This invention relates to a biosensor and more particularly to an electrochemical biosensor for determining the concentration of an analyte in a carrier. The mask structure includes a first and second hard mask structures separated by an image transfer layer, such as DURAMIDE\xae. A flow of partially solvated ions is transported along a tortuous path into a region of disturbance of flow, where ions and neutral molecules collide and mix. The guiding pin being forced into the transverse hole of the guiding spindle of the suction cup is guided directly along guiding grooves or cam surfaces inside the housing of the suction cup.