Amperometric electrochemical sensor and method for manufacturing same

An amperometric electrochemical sensor with a fixed potential for measuring the content of an oxidation reduction substance dissolved in a liquid, said amperometric electrochemical sensor comprising:

• an insulating substrate,
• a set of electrodes, the set of electrodes including a working electrode, a counter electrode and a reference electrode, the working electrode having a top surface with a periphery edge,
• at least one of said working electrode and counter electrode being located on a top surface of said insulating substrate, and
• an insulating layer comprising insulating material extending over the top surface of the insulating subtrate,
• the insulating layer covering said working electrode, wherein said insulating layer completely covers the periphery edge of the top surface of said working electrode,
• wherein said insulating layer comprises plural openings exposing portions of the top surface of said working electrode, said openings being separated by small islands of the insulating material located on the top surface of said working electrode, and
• wherein the portions of the top surface of the working electrode exposed by said openings and the small islands on the working electrode are completely covered with at least a first polymer filtration membrane, the first polymer filtration membrane having a selectivity to said dissolved oxidation reduction substance to be measured and defining a diffusion layer for said oxidation reduction substance.

An amperometric electrochemical sensor with a fixed potential for measuring the content of an oxidation reduction substance dissolved in a liquid, said amperometric electrochemical sensor comprising:

• an insulating substrate having a top surface;
• a first insulating layer contactingly covering the top surface of the insulating substrate;
• a working electrode located in contact with an upper surface of said first insulating layer;
• a counter electrode located in contact with the upper surface of said first insulating layer and spaced apart from said working electrode,
• the working electrode and the counter electrode each having a top surface with a periphery edge;
• a second insulating layer extending over the top surface of the insulating substrate and completely covering at least the periphery edges of the top surface of said working electrode and said counter electrode,
• wherein said second insulating layer comprises plural openings exposing portions of the top surface of said working electrode and said counter electrode, said openings being separated by small islands of the insulating layer located on the top surface of said working electrode and the counter electrode, the openings being microscopic or nanoscopic, and
• wherein the portions of the top surface of the working electrode and the counter electrode exposed by said openings define active surfaces of the working electrode and the counter electrode, and at least one of said islands is located on the top surface of, and at a center of, said working electrode;
• and
• a first polymer membrane completely covering the openings located on the top surface of the working electrode, the first polymer membrane extending over and overhanging on an entire peripheral zone of the first insulating layer that covers the periphery edge of the top surface of said working electrode, the first polymer filtration membrane having a selectivity to said dissolved oxidation reduction substance to be measured and defining a diffusion layer for said oxidation reduction substance.

An amperometric electrochemical sensor with a fixed potential for measuring the content of an oxidation reduction substance dissolved in a liquid, said amperometric electrochemical sensor comprising:

• an insulating substrate having a top surface;
• a working electrode located over an upper surface of said insulating substrate;
• a counter electrode located in contact with the upper surface of said first insulating layer and spaced apart from said working electrode,
• the working electrode and the counter electrode each having a top surface with a periphery edge;
• an insulating layer extending over the top surface of the insulating substrate and completely covering at least the periphery edge of the top surface of said working electrode,
• wherein said insulating layer comprises plural openings exposing portions of the top surface of said working electrode, said openings being separated by small islands of the insulating layer located on the top surface of said working electrode, and
• wherein the portions of the top surface of the working electrode exposed by said openings define active surfaces of the working electrode, and at least one of said islands is located on the top surface of said working electrode and spaced apart from the periphery edge of the top surface of said working electrode;
• and
• a first polymer membrane completely covering the openings located on the top surface of the working electrode, the first polymer membrane extending over and overhanging on an entire peripheral zone of the first insulating layer that covers the periphery edge of the top surface of said working electrode, the first polymer filtration membrane having a selectivity to said dissolved oxidation reduction substance to be measured and defining a diffusion layer for said oxidation reduction substance.