Patent ID: 8377378

Claim:
A sensor for determining the concentration of an analyte in a sample fluid, the sensor comprising: a first substrate having a proximal end and a distal end, the first substrate defining a first side edge and a second side edge of the electrochemical sensor extending from the proximal end to the distal end of the first substrate, the distal end being configured and arranged for insertion into a sensor reader; a working electrode and a counter electrode, wherein the working electrode and counter electrode are separated by an effective distance in a range of 25 to 1000 μm, wherein the working electrode or the counter electrode is formed from a molded carbon fiber composite or comprises an inert non-conducting base material upon which a conducting layer is deposited selected from the group consisting of: gold, carbon, platinum, ruthenium dioxide, palladium, and conductive epoxies; a second substrate disposed over the first substrate, the working electrode being disposed on one of the first and second substrates and the counter electrode being disposed on one of the first and second substrates; a spacer disposed between the first and second substrates and defining a first aperture and a second aperture, wherein the second aperture is defined along the second side edge; a sample chamber extending from the first aperture to the second aperture for holding the sample fluid, the sample chamber comprising the working electrode and the counter electrode, wherein the sample chamber is sized to contain a volume of no more than about IL of the sample; an analyte-responsive enzyme and a redox mediator disposed in the sample chamber; and a first indicator electrode disposed on at least one of the first and second substrates and positioned to determine when the sample chamber contains sample.