Microfluidic ion-selective electrode sensor system

• US 7,101,472 B2
• Filed: 03/13/2003
• Issued: 09/05/2006
• Est. Priority Date: 03/13/2002
• Status: Active Grant

• Current Assignee: Charles Stark Draper Laboratory Incorporated
• Original Assignee: Charles Stark Draper Laboratory Incorporated
• Inventors: Williams, John R., Dineen, Andrew, Prince, Jennifer Ryan
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US10/388,202
• Publication Number:
  US 20030209451A1
• Time in Patent Office: 1,272 Days
• Field of Search: 204416-418, 204409-411, 204/412, 422/82.03, 205/792, 205/789, 205/789.5
• US Class Current: 205/792
• CPC Class Codes: G01N 27/333 Ion-selective electrodes or membranes glass electrodes G01N27/36
• CPC Class Codes: G01N 33/492 Determining multiple analytes

Abstract

Ion-selective electrode sensor systems, and methods of fabricating such systems, may be utilized to analyze microfluidic sample volumes, i.e., sample volumes on the order of 1 to 1000 microliters.

Claims

1. An ion-sensor system comprising:

a sampler assembly comprising;

an elongated tube having a proximal end and a distal end and defining a chamber, the proximal end dimensioned to draw a fluid into the chamber by capillary action; and

a connector portion; and

an ion-sensor cartridge comprising;

an electrical connection portion interconnecting with the sampler assembly connector portion; and

a plurality of ion-selective electrodes.

2. The ion-sensor system of claim 1, wherein the ion-sensor cartridge further comprises one or more reference electrodes.

3. The ion-sensor system of claim 1, wherein the proximal end comprises a lancet tip.

4. The ion-sensor system of claim 1, wherein the ion-sensor cartridge electrical connection portion is configured as one member of an edge-connector pair.

5. The ion-sensor system of claim 1, wherein the ion-sensor cartridge electrical connection portion is configured as one member of a pin-and-socket connector pair.

6. The ion-sensor system of claim 1, wherein at least one of the plurality of ion-selective electrodes detects at least one of the group consisting of sodium, chlorine, potassium, and calcium in the fluid.

7. The ion-sensor system of claim 1, wherein at least one of the plurality of ion-selective electrodes comprises an electrode layer and an ion-selective layer.

8. The ion-sensor system of claim 7, wherein the electrode layer comprises silver.

9. The ion-sensor system of claim 7, wherein the ion-selective layer comprises an ionophore.

10. The ion-sensor system of claim 9, wherein the ionophore comprises valinomycin.

11. The ion-sensor system of claim 9, wherein the ionophore comprises N,N,N′

,N′

-tetracyclohexyl-1,2-phenylenedioxydiacetamide.

12. The ion-sensor system of claim 9, further comprising an adhesion promoter anchoring the ionophore to a substrate or a dielectric layer disposed on a substrate.

13. The ion-sensor system of claim 12, wherein the adhesion promoter is glutyraldehyde.

14. A method of fabricating an ion-sensor system, the method comprising the steps of:

providing a substrate;

forming a plurality of ion-selective electrode regions on the substrate;

dividing the substrate into a plurality of strips such that each strip contains a plurality of ion-selective electrodes,

providing a sampler assembly comprising an elongated tube having a proximal end and a distal end and defining a chamber, the proximal end dimensioned to draw a fluid into the chamber by capillary action, and

disposing the strips within the chamber in electrical communication with the sampler assembly.

15. The method of claim 14, further comprising the step of forming one or more reference electrode regions on the substrate.

16. The method of claim 14, further comprising the step of forming an electrical connection portion on the substrate.

17. The method of claim 14, wherein at least one of the plurality of ion-selective electrodes detects at least one of the group consisting of sodium, chlorine, potassium, and calcium in the fluid.

18. The method of claim 14, wherein at least one of the plurality of ion-selective electrodes comprises an electrode layer and an ion-selective layer.

19. The method of claim 18, wherein the electrode layer comprises silver.

20. The method of claim 18, wherein the ion-selective layer comprises an ionophore.

21. The method of claim 14, further comprising applying an adhesion promoter to the substrate or a dielectric layer disposed on the substrate.

22. The method of claim 21, wherein the adhesion promoter is glutyraldehyde.

23. A method of measuring one or more electrolytes in blood, the method comprising the steps of:

extracting blood from a subject;

transferring the blood to an ion-sensor cartridge comprising an ion-selective electrode and disposed within a sampler assembly comprising an elongated tube having a proximal end and a distal end and defining a chamber, the proximal end dimensioned to draw the blood into the chamber by capillary action; and

analyzing one or more electrolytes in the blood.

24. The method of claim 23, wherein the extracting step comprises pricking a finger of the subject.

25. The method of claim 23, wherein the analyzing step comprises interfacing the ion-sensor cartridge with an electronic controller.