Oxygen Sensor

• US 20070023296A1
• Filed: 07/26/2005
• Published: 02/01/2007
• Est. Priority Date: 07/26/2005
• Status: Active Grant

• Current Assignee: Nova Biomedical Corporation (Nova Chemicals)
• Original Assignee: Nova Biomedical Corporation (Nova Chemicals)
• Inventors: Cai, Xiaohua, Alesi, Kara, Young, Chung
• Granted Patent: US 7,648,624 B2
• Time in Patent Office: Days
• US Class Current: 205/782
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52

Abstract

An oxygen sensor has a laminated body with a fluid sample inlet end and an electrical contact end, a fluid sample inlet, a substantially flat test chamber communicating with the fluid sample inlet where the test chamber is adapted to collect a fluid sample through the sample fluid inlet, a working electrode and a reference electrode within the test chamber, and a reagent matrix disposed on the working electrode where the reagent matrix contains an oxidase, a reduced form of a redox mediator and a peroxidase.

Claims

1. An oxygen sensor comprising:

a laminated body having a fluid sample inlet end and an electrical contact end;

a fluid sample inlet;

a substantially flat test chamber communicating with said fluid sample inlet, said test chamber being adapted to collect a fluid sample through said fluid sample inlet;

a working electrode and a reference electrode within said test chamber; and

a reagent matrix disposed on said working electrode wherein said reagent matrix contains an oxidase, a reduced form of a redox mediator and a peroxidase.

2. The oxygen sensor of claim 1 wherein said laminated body includes a bottom layer, a channel forming layer and a cover wherein said bottom layer, said channel forming layer and said cover define said substantially flat test chamber.

3. The oxygen sensor of claim 2 wherein said laminated body further includes a reagent holding layer between said bottom layer and said channel forming layer.

4. The oxygen sensor of claim 3 wherein said reagent holding layer has a first opening forming a working electrode well and a second opening forming a reference electrode well.

5. The oxygen sensor of claim 1 wherein said oxidase is capable of producing hydrogen peroxide.

6. The oxygen sensor of claim 5 wherein said oxidase is selected from the group consisting of glucose oxidase, acyl-CoA oxidase, N-acylhexosamine oxidase, D-amino acid oxidase, cholesterol oxidase, fructosyl-peptide oxidase, glutamate oxidase, L-α

-glycerophosphate oxidase, lactate oxidase, putrescine oxidase, pyranose oxidase, pyruvate oxidase, sarcosine oxidase, uricase, and xanthine oxidase.

7. The oxygen sensor of claim 1 wherein said reduced form of said redox mediator is capable of being oxidized by hydrogen peroxide.

8. The oxygen sensor of claim 7 wherein said reduced form of said redox mediator is selected from the group consisting of potassium ferrocyanide, [Fe(phen)₃]²⁺, [Fe(bpy)₃]²⁺, [Co(NH₃)]²⁺, [Co(phen)₃]²⁺, [Co(bpy)₃]²⁺, [Os(bpy)₂Cl]⁺, [Os(phen)₂Cl]⁺, [Ru(bpy)₂]²⁺, [Rh(bpy)₂]²⁺, cobalt phthalocyanine, ferrocenes, methylene blue, methylene green, 7,7,8,8-tetracyanoquinodimethane, tetrathiafulvalene, toluidine blue, meldola blue, N-methylphenazine methosulfate, phenyldiamines, 3,3′

,5,5′

-tetramethylbenzidine, pyrogallol, and benzoquinone wherein phen is 1,10-phenanthroline and bpy is 2,2′

-bipyridine.

9. The oxygen sensor of claim 1 wherein said peroxidase is selected from the group consisting of soybean peroxidase and horseradish root peroxidase.

10. The oxygen sensor of claim 1 wherein said reagent matrix further includes one or more of a material selected from the group consisting of a surfactant, a polymer binder, an inactive bulking agent, and an antioxidant.

11. The oxygen sensor of claim 10 wherein said surfactant is selected from the group consisting of anionic, cationic, non-ionic, and zwitterionic detergents.

12. The oxygen sensor of claim 11 wherein said surfactant is selected from the group consisting of Triton X-100, Tween 20, sodium cholate hydrate, hexadecylpyridinium cholide monohydrate, and CHAPs.

13. The oxygen sensor of claim 10 wherein said inactive bulking agent is a sugar.

14. The oxygen sensor of claim 13 wherein said sugar is selected from the group consisting of trehalose, galactose, suctose, lactose, mannitol, mannose, fructose, sucrose, lactose, lactitol, sorbitol, xylitol, and maltose.

15. The oxygen sensor of claim 10 wherein said antioxidant is selected from the group consisting of reductants and oxygen scavengers.

16. The oxygen sensor of claim 15 wherein said antioxidant is selected from the group consisting of sodium sulfite, sodium hydrosulfite, hydrazine, hydroquinone, carbohydrazide, N,N-Diethylhydroxylamine, methylethylketoxime, diethylthreitol, erythorbic acid, and ascorbic acid.

