Devices and methods relating to electrochemical biosensors

A diagnostic strip for measuring the concentration of an analyte in a bodily fluid, the test strip defining a capillary passageway, the passageway being dimensioned so as to induce movement of a sample of bodily fluid along a predetermined path through the passageway extending inwardly from an entrance at an edge of the test strip, comprising:

• a first electrode pair, comprising a first electrode and a second electrode, operating in a first substantially planar physical zone, the first electrode and the second electrode each including a plurality of fingers, the fingers of the first electrode and the second electrode being interdigitated and being separated from their nearest adjacent fingers by at most 50 μm at their nearest points;
• a second electrode pair, comprising a third electrode and a fourth electrode, operating in a second substantially planar physical zone that is substantially co-planar with the first planar physical zone, the third electrode and the fourth electrode each including at least one finger, the fingers of the third electrode and the fourth electrode each being separated from their nearest adjacent fingers by greater than 50 μm;
• and
• a reagent located within the capillary passageway, the reagent combining with the bodily fluid to produce a redox reaction,
• said reagent being located over at least one of the first and second sets of electrodes, and
• the other of the first and second sets of electrodes either having said reagent located thereover or having no reagent located thereover.

A test strip for measuring the concentration of an analyte in a bodily fluid, the test strip defining a capillary passageway dimensioned so as to induce movement of a sample of bodily fluid along a predetermined path through the passageway extending inwardly from an entrance, the test strip comprising:

• a first set of electrodes in electrical communication with the passageway, the first set of electrodes including a pair of electrodes with interdigitated fingers, wherein adjacent fingers are separated from one another by a gap;
• a second set of electrodes in electrical communication with the passageway, the second set of electrodes including a pair of electrodes with interdigitated fingers, wherein adjacent fingers are separated from one another by a gap, with the gap between adjacent electrode fingers of the second electrode set being larger than the gap between adjacent electrode fingers of the first electrode set;
• and
• a reagent located within the capillary passageway, the reagent combining with the bodily fluid to produce a redox reaction,
• said reagent being located over at least one of the first and second sets of electrodes, and
• the other of the first and second sets of electrodes either having said reagent located thereover or having no reagent located thereover.