion type and impermeable to the test fluid. In addition, the biosensor is equipped with at least one microacoustic sensor, which is operatively connected to the test fluid such that it can detect the physical variable that changes with the concentration of the analyte or ion type. Further relates to a sensor arrangement comprising at least one such implantable biosensor, the arrangement including a polling system that is wirelessly coupled to the biosensor.
