Patent ID: 8083929

Claim:
A sensor for determining the concentration of glucose in a sample fluid, the sensor comprising: a working electrode disposed on a first substrate and a counter/reference electrode disposed on a second substrate, wherein the working electrode comprises palladium and the counter/reference electrode comprises gold, and wherein the working electrode and the counter/reference electrode are in a facing configuration and separated by an effective distance in a range of 25 to 1000 μm; 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 a first side edge of the sensor and a second aperture along a second side edge of the sensor, wherein either the first aperture or the second aperture is 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 sample, 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 a glucose dehydrogenase and a diffusible redox mediator comprising ferricyanide disposed in the sample chamber; wherein the first and second substrates define a sensor comprising a proximal end having a width and a distal end having a width, the distal end being configured for insertion into a sensor reader, wherein the width of the distal end is greater than the width of the proximal end.