Abstract: Provided is an electrochemical biosensor for the detection of at least one analyte dissolved in an analyte solvent, including a capillary detection space and a plurality of electrodes, wherein the plurality of electrodes includes at least one working electrode having a measuring region positioned in the capillary detection space, which is provided with an immobile detection agent for interacting with the analyte, and wherein the plurality of electrodes further includes a counter electrode extending into the capillary detection space, and wherein the plurality of electrodes is electrically contactable outside the capillary detection space, wherein the capillary detection space has a volume in a range of ?10 ?l, wherein an oxygen-binding or oxygen-reactive inerting agent is further provided in the capillary detection space, which is positioned at least partially between the working electrode and an inlet opening of the capillary detection space.