Color fixed chromogenic analytical element

• US 4,361,648 A
• Filed: 08/13/1981
• Issued: 11/30/1982
• Est. Priority Date: 08/13/1981
• Status: Expired due to Term

• Current Assignee: Miles Laboratories, Inc. (Bayer AG)
• Original Assignee: Miles Laboratories, Inc. (Bayer AG)
• Inventors: Shuenn-tzong, Chen
• Primary Examiner(s): Kepplinger, Esther M.
• Application Number:
  US06/292,345
• Time in Patent Office: 474 Days
• Field of Search: 435/10, 435/11, 435/14, 435/18, 435/19, 435/25, 435/26, 435/28, 435/805, 435/810, 23/230 B, 422/56
• US Class Current: 435/10
• CPC Class Codes: C12Q 1/28 involving peroxidase
• CPC Class Codes: C12Q 2326/12 3,3',5,5'-Tetramethylbenzidine, i.e. TMB
• CPC Class Codes: G01N 33/521 Single-layer analytical elements
• CPC Class Codes: Y10S 435/805 Test papers
• CPC Class Codes: Y10S 435/81 Packaged device or kit

Abstract

Analytical element method of making the analytical element and process for determining an analyte in a body fluid sample are disclosed. More particularly, the method of preparing the element comprises the steps of: (a) impregnating a carrier with a first solution, having a pH not greater than about 2.5, which comprises a polymeric mordant and a tetraalkylbenzidine dihydrochloride, in a molar concentration greater than that of the polymeric mordant in an aqueous solvent and drying the carrier; (b) impregnating the carrier of (a) with a solution, having a pH of at least about 7.0, which comprises an analyte-responsive component in an aqueous solvent and drying the carrier. Optionally, there can be added the step of impregnating the carrier of (b) with a solution of a semi-permeable polymer in an organic solvent and drying the carrier.

Claims

1. A method for preparing an analytical element for determining an analyte in a liquid sample which method comprises the steps of:

(a) impregnating a carrier with a first solution having a pH not greater than about 2.5, which comprises a polymeric mordant present in a concentration from about 0.5 to about 0.75 percent of the first solution on a weight to weight basis, and a tetraalkylbenzidine dihydrocholoride, with the tetraalkylbenzidine dihydrochloride in a molar concentration greater than that of the polymeric mordant, in an aqueous solvent and drying the carrier;

(b) impregnating the carrier of (a) with a second solution, having a pH of at least about 7.0, which comprises an enzyme and a peroxidatively active substance in an aqueous solvent and drying the carrier.

2. The method of claim 1 wherein the polymeric mordant is a methylvinyl ether maleic anhydride copolymer.

3. The method of claim 1 wherein the polymeric mordant is polyacrylic acid.

4. The method of claim 1 wherein the polymeric mordant is an acrylate-acrylamide copolymer.

5. The method of claim 1 wherein the polymeric mordant is a vinyl acetate-maleic anhydride copolymer.

6. The method of claim 1 wherein the tetraalkylbenzidine dihydrochloride is 3,3'"'"',5,5'"'"'-tetramethylbenzidine dihydrochloride.

7. The method of claim 1 wherein the tetraalkylbenzidine dihydrochloride is present in a concentration of from about 1.0 to about 2.0 percent of the first solution on a weight to weight basis.

8. The method of claim 1 wherein the enzyme and the peroxidatively active substance comprises an analyte-specific oxidase and a peroxidatively active substance.

9. The method of claim 1 wherein the enzyme and the peroxidatively active substance comprises glucose oxidase and peroxidase.

10. The method of claim 1 wherein the enzyme and the peroxidatively active substance comprises cholesterol oxidase and peroxidase.

11. The method of claim 1 wherein the enzyme and the peroxidatively active substance comprises cholesterol oxidase, cholesterol esterase and peroxidase.

12. The method of claim 1 wherein the enzyme and the peroxidatively active substance comprises uricase and peroxidase.

13. The method of claim 1 wherein the enzyme and the peroxidatively active substance comprises an amino acid oxidase and peroxidase.

14. The method of claim 1 wherein the enzyme and the peroxidatively active substance comprises xanthine oxidase and peroxidase.

15. The method of claim 1 which comprises the additional step of (c) impregnating the carrier of (b) with a solution of a semi-permeable polymer in an organic solvent and drying the carrier.

16. The method of claim 15 wherein the organic solvent includes toluene.

17. The method of claim 15 wherein the organic solvent includes toluene and ethanol.

18. The method of claim 15 wherein the organic solvent consists essentially of toluene, from about 80 to about 95 percent of the solvent, and ethanol, from about 5 to about 20 percent of the solvent, the toluene and ethanol being together 100 percent.

20. An analytical element for determining an analyte in a liquid sample, which element is prepared by the method of any of claims 1, 15 or 19.

21. A method for determining an analyte in a liquid sample which comprises contacting the sample with an analytical element prepared by the method of any of claims 1, 15 or 19 and observing any detectable response.

19. A method for preparing an analytical element for determining glucose in a liquid sample which method comprises the steps of:

(a) impregnating a carrier with a first solution, having a pH not greater than about 2.5, which comprises an interpolymer of methyl vinyl ether and maleic anhydride present in a concentration from about 0.5 to about 0.75 percent of the first solution on a weight to weight basis and 3,3'"'"',5,5'"'"'-tetramethylbenzidine dihydrochloride, in a molar concentration greater than that of the interpolymer, in an aqueous solvent and drying the carrier;

(b) impregnating the carrier of (a) with a solution, having a pH of at least about 7.0, which comprises glucose oxidase and peroxidase in an aqueous solvent and drying the carrier; and

(c) impregnating the carrier of (b) with a solution of ethyl cellulose in a solvent which consists essentially of toluene, from about 80 to about 95 percent of the solvent, and ethanol, from about 5 to about 20 percent of the solvent, the toluene and ethanol being together 100 percent, and drying the carrier.

22. A method for preparing an analytical element for determining cholesterol in a liquid sample which method comprises the steps of:

(a) impregnating a carrier with a first solution having a pH not greater than about 2.5, which comprises an interpolymer of methyl vinyl ether and maleic anhydride present in a concentration from about 0.5 to about 0.75% of the first solution on a weight to weight basis and 3,3'"'"',5,5'"'"'-tetramethylbenzidine dihydrocholoride, with the 3,3'"'"',5,5'"'"'-tetramethylbenzidine in a molar concentration greater than that of the interpolymer, in an aqueous solvent and drying the carrier;

(b) impregnating the carrier of (a) with a solution, having a pH of at least about 7.0, which comprises cholesterol oxidase, cholesterol esterase and peroxidase in an aqueous solvent and drying the carrier; and

(c) impregnating the carrier of (b) with a solution of ethyl cellulose and a solvent which consists essentially of toluene, from about 80 to about 95% of the solvent, and ethanol, from about 5 to about 20% of the solvent, the toluene and ethanol being together 100%, and drying the carrier.