17. The oxygen sensor of claim 10 wherein said polymer binder is selected from the group consisting of polyvinylpyrrolidone, polyethylene oxide, poly(vinyl alcohol), poly(ethylene glycol), poly(propylene glycol), polysulfone, carboxy methyl cellulose, hydroxypropyl cellulose, methyl cellulose, poly(2-ethyl-2oxazoline).

18. The oxygen sensor of claim 10 wherein said polymer binder is a mixture of polyethylene oxide and methyl cellulose.

19. A system for determining the oxygen concentration in a fluid sample, said system comprising:

an oxygen sensor comprising a working electrode, a reference electrode and a reagent matrix disposed on at least said working electrode wherein said reagent matrix contains a reduced form of a redox mediator, an oxidase and a peroxidase;

means for determining an analyte concentration in said fluid sample wherein said analyte is a substrate of said oxidase; and

means for determining an oxygen concentration in said fluid sample using said oxygen sensor.

20. The system of claim 19 wherein said oxidase is capable of producing hydrogen peroxide.

21. The system of claim 20 wherein said oxidase is selected from the group consisting of glucose oxidase, acyl-CoA oxidase, N-acylhexosamine oxidase, D-amino acid oxidase, cholesterol oxidase, fructosyl-peptide oxidase, glutamate oxidase, L-α

-glycerophosphate oxidase, lactate oxidase, putrescine oxidase, pyranose oxidase, pyruvate oxidase, sarcosine oxidase, uricase, and xanthine oxidase.

22. The system of claim 19 wherein said reduced form of said redox mediator is capable of being oxidized by hydrogen peroxide.

23. The system of claim 22 wherein said reduced form of said redox mediator is selected from the group consisting of potassium ferrocyanide, [Fe(phen)₃]²⁺, [Fe(bpy)₃]²⁺, [Co(NH₃)]²⁺, [Co(phen)₃]²⁺, [Co(bpy)₃]²⁺, [Os(bpy)₂Cl]⁺, [Os(phen)₂Cl]⁺, [Ru(bpy)₂]²⁺, [Rh(bpy)₂]²⁺, cobalt phthalocyanine, ferrocenes, methylene blue, methylene green, 7,7,8,8-tetracyanoquinodimethane, tetrathiafulvalene, toluidine blue, meldola blue, N-methylphenazine methosulfate, phenyldiamines, 3,3′

,5,5′

-tetramethylbenzidine, pyrogallol, and benzoquinone wherein phen is 1,10-phenanthroline and bpy is 2,2′

-bipyridine.

24. The system of claim 19 wherein said peroxidase is selected from the group consisting of soybean peroxidase and horseradish root peroxidase.

25. The system of claim 19 wherein said reagent matrix further includes one or more of a material selected from the group consisting of a surfactant, a polymer binder, an inactive bulking agent, and an antioxidant.

26. The system of claim 25 wherein said surfactant is selected from the group consisting of anionic, cationic, non-ionic, and zwitterionic detergents.

27. The system of claim 26 wherein said surfactant is selected from the group consisting of Triton X-100, Tween 20, sodium cholate hydrate, hexadecylpyridinium cholide monohydrate, and CHAPs.

28. The system of claim 25 wherein said inactive bulking agent is a sugar.

29. The system of claim 28 wherein said sugar is selected from the group consisting of trehalose, galactose, suctose, lactose, mannitol, mannose, fructose, sucrose, lactose, lactitol, sorbitol, xylitol, and maltose.

30. The system of claim 25 wherein said antioxidant is selected from the group consisting of reductants and oxygen scavengers.

31. The system of claim 30 wherein said antioxidant is selected from the group consisting of sodium sulfite, sodium hydrosulfite, hydrazine, hydroquinone, carbohydrazide, N,N-Diethylhydroxylamine, methylethylketoxime, diethylthreitol, erythorbic acid, and ascorbic acid.

32. The system of claim 25 wherein said polymer binder is selected from the group consisting of polyvinylpyrrolidone, polyethylene oxide, poly(vinyl alcohol), poly(ethylene glycol), poly(propylene glycol), polysulfone, carboxy methyl cellulose, hydroxypropyl cellulose, methyl cellulose, and poly(2-ethyl-2oxazoline).

33. The system of claim 25 wherein said polymer binder is a mixture of polyethylene oxide and methyl cellulose.

34. The system of claim 19 wherein said means for determining said oxygen concentration includes an oxygen empirical equation based on empirical data obtained with the configuration of said oxygen sensor.

35. The system of claim 34 wherein said oxygen empirical equation is represented by the formula pO₂=ai²+bi+k₁ where a and b are empirical constants at a given glucose concentration in milligrams per deciliter determined by the configuration of said oxygen sensor, K₁ is an empirical constant based on electrode configuration, and i is the current in nanoamps measured by said oxygen sensor.

