Amperometric Creatinine Biosensor With Immobilized Enzyme-Polymer Composition And Systems Using Same, And Methods

• US 20120181189A1
• Filed: 08/18/2010
• Published: 07/19/2012
• Est. Priority Date: 09/24/2009
• Status: Abandoned Application

• Current Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Original Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Inventors: Merchant, Stephen A.
• Application Number:
  US13/497,083
• Publication Number:
  US 20120181189A1
• Time in Patent Office: Days
• US Class Current: 205/777.5
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: G01N 2333/906 acting on nitrogen containing compounds as donors (1.4, 1.5, 1.7)

Abstract

An amperometric biosensor is provided for determination of creatinine in a sample fluid. The biosensor can be an enzyme-polymer composition having at least one redox polymer and a plurality of enzymes immobilized on an electrode surface. Methods of preparing the amperometric biosensor are included. In addition, methods and systems using the amperometric biosensor in measuring creatinine concentrations of a patient and treatments of a patient with monitoring of the progress of dialysis performed on the patient are also provided.

Claims

1. An amperometric biosensor for determination of creatinine in a sample fluid comprising an enzyme-polymer composition and an electrode having a surface, wherein the enzyme-polymer composition comprises at least one redox polymer and a plurality of enzymes immobilized on the electrode surface, and wherein the enzymes comprise at least one redox enzyme and at least one enzyme catalyzing hydrolysis of creatinine or a hydrolyzed derivative thereof.

2. The biosensor of claim 1, wherein the enzyme-polymer composition is a coating on the surface of the electrode.

3. The biosensor of claim 1, where the redox polymer is attached to the enzymes and the electrode surface of the biosensor through crosslinking.

4. The biosensor of claim 1, wherein the redox polymer comprises a neutral polymeric backbone and redox active moieties attached thereto.

5. The biosensor of claim 1, wherein the redox polymer comprises a neutral polymeric backbone and redox active moieties attached thereto, wherein the redox moieties comprise organometallic species comprising a transition metal.

6. The biosensor of claim 1, wherein said redox polymer is X-poly(vinylpyridine), X-poly(vinylimidazole), X-poly(allylamine), or X-poly(ethyleninime) or any combination thereof, where X is at least one organometallic moiety comprising a transition metal that is iron, osmium, ruthenium, or cobalt or any combination thereof.

7. The biosensor of claim 1, wherein said plurality of immobilized enzymes comprise creatinine amidohydrolase, creatine amidinohydrolase, and sarcosine oxidase.

8. The biosensor of claim 1, wherein said composition contains from about 1 wt % to about 99 wt % redox polymer, from about 1 wt % to about 99 wt % enzymes, and from about 1 wt % to about 30 wt % crosslinker, wherein the enzymes comprise creatinine amidohydrolase, creatine amidinohydrolase, and sarcosine oxidase.

9. The biosensor of claim 1, wherein said biosensor comprises at least one working electrode, at least one reference electrode and at least one counter electrode.

10. The biosensor of claim 1, wherein said biosensor comprises at least one working electrode, at least one reference electrode and at least one counter electrode, and wherein the enzyme-polymer composition is applied to said working electrode.

11. A dialysis system comprising the amperometric biosensor of claim 1.

13. A method for making the amperometric biosensor of claim 1 comprising:

depositing an aqueous mixture containing said plurality of enzymes, at least one redox polymer and at least one crosslinker on a surface of said electrode; and

crosslinking the mixture to form said enzyme-polymer composition immobilized on the electrode surface.

14. The method of claim 13, wherein said plurality of enzymes comprise creatinine amidohydrolase, creatine amidinohydrolase, and sarcosine oxidase.

15. The method of claim 13, wherein said redox polymer is X-poly(vinylpyridine), X-poly(vinylimidazole), X-poly(allylamine), or X-poly(ethyleninime) or any combination thereof, where X is at least one organometallic moiety comprising a transition metal that is iron, osmium, ruthenium, or cobalt, or any combination thereof.

16. A method of detecting creatinine concentration in a sample fluid, comprising:

contacting the biosensor of claim 1 with a sample fluid;

measuring current at the electrode; and

correlating the measured current with creatinine concentration in the sample fluid.

17. The method of claim 16, wherein the sample fluid is a dialysate stream.

18. The method of claim 16, wherein the sample fluid is a biological fluid.

19. The method of claim 16, wherein the electrode is operated at from about 350 to about 400 mV.

20. A method of treating an animal for clearance of creatinine, comprising:

contacting the biosensor of claim 1 with a fluid stream of a dialyzer used in the dialysis of an animal; and

measuring creatinine concentration in said fluid stream of the dialyzer with the biosensor.

21. The method of claim 20, wherein the fluid stream used for the creatinine concentration measurement is a dialysate stream.

22. The method of claim 20, wherein the fluid stream used for the creatinine concentration measurement is a post-dialyzer dialysate stream.

23. The method of claim 20, where the creatinine concentration measurement is done in real time continuously, semi-continuously, or intermittently.

24. The method of claim 20, further comprising discontinuing dialysis treatment on the animal after a measured creatinine concentration reaches a pre-selected target value.

12. An immobilized enzyme-polymer composition for an electrode surface comprising at least one crosslinked redox polymer and a plurality of enzymes comprising at least one redox enzyme and at least one enzyme catalyzing hydrolysis of creatinine or a hydrolyzed derivative thereof.