MEMBRANE FOR CHEMICAL AND BIOSENSORS

• US 20020025580A1
• Filed: 10/29/1998
• Published: 02/28/2002
• Est. Priority Date: 11/08/1995
• Status: Active Grant

• Current Assignee: Hypoguard USA Inc.
• Original Assignee: Hypoguard USA Inc.
• Inventors: KYROLAINEN, MARIKA S.K., VADGAMA, PANKAJ MAGANLAL, REDDY, SUBRAYAL MEDAPATI
• Granted Patent: US 6,706,532 B2
• Time in Patent Office: Days
• US Class Current: 436/149
• CPC Class Codes: C12Q 1/002 Electrode membranes

Abstract

Membranes incorporating surfactants of a synthetic polymer rendered permeable by the surfactant. The membranes are blood compatible and may be used in biosensors and also for dialysis. The preferred polymer is PVC.

Claims

1. A membrane permeable by mass transport to a species of interest and comprised of a synthetic polymeric material characterised in that the membrane further comprises a surface active agent which is miscible with the synthetic polymer, is distributed throughout the membrane and is present in an amount such as to provide for the permeability of the membrane.

2. A membrane as claimed in claim 1 wherein the synthetic polymeric material is poly(vinylchloride).

3. A membrane as claimed in claim 2 wherein the poly(vinylchloride) has a molecular weight (Mw) in the range 150,000 to 250,000.

4. A membrane as claimed in claim 3 wherein the poly(vinylchloride) has a molecular weight of about 200,000.

5. A membrane as claimed in any one of claims 1 to 4 having a thickness of 0.1 to 200 microns.

6. A membrane as claimed in any one of claims 1 to 5 wherein the surface active agent is a non-ionic surface active agent.

7. A membrane as claimed in any one of claims 1 to 5 wherein the surface active agent is comprised of or incorporates polyoxyalkylene residues.

8. A membrane as claimed in claim 7 wherein the alkylene oxide is ethylene oxide and/or propylene oxide.

9. A membrane as claimed in claim 8 wherein the surface active agent is a compound of the formula (I)

10. A membrane as claimed in claim 9 wherein the molecular weight of compound (I) is in the range 500 to 800.

11. A membrane as claimed in claim 10 wherein the molecular weight of compound (I) is in the range 600 to 700.

12. A membrane as claimed in any one of claims 1 to 5 wherein the surface active agent comprises a block copolymer of ethylene oxide and propylene oxide.

13. A membrane as claimed in claim 12 wherein the block copolymer has a molecular weight of 5,000 to 10,000.

14. A membrane as claimed in claim 13 wherein the block copolymer has a molecular weight of 7,000 to 10,000.

15. A membrane as claimed in any one of claims 1 to 5 wherein the surface active agent is L-α

-phosphatidyl choline dipalmitoyl.

16. A membrane as claimed in any one of claims 1 to 5 wherein the surface active agent is of the formula (II)

17. A membrane as claimed in any one of claims 1 to 16 wherein the amount of surface active agent is less than 50% (w/w) of the synthetic polymer.

18. A membrane as claimed in any one of claims 1 to 16 wherein the amount of surface active agent is at least 50% (w/w) of the synthetic polymer.

19. A membrane as claimed in any one of claims 12 to 14 which comprises 6% to 100% of the surface active agent based on the weight of the synthetic polymer.

20. A membrane as claimed in claim 19 which comprises 40% to 70% of the surface active agent based on the weight of the synthetic polymer.

21. A membrane as claimed in claim 18 wherein the amount of the surface active agent is 150% to 200% (w/w) of the synthetic polymer.

22. A membrane structure comprising a membrane as claimed in any one of claims 1 to 20 and a layer containing an immobilised enzyme.

23. A membrane structure as claimed in claim 22 wherein said layer comprises the enzyme cross-linked with bovine serum albumin in a glutararaldehyde matrix.

24. A membrane structure as claimed in claim 22 or 23 wherein the enzyme is an oxidase.

25. A membrane structure as claimed in claim 24 wherein the enzyme is lactate oxidase.

26. A membrane structure as claimed in claim 24 or 25 wherein the enzyme layer incorporates catalase.

27. A membrane structure as claimed in any one of claims 22 to 26 wherein said layer incorporating the enzyme is provided between said membrane and a further membrane for providing selectivity against interference.

28. A membrane structure as claimed in claim 27 wherein the selective membrane is comprised of a sulphonated poly(ether ether sulphone)/(poly (ether sulphone) polymer or cellulose acetate.

29. A sensor device comprising detecting means for detecting the amount of a species of interest in a sample and a membrane in accordance with any one of claims 1 to 20 providing both a barrier function and a biocompatible interface function between the detecting means and the sample.

30. A sensor device as claimed in claim 29 wherein the detecting system comprises an electrochemical electrode system.

31. A sensor device as claimed in claim 30 wherein the electrochemical electrode system is of the non-potentiometric type.

32. A sensor device as claimed in claim 31 wherein the electrochemical electrode system comprises an amperometric electrode.

33. A sensor device as claimed in any one of claims 29 to 32 which is a biosensor.

34. A sensor device as claimed in any one of claims 29 to 32 which is a biosensor and which is provided with an enzyme on the electrode side of the membrane.

35. A sensor device as claimed in claim 34 wherein the enzyme is immobilised in a layer provided between the membrane and the electrode.

36. A sensor device as claimed in claim 35 wherein said layer comprises the enzyme cross-linked with bovine serum albumin in a glutararaldehyde matrix.

37. A sensor device as claimed in any one of claims 34 to 36 wherein the enzyme is lactate oxidase.

38. A sensor device as claimed in any one of claims 34 to 37 incorporating a further membrane between the enzyme and the electrode to provide selectivity against interferents.

39. A sensor device as claimed in claim 38 wherein the selective membrane is comprised of a sulphonated poly(ether ether sulphone)/(poly (ether sulphone) polymer or cellulose acetate.

40. A method of determining the amount of a selected component in a sample, the method comprising using a sensor device which incorporates means for detecting the amount of the component in a sample and either a membrane as claimed in any one of claims 1 to 20 or a membrane structure as claimed in any one of claims 22 to 28, said membrane or membrane structure being located in contact with the sample and providing both a barrier function and a biocompatible interface function between the sample and the detection means.

41. A method as claimed in claim 40 wherein the sample is whole blood and the selected component is lactate.

42. A method as claimed in claim 38 or 39 which is effected under continuous flow conditions.