36. A method of determining the concentration of oxygen in a biological sample, said method comprising:

using an oxygen sensor comprising a working electrode, a reference electrode and a reagent matrix disposed on at least said working electrode wherein said reagent matrix contains a reduced form of a redox mediator, an oxidase and a peroxidase;

determining an analyte concentration of said biological sample wherein said analyte concentration is a substrate of said oxidase; and

determining said concentration of oxygen in said biological sample using said determined analyte concentration.

37. The method of claim 36 wherein said oxygen concentration using step further includes determining an oxygen empirical equation based on empirical data obtained with said oxygen sensor.

38. The method of claim 37 wherein said oxygen empirical equation is represented by the formula pO₂=ai²+bi+k₁ where a and b are empirical constants at a given glucose concentration in milligrams per deciliter determined by the configuration of said oxygen sensor, K₁ is an empirical constant based on electrode configuration, and i is the current in nanoamps measured by said oxygen sensor.

39. The method of claim 36 further comprising fabricating said oxygen sensor by laminating a bottom layer, a channel forming layer and a cover forming a laminated body having a fluid sample inlet on one end, a substantially flat sample chamber in communication with said fluid sample inlet, said test chamber being adapted to collect a fluid sample through said fluid sample inlet, and electrical contacts on the other end wherein said working electrode and said reference electrode are within said sample chamber.

40. The method of claim 39 further comprising laminating a reagent holding layer between said bottom layer and said channel forming layer.

41. The method of claim 36 further comprising fabricating said reagent matrix by selecting said reduced form of said redox mediator from redox mediators capable of being oxidized by hydrogen peroxide.

42. The method of claim 41 further comprising fabricating said reagent matrix by selecting said reduced form of said redox mediator from the group consisting of potassium ferrocyanide, [Fe(phen)₃]²⁺, [Fe(bpy)₃]²⁺, [Co(NH₃)]²⁺, [Co(phen)₃]²⁺, [Co(bpy)₃]²⁺, [Os(bpy)₂Cl]⁺, [Os(phen)₂Cl]⁺, [Ru(bpy)₂]²⁺, [Rh(bpy)₂]²⁺, cobalt phthalocyanine, ferrocenes, methylene blue, methylene green, 7,7,8,8-tetracyanoquinodimethane, tetrathiafulvalene, toluidine blue, meldola blue, N-methylphenazine methosulfate, phenyldiamines, 3,3′

,5,5′

-tetramethylbenzidine, pyrogallol, and benzoquinone wherein phen is 1,10-phenanthroline and bpy is 2,2′

-bipyridine.

43. The method of claim 36 further comprising fabricating said reagent matrix by selecting said oxidase from oxidases capable of producing hydrogen peroxide.

44. The method of claim 43 further comprising fabricating said reagent matrix by selecting said oxidase from the group consisting of glucose oxidase, acyl-CoA oxidase, N-acylhexosamine oxidase, D-amino acid oxidase, cholesterol oxidase, fructosyl-peptide oxidase, glutamate oxidase, L-α

-glycerophosphate oxidase, lactate oxidase, putrescine oxidase, pyranose oxidase, pyruvate oxidase, sarcosine oxidase, uricase, and xanthine oxidase.

45. The method of claim 36 further comprising fabricating said reagent matrix by selecting said peroxidase from the group consisting of soybean peroxidase and horseradish root peroxidase.

46. The method of claim 36 further comprising fabricating said reagent matrix by including one or more of the materials selected from the group consisting of a surfactant, a polymer binder, an inactive bulking agent, and an antioxidant.

47. The method of claim 46 further includes selecting said surfactant from the group consisting of anionic, cationic, non-ionic, and zwitterionic detergents.

48. The method of claim 46 further includes selecting said surfactant from the group consisting of Triton X-100, Tween 20, sodium cholate hydrate, hexadecylpyridinium cholide monohydrate, and CHAPs.

49. The method of claim 46 further includes selecting said polymer binder from the group consisting of polyvinylpyrrolidone, polyethylene oxide, poly(vinyl alcohol), poly(ethylene glycol), poly(propylene glycol), polysulfone, carboxy methyl cellulose, hydroxypropyl cellulose, methyl cellulose, and poly(2-ethyl-2oxazoline).

50. The method of claim 46 further includes selecting said polymer binder to be a mixture of polyethylene oxide and methyl cellulose.

51. The method of claim 46 further includes selecting said inactive bulking agent from the group consisting of trehalose, galactose, suctose, lactose, mannitol, mannose, fructose, sucrose, lactose, lactitol, sorbitol, xylitol, and maltose.

52. The method of claim 46 further includes selecting said antioxidant from the group consisting of reductants and oxygen scavengers.

53. The method of claim 46 further includes selecting said antioxidant from the group consisting of sodium sulfite, sodium hydrosulfite, hydrazine, hydroquinone, carbohydrazide, N,N-Diethylhydroxylamine, methylethylketoxime, diethylthreitol, erythorbic acid, and ascorbic acid.