Patent ID: 8083928

Claim:
A sensor for determining the concentration of an analyte in a sample fluid, the sensor comprising: an electrode pair comprising a first electrode and a second electrode, wherein the first electrode and second electrode are separated by an effective distance in a range of 25 to 1000 μm; 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 second substrate disposed over the first substrate, the first electrode being disposed on the first substrate and the second electrode being disposed on the second substrate; a spacer comprising a first part and a second part disposed between the first and second substrates, wherein the first part of the spacer, the second part of the spacer, the first substrate, and the second substrate define a first aperture along the first side edge of the sensor and a second aperture along the second side edge of the sensor, wherein either the first aperture or the second aperture are used for sample application and the sensor has no more than two apertures; a sample chamber for holding the sample fluid and sized to contain a volume of no more than about 1 μL of the sample fluid, wherein the sample chamber has a length which extends from the first aperture to the second aperture and a substantially uniform width between the first part of the spacer and the second part of the spacer along the entire length of the sample chamber, and wherein the width of the sample chamber is not wider than either the first aperture or the second aperture; and an analyte-responsive enzyme and a diffusible redox mediator disposed in the sample chamber.