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.