Electrochemical sensor strip

An electrochemical sensor strip comprising:

• a housing including an electrode support and a cover plate, which cooperatively define a sample receiving space, an opening, and a sample passage connected to said opening and said sample receiving space, said electrode support having an inner surface confronting said cover plate, an outer surface opposite to said inner surface, an upstream recessed region formed in said inner surface to define said sample passage, and a downstream recessed region formed in said inner surface to define said sample receiving space, and a plurality of through holes extending through said inner and outer surfaces within said downstream recessed region;
• a plurality of electrodes disposed respectively in said through holes, at least one of said electrodes having a lowered top surface that is lowered relative to said inner surface to define a shallow space within a respective one of said through hole;
• a reaction reagent layer disposed in said sample receiving space in contact with said electrodes and extending into said shallow space;
• and
• a filter that is made of a material having a porous structure and that extends into said sample receiving space from said opening and through said sample passage, said filter covering a portion of said reaction reagent layer and extending above said shallow space and said lower top surface.