Biosensor

• US 6,755,949 B1
• Filed: 10/09/2001
• Issued: 06/29/2004
• Est. Priority Date: 10/09/2001
• Status: Expired due to Term

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Corporation (Roche Holding AG)
• Inventors: Bhullar, Raghbir S., Wilsey, Christopher D., Austera, John T.
• Primary Examiner(s): Noguerola, Alex
• Application Number:
  US09/974,434
• Publication Number:
  US 20040108206A1
• Time in Patent Office: 994 Days
• Field of Search: 204/403.01, 204/416, 204/409, 422/99, 422/50, 422/58, 422/55, 422/70, 422/82-1-
• US Class Current: 204/409
• CPC Class Codes: C12Q 1/004 mediator-assisted
• 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: Y10T 29/49002 Electrical device making

Abstract

A biosensor is provided in accordance with the present invention. The biosensor includes a substrate and a cover extending across at least a portion of the substrate. The cover includes a first surface facing the substrate and a second surface. At least a portion of the first surface is removed to define a capillary channel. The capillary channel has a surface energy ranging from about 60 mN/m to about 72 mN/m.

Claims

1. A biosensor comprising:

a substrate,

a cover extending across at least a portion of the substrate, the cover including a first surface facing the substrate and a second surface, a capillary channel being defined in at least a portion of the first surface, the capillary channel having a surface energy ranging from about 60 mN/m to about 72 mN/m, and

at least one microstructure including a fixed end coupled to either the substrate or the cover and an opposite free end exposed in the capillary channel, wherein the free end of each microstructure has an exposed metallic coating.

2. The biosensor of claim 1 wherein the first surface is formed to include the at least one microstructure extending into the channel.

3. The biosensor of claim 2 wherein at least one of the microstructures has a round post-like shape.

4. The biosensor of claim 2 wherein at least one of the microstructures has a generally square post-like shape.

5. The biosensor of claim 2 wherein the capillary channel includes opposite ends and the first surface is formed to include at least two microstructures that include a front side facing one end and a back side facing the opposite end and opposite inner and outer edges that extend between the front and back sides.

6. The biosensor of claim 5 wherein the front side and the back side of the at least two microstructures each have a greater dimension than the inner and outer edges.

7. The biosensor of claim 6 wherein the metallic coating is gold.

8. The biosensor of claim 1 wherein the first surface includes spaced-apart secondary capillary recesses.

9. The biosensor of claim 1 wherein at least a portion of the first surface includes a metallic coating.

10. A biosensor comprising:

a capillary path defined between a substrate and a cover, the path having a surface energy ranging from about 60 mN/m to about 72 mN/m,

electrodes positioned on the substrate, and

at least one microstructure positioned in the capillary path, the at least one microstructure including a fixed end coupled to either the substrate or the cover and an opposite free end, wherein the free end of each microstructure has an exposed metallic coating.

11. The biosensor of claim 10 wherein the capillary path has a surface energy ranging from about 60 mN/m to about 72 mN/m.

12. The biosensor of claim 10 wherein the free end is coated with a metal selected from the group consisting of gold, platinum, palladium, and iridium.

13. The biosensor of claim 12 wherein the metal is gold.

14. The biosensor of claim 10 wherein at least one of the microstructures has a round post-like shape.

15. The biosensor of claim 10 wherein at least one of the microstructures has a generally square post-like shape.

16. A biosensor comprising:

a substrate,

electrodes positioned on the substrate,

a cover extending across at least a portion of the substrate to define a capillary path, and

at least one microstructure positioned in the capillary path, the at least one microstructure including a fixed end coupled to the cover and an opposite free end, wherein the free end of each microstructure has an exposed metallic coating.

17. The biosensor of claim 16 wherein the free end formed of a metal selected from the group consisting of gold, platinum, palladium, and iridium.

18. The biosensor of claim 16 wherein the metal is gold.

19. The biosensor of claim 16 wherein the microstructures have a surface energy ranging from about 60 mN/m to about 72 mN/m.

20. A method of forming a biosensor, the method comprising the steps of:

providing a substrate, a reagent for the measurement of at least one analyte, and a cover, the cover including a first surface,

exposing the cover to at least one pulse of light ablating the first surface in a pre-determined pattern creating a channel,

forming electrodes on the substrate, wherein the forming step includes exposing the substrate to at least one pulse of light sufficient to ablate a portion of the substrate about the electrodes;

cleaning the first surface of the cover so that the surface energy of the channel ranges from about 60 mN/m to about 72 mN/m,

positioning the reagent upon the substrate, and

placing the first surface of the cover upon the substrate to define a capillary path and the reagent is positioned in the capillary path.

21. The method of claim 20 wherein the first surface is cleaned by a microwave plasma machine.

22. The method of claim 20 wherein the first surface is ablated to create microstructures in the channel.

23. The method of claim 20 further comprising the step of exposing the substrate to at least an additional pulse of light sufficient to ablate a portion of the substrate creating at lest one microstructure extending from the substrate.

24. The method of claim 20 further comprising the step of cleaning the substrate to increase the surface energy of the substrate.

25. The method of claim 20 further comprising the steps of positioning a mask having a pre-defined pattern over the first surface and exposing the mask and the cover to at least one pulse of light sufficient to ablate the exposed surface of the cover creating at least one microstructure extending from the cover.