a biochip includes a flat carrier and an array of spots containing catcher molecules which are arranged on the carrier . each spot is associated with a microelectrode arrangement for impedance spectroscopic detection of binding events occurring between the catcher molecules and the target molecules applied via an analyte solution . in order to increase the sensitivity or the binding - specific measuring effects of the bio - chip , the electrode arrangement is at least partially embedded in a hydrophilic reaction layer containing catcher molecules and which is permeable to target molecules .