Multi-layered electrochemical microfluidic sensor comprising reagent on porous layer

A microfluidic assay apparatus for the detection of an analyte in a test solution, said microfluidic assay apparatus being a multi-layer body comprising:

• a) a first, polymer layer, said polymer layer having at least one fluidic connection comprising a microstructure with at least one electrode integrated at a given location along said microstructure and forming a detection portion, said microstructure further comprising at least one inlet and one outlet and said at least one integrated electrode being connected to an external electrochemical unit;
• b) a second, non-porous layer covering the microstructure so as to provide a sealed microstructure enabling microfluidic manipulations of a solution through said microstructure;
• c) a third, porous layer, selected from a membrane, a glass frit, a sol-gel or a combination thereof and placed in contact with said first polymer layer at the inlet and/or outlet of said microstructure, said third porous layer comprising an immobilized reagent, said reagent interacting with said test solution to form a product that is transported through the porous layer and is released out of the porous layer inside the microstructure before being further transported inside said microstructure, so as to enable the detection of said analyte by way of said at least one integrated electrode.