Patent ID: 8372261

Claim:
A system for determining the concentration of an analyte in a sample fluid, the system comprising: (a) a sensor comprising: a first substrate having a proximal end and a distal end, the distal end being configured and arranged for insertion into a sensor reader; a second substrate disposed over the first substrate; a spacer disposed between the first and second substrates and defining a first aperture along the first side edge of the sensor, a second aperture along the second side edge of the sensor, and a sample chamber extending from the first aperture to the second aperture, wherein the sample chamber is sized to contain a volume of no more than about 1 μL of the sample; a working electrode and a counter electrode disposed in the sample chamber, wherein the working electrode and the counter electrode are separated by a closest distance in a range of from 200 to 1000 μm; and an analyte-responsive enzyme and a redox mediator disposed in the sample chamber; (b) a sensor reader configured to: apply a first potential and a second potential to determine fill of the sample chamber; apply a third potential to electrolyze the analyte, thereby generating an analyte signal; and determine the concentration of the analyte using the analyte signal.