Abstract: The present invention relates to a lab-on-a-chip version of biosensor for an on-the-spot analysis whose analytical performances were remarkably improved, by incorporating commercial membranes, traditionally used for rapid diagnostics, into microfluidic channels engraved on the surface of a plastic chip, as follows: 1) reduction of sample size; 2) realization of variable functions for total analysis; and 3) transfer of medium by capillary action without the assistance of an external force.