BIOSENSOR AND METHOD OF MAKING

• US 20090020502A1
• Filed: 09/25/2008
• Published: 01/22/2009
• Est. Priority Date: 10/04/1999
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Operations Limited (Roche Holding AG)
• Inventors: Diebold, Eric R., Hill, Brian S., Bhullar, Raghbir S., Walling, Paul Douglas, Surridge, Nigel
• Granted Patent: US 8,287,703 B2
• Time in Patent Office: Days
• US Class Current: 216/20
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: G01N 33/5438 Electrodes
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 3/027 the conductive material being removed by irradiation, e.g. by photons, alpha or beta particles
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49156 with selective destruction of conductive paths

Abstract

An electrochemical biosensor with electrode elements that possess smooth, high-quality edges. These smooth edges define gaps between electrodes, electrode traces and contact pads. Due to the remarkable edge smoothness achieved with the present invention, the gaps can be quite small, which provides marked advantages in terms of test accuracy, speed and the number of different functionalities that can be packed into a single biosensor. Further, the present invention provides a novel biosensor production method in which entire electrode patterns for the inventive biosensors can be formed all at one, in nanoseconds—without regard to the complexity of the electrode patterns or the amount of conductive material that must be ablated to form them.

Claims

1. A method of making a biosensor comprising the following steps:

providing a base substrate having a layer of electrically conductive material thereon;

removing a portion of the conductive material to form first and second electrode elements on the base substrate having first and second respective edges defining a gap therebetween, the gap having a width and a length;

the first edge being spaced from a first theoretical line by a first distance that varies along the length of the gap, the first theoretical line defining a desired shape and placement of the first edge, wherein the standard deviation of the first distance is less than about 6 μ

m over the entire length of the gap;

providing a reagent at least partially covering the base; and

adhering one or more layers to the base, the one or more layers cooperating to form a sample-receiving chamber and a cover for the biosensor, at least a portion of the reagent and an electrode being positioned within the chamber.

2. The method of claim 1, further comprising removing at least 10% of the conductive material.

3. The method of claim 1, further comprising removing at least 50% of the conductive material.

4. The method of claim 1, further comprising removing at least 90% of the conductive material.

5. The method of claim 1, wherein the electrically conductive material is removed by broad field laser ablation.

6. The method of claim 1, wherein the first and second electrode elements comprise a first electrode set.

7. The method of claim 6, further comprising forming a second electrode set on the base substrate having a feature size different from the first electrode set, one of the electrodes of the first electrode set being the electrode positioned within the sample receiving chamber and one of the electrodes of the second electrode set being positioned in the sample receiving chamber.

8. The method of claim 1, wherein the standard deviation is less than about 2 μ

m.

9. The method of claim 1, wherein the standard deviation is less than about 1 μ

m.

10. The method of claim 1, further comprising forming the electrode elements in less than about 0.25 seconds.

11. The method of claim 1, further comprising forming the electrode elements in less than about 50 nanoseconds.

12. The method of claim 1, further comprising forming the electrode elements in less than about 25 nanoseconds.

13. The method of claim 1, wherein the step of adhering the one or more layers to the base comprises laminating a spacing layer having a void that defines the perimeter of the sample receiving chamber over the base substrate and laminating a covering layer over the spacing layer.

14. The method of claim 13, further comprising forming a vent opening in the covering layer that communicates with the sample receiving chamber.

15. A method of forming a biosensor used to measure presence or concentration of an analyte in a fluid sample, comprising:

(a) providing an electrically conductive material on a base;

(b) removing a portion of the electrically conductive material by broad field laser ablation to form an electrode set on the base;

(c) providing a reagent at least partially covering the base; and

(d) adhering one or more layers to the base, the one or more layers cooperating to form a sample-receiving chamber and a cover for the biosensor, at least a portion of both the reagent layer and the electrode set being positioned in the chamber.

16. The method of claim 15, wherein the electrode set comprises first and second electrodes having first and second respective edges defining a gap therebetween, the gap having a width and a length, the first edge being spaced from a first theoretical line by a first distance that varies along the length of the gap, the first theoretical line defining a desired shape and placement of the first edge, wherein the standard deviation of the first distance is less than about 6 μ

m over the entire length of the gap.

17. The method of claim 16, wherein the standard deviation of the first distance is less than about 2 μ

m.

18. The method of claim 16, wherein the standard deviation of the first distance is less than about 1 μ

m.

19. The method of claim 16, wherein the electrode set comprises at least two electrode sets having different feature sizes.

20. The method of claim 15, wherein the electrode set comprises at least two electrode sets having different feature sizes.

21. The method of claim 15, wherein step (c) comprises at least partially covering the electrode set with the reagent.

22. The method of claim 15, further comprising removing at least 10% of the conductive material.

23. The method of claim 15, further comprising removing at least 50% of the conductive material.

24. The method of claim 15, further comprising removing at least 90% of the conductive material.

25. A method of forming a biosensor used to measure concentration of an analyte in a fluid sample, comprising:

(a) providing an electrically conductive material on a base;

(b) removing at least 10% of the electrically conductive material to form at least two electrode sets on the base, the electrode sets having different feature sizes;

(c) providing a reagent at least partially covering the base; and

(d) adhering one or more layers to the base, the one or more layers cooperating to form a sample-receiving chamber, at least a portion of one of the electrode sets being positioned in the chamber.

26. The method of claim 25, further comprising removing at least 50% of the conductive material.

27. The method of claim 25, further comprising removing at least 90% of the conductive material.

28. The method of claim 25, wherein the electrically conductive material is removed by broad field laser ablation.

29. The method of claim 25, wherein one of the electrode sets comprises first and second electrodes having first and second respective edges defining a gap therebetween, the gap having a width and a length, the first edge being spaced from a first theoretical line by a first distance that varies along the length of the gap, the first theoretical line defining a desired shape and placement of the first edge, wherein the standard deviation of the first distance is less than about 6 μ

m over the entire length of the gap.

30. The method of claim 29, wherein the standard deviation of the first distance is less than about 2 μ

m.

31. The method of claim 29, wherein the standard deviation of the first distance is less than about 1 μ

m.

32. The method of claim 25, wherein step (c) comprises at least partially covering the electrode set with the reagent.