Analyte sensors and methods of use
Analyte sensors for determining the concentration of an analyte in a sample. The sensors have a sample chamber having an inlet with a projection extending from an edge of the sensor for facilitating flow of sample into the sample chamber.
1. A sensor for determining the concentration of an analyte in a sample, the sensor comprising:
a first substrate and a second substrate;
a spacer between the first substrate and the second substrate;
a sample chamber having a first inlet and a second inlet, the first inlet and the second inlet defined by the first substrate, second substrate, and spacer; and
a first projection extending from a first edge of the sensor proximate the first inlet, wherein the first projection is defined by the first substrate, and wherein a width of the first projection is less than a width of the inlet.
2. The sensor of claim 1 , wherein the width of the projection is 80% or less than the width of the inlet.
3. The sensor of claim 1 , the width of the projection is approximately 50% of the width of the inlet.
4. The sensor of claim 1 , wherein the projection has a height of at least 0.2 mm.
5. The sensor of claim 1 , wherein the projection extends from a side edge of the sensor.
6. The sensor of claim 1 , wherein the sample chamber has a volume of one microliter or less.
7. The sensor of claim 1 , wherein the analyte is glucose and the sample chamber comprises a glucose-responsive enzyme.
8. The sensor of claim 1 , wherein the analyte is ketone and the sample chamber comprises a ketone-responsive enzyme.
9. The sensor of claim 1 , comprising:
a second projection extending from the first edge of the sensor proximate the first inlet, wherein the second projection is defined by the second substrate, and wherein a width of the second projection is less than a width of the inlet.
10. The sensor of claim 1 , comprising:
a second projection extending from a second edge of the sensor proximate the second inlet, wherein the second projection is defined by the first substrate, and wherein a width of the second projection is less than a width of the inlet.
11. The sensor of claim 1 , comprising:
a second projection extending from a second edge of the sensor proximate the second inlet, wherein the second projection is defined by the second substrate, and wherein a width of the second projection is less than a width of the inlet.
12. A sensor for determining the concentration of an analyte in a sample, the sensor comprising:
a first substrate and a second substrate;
a spacer between the first substrate and the second substrate; and
a sample chamber between the first substrate and the second substrate, wherein the sample chamber is bounded by the spacer, and wherein the sample chamber includes a first inlet and a second inlet;
a first projection extending from the first substrate at the first inlet; and
a second projection extending from the first substrate at the second inlet.
13. The sensor of claim 12 , comprising:
a third projection extending from the second substrate at the first inlet.
14. The sensor of claim 13 , comprising:
a fourth projection extending from the second substrate at the second inlet.
15. The sensor of claim 12 , wherein the analyte is glucose and the sample chamber comprises a glucose-responsive enzyme.
16. The sensor of claim 12 , wherein the analyte is ketone and the sample chamber comprises a ketone-responsive enzyme.
17. A sensor for determining the concentration of an analyte in a sample, the sensor comprising:
a first substrate and a second substrate;
a first side edge, a second side edge and an end edge;
a sample chamber defined between the first substrate and the second substrate, the sample chamber extending from the first side edge to the second side edge;
a first aperture between the first substrate and the second substrate at the first side edge;
a second aperture between the first substrate and the second substrate at the second side edge; and
a first projection extending from the first side edge proximate the first aperture.
18. The sensor of claim 17 , comprising:
a second projection extending from the second side edge proximate the second aperture.
19. The sensor of claim 18 , comprising:
a third projection extending from the first side edge proximate the first aperture; and
a fourth projection extending from the second side edge proximate the second aperture.
20. The sensor of claim 19 , wherein a width of the first projection is less than a width of the first aperture; a width of the second projection is less than a width of the second aperture; a width of the third projection is less than the width of the first aperture; and a width of the fourth projection is less than the width of the second aperture.
21. The sensor of claim 19 , wherein a width of the first projection is 80% or less than a width of the first aperture; a width of the second projection is 80% or less than a width of the second aperture; a width of the third projection is 80% or less than the width of the first aperture; and a width of the fourth projection is 80% or less than the width of the second aperture.
22. The sensor of claim 19 , wherein each of the first projection, second projection, third projection, and fourth projection have a height of at least 0.2 mm.
23. The sensor of claim 19 , wherein the first projection, second projection, third projection, and fourth projection are triangles extending from the substrates.
24. The sensor of claim 17 , wherein the analyte is glucose and the sample chamber comprises a glucose-responsive enzyme.
25. The sensor of claim 17 , wherein the analyte is ketone and the sample chamber comprises a ketone-responsive enzyme.
26. A method of analyzing an analyte concentration in a sample, comprising:
contacting a sample with a sensor, the sensor comprising:
a first substrate and a second substrate;
a spacer between the first substrate and the second substrate;
a sample chamber between the first substrate and the second substrate, wherein the sample chamber is bounded by the spacer, and wherein the sample chamber includes a first inlet and a second inlet;
a first projection extending from the first substrate at the first inlet; and
a second projection extending from the first substrate at the second inlet;
transferring the sample into the sample chamber through the first inlet, wherein the first inlet is bounded by the first substrate, the second substrate, and the first projection; and
determining the concentration of the analyte in the sample.
27. The method of claim 26 , wherein the first inlet is also bounded by a third projection.
28. The method of claim 26 , wherein the determining of the concentration of the analyte in the sample comprises employing one of coulometry, amperometry and potentiometry.
29. The method according to claim 28 , wherein the determining of the concentration of the analyte in the sample comprises employing coulometry.
30. The method of claim 26 , wherein the transferring of the sample into the sample chamber comprises transferring 1 μL or less of the sample into the sample chamber.
31. The method according to claim 26 , wherein the transferring of the sample into the sample chamber comprises transferring 0.5 μL or less of the sample into the sample chamber.
32. The sensor of claim 26 , wherein the analyte is glucose and the sample chamber comprises a glucose-responsive enzyme.
33. The sensor of claim 26 , wherein the analyte is ketone and the sample chamber comprises a ketone-responsive enzyme.
34. A method of analyzing an analyte concentration in a sample, comprising:
contacting a sample with a sensor, the sensor comprising:
a first substrate and a second substrate;
a spacer between the first substrate and the second substrate;
a sample chamber having a first inlet and a second inlet, the first inlet and the second inlet defined by the first substrate, second substrate, and spacer; and
a first projection extending from a first edge of the sensor proximate the first inlet, wherein the first projection is defined by the first substrate, and wherein a width of the first projection is less than a width of the inlet;
transferring the sample into the sample chamber through the first inlet, wherein the first inlet is bounded by the first substrate, the second substrate, and the first projection; and
determining the concentration of the analyte in the sample.
35. The method of claim 34 , wherein the sensor comprises a second projection extending from the first edge of the sensor proximate the first inlet, wherein the second projection is defined by the second substrate, and wherein a width of the second projection is less than a width of the inlet.
36. The method of claim 34 , wherein the determining of the concentration of the analyte in the sample comprises employing one of coulometry, amperometry and potentiometry.
37. The method according to claim 36 , wherein the determining of the concentration of the analyte in the sample comprises employing coulometry.
38. The method of claim 34 , wherein the transferring of the sample into the sample chamber comprises transferring 1 μL or less of the sample into the sample chamber.
39. The method according to claim 34 , wherein the transferring of the sample into the sample chamber comprises transferring 0.5 μL or less of the sample into the sample chamber.
40. The sensor of claim 34 , wherein the analyte is glucose and the sample chamber comprises a glucose-responsive enzyme.
41. The sensor of claim 34 , wherein the analyte is ketone and the sample chamber comprises a ketone-responsive enzyme.