An electrochemical test sensor for detecting the concentration of an analyte in a sample. The electrochemical test sensor comprises a base that provides a flow path for the fluid test sample having a counter electrode and a working electrode on its surface in electrical communication with a detector of electrical current. The electrochemical test sensor further includes a reagent layer directly located on the surface of the working electrode. The reagent layer includes an enzyme that is adapted to react with the analyte. The electrochemical test sensor further comprises a lid adapted to mate with the base and to assist in forming a capillary space with an opening for the introduction of the sample thereto. The capillary space is formed with a three-dimensional portion of the lid.