Test element

• US 20060003397A1
• Filed: 02/18/2005
• Published: 01/05/2006
• Est. Priority Date: 02/18/2004
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Hoenes, Joachim, Horn, Carina, Knappe, Wolfgang-Reinhold, Wittmann, Franz, Mosoiu, Dan
• Granted Patent: US 7,629,175 B2
• Time in Patent Office: Days
• US Class Current: 435/14
• CPC Class Codes: C12Q 1/54 involving glucose or galactose
• CPC Class Codes: G01N 33/521 Single-layer analytical elements
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

The invention concerns test elements and methods for the optical detection of an analyte in a sample. The test element includes a support having at least one transparent portion, and a one-layer film positioned on the support. The film has a thickness when dry of less than about 10 μm. The method includes contacting the sample with the test element and determining the analyte concentration in the sample.

Claims

1. A test element for the optical detection of an analyte comprising:

a support having at least one transparent portion, and

a one-layer film positioned on the support, the film comprising a reagent for the detection of the analyte and having a thickness when dry about 10 μ

m or less.

2. The test element of claim 1 wherein the thickness of the film when dry is about 2 μ

m to about 10 μ

m.

3. The test element of claim 1 wherein the reagent comprises at least one enzyme and at least one enzyme substrate that can be detected after an enzymatic reaction with the analyte.

4. The test element of claim 1 wherein a concentration of the reagent in the film is such that the test element supports a generally uniform reaction with the analyte over the thickness of the test element.

6. The test element of claim 1 wherein the film is porous.

7. The test element of claim 6 wherein the pore size is such that penetration of erythrocytes into the film is generally excluded.

8. The test element of claim 1 wherein the film comprises pigment particles.

9. The test element of claim 8 wherein the pigment particles are based on TiO₂.

10. The test element of claim 8 wherein the pigment particles are based on ZrO₂.

11. The test element of claim 8 wherein the average diameter of the pigment particles is less than about 0.5 μ

m.

12. The test element of claim 8 wherein the average diameter of the pigment particles is between about 0.1 μ

m and about 0.3 μ

m.

13. The test element of claim 8 wherein the film comprises fine-grained pigment particles and medium or course grained particles, wherein the medium or course grained particles are selected from the group consisting of TiO₂, BaTiO₃, ZrO₂, ZrSiO₃ and BaSO₄.

14. The test element of claim 8 wherein the film comprises medium-grained or course-grained particles selected from the group consisting of SiO₂, a silicate, and a water-insoluble plastic.

15. The test element of claim 8 wherein the film comprises medium-grained particles with an average diameter of about 0.7 μ

m to about 4 μ

m.

16. The test element of claim 15 wherein the average diameter of the medium-grained particles is between about 1 μ

m and about 3 μ

m.

17. The test element of claim 8 wherein the film comprises course-grained particles with an average diameter of about 4 μ

m to about 8 μ

m.

18. The test element of claim 8 wherein the film comprises a mixture of fine-grained pigment particles and coarse-grained particles.

19. The test element of claim 18 wherein the mixture of fine-grained pigment particles and coarse-grained particles has a weight ratio of about 1:

0.2 to about 1;

1.

20. The test element of claim 8 wherein the film comprises a mixture of fine-grained pigment particles and medium-grained particles.

21. The test element of claim 20 wherein the mixture of fine-grained pigment particles and medium-grained particles has a weight ratio of about 1:

0.2 to about 1;

1.

22. The test element of claim 8 wherein the film comprises a mixture of fine-grained pigment particles, coarse-grained particles and medium-grained particles.

23. The test element of claim 8 wherein the film comprises a mixture of fine-grained pigment particles, coarse-grained particles and medium-grained particles in a weight ratio of about 1:

0.1;

0.9 to about 1;

0.1;

0.9.

24. The test element of claim 1 wherein the reagent is present in a polymer matrix.

25. The test element of claim 1 wherein the reagent is formed for the detection of NADH.

26. The test element of claim 1 wherein the reagent is formed for the reflection photometric detection of an analyte.

27. The test element of claim 1 wherein the reagent is formed for the reflection fluorimetric detection of an analyte.

28. The test element of claim 1 wherein the reagent is formed for the visible detection an analyte.

29. The test element of claim 1 wherein a reaction period for the detection of the analyte is less than about 5 seconds.

30. The test element of claim 1 wherein a reaction period for the detection of the analyte is about 1 second to about 4 seconds.

31. The test element of claim 1 wherein a reaction period for the detection of the analyte is about 2 seconds.

36. The test element of claim 27, wherein the test reagent comprises an enzyme system selected from the group consisting essentially of:

glucose dye oxidoreductase and

glucose dehydrogenase.

32. A test element for the optical detection of an analyte comprising:

a support having at least one transparent portion,

a one-layer film positioned on the support, the film comprising a reagent for the detection of the analyte and

wherein the test element is formed to determine the analyte within a reaction period of less than about 5 seconds.

33. A test element for the optical detection of an analyte comprising:

an at least partially optically essentially transparent support and

a one-layer reaction film comprising a test reagent for determining the analyte, wherein the thickness and porosity of the reaction film and the concentration of the test reagent are adjusted such that the analyte is determined within a reaction period of less than about 5 seconds with a signal intensity that is sufficient for a quantitative determination.

34. The test element of claim 33 wherein the reaction period is about 1 to about 4 seconds.

35. The test element of claim 33 wherein the reagent is suitable for the determination of an analyte selected from the group consisting of:

glucose, lactate, ketone bodies and urea.

37. A method for the detection of an analyte in a sample comprising the steps:

contacting the sample with the test element comprising a support having at least one transparent portion, and a one-layer film positioned on the support, the film comprising a reagent for the detection of the analyte and having a thickness when dry about 10 μ

m or less, and determining the analyte concentration in the sample.

38. The method of claim 37 wherein the determination is selected from the group consisting of:

reflection, photometric, or fluorimetric detection.

39. The method of claim 38 wherein the determination takes place within a reaction period of less than about 5 seconds.

40. The method of claim 38 wherein the determination takes place within a reaction period of about 1 to about 4 seconds.

41. The method of claim 38 wherein the analyte is glucose.