Disposable urea sensor and system for determining creatinine and urea nitrogen-to-creatinine ratio in a single device

• US 8,617,366 B2
• Filed: 12/12/2005
• Issued: 12/31/2013
• Est. Priority Date: 12/12/2005
• Status: Active Grant

• Current Assignee: Nova Biomedical Corporation (Nova Chemicals)
• Original Assignee: Nova Biomedical Corporation (Nova Chemicals)
• Inventors: Winarta, Handani, Pei, Jianhong, Lauro, Mary, Young, Chung Chang, Cai, Xiaohua
• Primary Examiner(s): DINH, BACH T
• Application Number:
  US11/164,935
• Publication Number:
  US 20070131548A1
• Time in Patent Office: 2,941 Days
• Field of Search: 20440301-40315, 2057775-781
• US Class Current: 204/403.01
• 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: G01N 27/3271 Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood amperometry per se G01N27/49; aspects concerning the enzyme reagent C12Q1/001

Abstract

A disposable urea sensor has a laminated body having a fluid sample inlet end and an electrical contact end, a fluid sample inlet, a substantially flat sample chamber in communication between the fluid sample inlet and a vent opening, the sample chamber being adapted to collect a fluid sample through the fluid sample inlet, a working electrode and a reference electrode within the sample chamber, and a reagent matrix disposed on the working electrode wherein the reagent matrix contains urease.

Claims

1. A disposable urea sensor comprising:

a laminated body having a fluid sample inlet end and an electrical contact end, said laminated body includes a base layer, a reagent holding layer with cutouts defining a working electrode and a reference electrode, a channel forming layer and a cover;

a fluid sample inlet at said fluid sample inlet end;

a substantially flat sample chamber in communication between said fluid sample inlet and a vent opening wherein said sample chamber is adapted to collect a fluid sample through said fluid sample inlet, said substantially flat sample chamber defined by said base layer, said reagent holding layer, said channel forming layer and said cover;

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

a dissolvable mixture of a reagent matrix disposed directly on said working electrode wherein said reagent matrix contains urease but absent any redox mediator and a dissolvable mixture of a reference matrix disposed directly on said reference electrode wherein said reference matrix contains a redox mediator.

2. The sensor of claim 1 wherein said reagent matrix further includes one or more of the materials selected from the group consisting of a binder, a buffer, a surfactant, a stabilizer, and a bulking agent.

3. The sensor of claim 2 wherein said binder is a cellulose material.

4. The sensor of claim 3 wherein said cellulose material is hydroxypropyl cellulose.

5. The sensor of claim 1 further comprising a blank electrode and a second reagent matrix disposed on said blank electrode wherein said second reagent matrix includes a buffer.