Composite membrane containing a cross-linked enzyme matrix for a biosensor

• US 6,960,466 B2
• Filed: 05/31/2001
• Issued: 11/01/2005
• Est. Priority Date: 05/31/2001
• Status: Active Grant

• Current Assignee: Instrumentation Lab Co (Instrumentation Lab)
• Original Assignee: Instrumentation Lab Co (Instrumentation Lab)
• Inventors: Shin, Melanie, Pamidi, Prasad, Mansouri, Sohrab, Cosofret, Vasile, Xu, Clarke
• Primary Examiner(s): Naff, David M.
• Application Number:
  US09/872,240
• Publication Number:
  US 20040211666A1
• Time in Patent Office: 1,615 Days
• Field of Search: 435/14, 435/25, 435/174, 435/177, 435/180, 435/817, 435/287.1, 435/182
• US Class Current: 435/287.1
• CPC Class Codes: C12Q 1/002 Electrode membranes
• CPC Class Codes: C12Q 1/003 Functionalisation
• CPC Class Codes: C12Q 1/005 involving specific analytes or enzymes including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence
• CPC Class Codes: C25D 9/02 with organic materials
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

An electrochemical sensor system and membrane and method thereof for increased accuracy and effective life of electrochemical and enzyme sensors.

Claims

1. A composite membrane for a biosensor, comprising:

an inner membrane layer comprising a restorable polymerizable membrane, the inner membrane layer adapted to function as an interference rejection membrane;

an outer membrane layer comprising polyurethane, and adapted to be disposed adjacent a flow channel during use; and

an enzyme layer disposed between and in contact with the inner and the outer membrane layers, said enzyme layer comprising a matrix comprising at least one enzyme, a cross-linking agent, and an enzyme stabilizer,

wherein the outer membrane is adapted to control diffusion of an analyte into the enzyme layer.

2. The composite membrane of claim 1, wherein said enzyme is lactate oxidase.

3. The composite membrane of claim 1, wherein said enzyme is creatinase.

4. The composite membrane of claim 1, wherein said enzyme is sarcosine oxidase.

5. The composite membrane of claim 1, wherein said enzyme is creatininase.

6. The composite membrane of claim 1, wherein said enzyme comprises a mixture of creatinase and sarcosine oxidase.

7. The composite membrane of claim 1, wherein said enzyme comprises a mixture of creatinase, creatininase and sarcosine oxidase.

8. The composite membrane of claim 1, wherein the inner membrane layer has a thickness less than about one micrometer.

9. The composite membrane of claim 1, wherein the inner membrane has pores sufficiently small to prevent passage of compounds in a sample liquid larger than hydrogen peroxide.

10. The composite membrane of claim 1, wherein the outer membrane layer has a thickness selected from a range of about 8 to 15 micrometers.