METHOD AND REAGENT FOR PRODUCING NARROW, HOMOGENOUS REAGENT STRIPS

• US 20090162532A1
• Filed: 01/29/2009
• Published: 06/25/2009
• Est. Priority Date: 06/20/2003
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Operations Limited (Roche Holding AG)
• Inventors: Mosoiu, Dan, Wilsey, Christopher D.
• Granted Patent: US 7,879,618 B2
• Time in Patent Office: Days
• US Class Current: 427/2.130
• CPC Class Codes: G01N 27/3271 Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood amperometry per se G01N27/49; aspects concerning the enzyme reagent C12Q1/001
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: Y10T 156/1059 Splitting sheet lamina in plane intermediate of faces
• CPC Class Codes: Y10T 156/1084 of continuous or running length bonded web

Abstract

The present invention concerns a reagent coating mass which can be used in slot-die-coating of flat support materials in the manufacturing processes of test strips. Advantageously, the reagent mass of the invention exhibits certain superior rheological properties such as viscosity, surface tension and thixotropy. The reagent mass is preferably used to coat thin, narrow and homogeneous stripes of reagent material onto flat web material.

Claims

1. A process for producing a reagent layer on a solid support material, comprising the steps of:

providing a solid support material;

moving said solid support material relative to a slot-die-coating head;

maintaining a defined distance between the surface of said solid support material and said slot-die-coating head;

depositing a shear thinning, at least slightly thixotropic reagent through said slot-die-coating head to create a continuous stripe of reagent on said solid support material, wherein said reagent has a viscosity of between about 70 and 130 mPa-s and a surface tension of between about 30 and 50 mN/m; and

drying the coated reagent stripe on said support material.

2. The process according to claim 1, wherein said reagent is deposited on said solid support at a coating flux rate of about 5.5 to about 30 g/min.

3. The process according to claim 1, wherein said reagent is deposited on said solid support at a coating flux rate of about 13 to about 15 g/min.

4. The process according to claim 1, wherein said defined distance between said slot-die-coating head and said support material is between 30 and 90 μ

m.

5. The process according to claim 1, wherein said support material moves relative to said slot-die-coating head at a rate of between 20 and 80 m/min.

6. The process according to claim 1, wherein said support material moves relative to said slot-die-coating head at a rate of between 30 and 40 m/min.

7. The process according to claim 1, wherein said stripe of reagent is less than 1 cm wide.

8. The process according to claim 1, wherein after drying, said reagent on said solid support material has a height of less than 10 μ

m.

9. The process according to claim 1, said reagent including at least one of buffers, enzymes, mediators, stabilizers, thickeners, proteins, indicators, dyes, film formers, surfactants and co-factors.

10. The process according to claim 9, said reagent further including at least one of silica, xanthan gum and CMC.

11. The process according to claim 9, said reagent further including silica and at least one of xanthan gum and CMC.

12. The process according to claim 9, said reagent further including silica, xanthan gum and CMC.

13. In a process for preparing biosensors from a webbing of a substrate, the improvement comprising:

depositing a continuous stripe of reagent onto the webbing in the form of a shear thinning, at least slightly thixotropic reagent having a viscosity of between about 70 and 130 mPa-s and a surface tension of between about 30 and 50 mN/m; and

drying the coated reagent stripe on said support material.

14. A process for preparing biosensors comprising:

depositing a continuous stripe of reagent onto a webbing in the form of a shear thinning, at least slightly thixotropic reagent having a viscosity of between about 70 and 130 mPa-s and a surface tension of between about 30 and 50 mN/m;

applying a spacer layer over the reagent; and

attaching the spacer layer to the webbing.