Microfluidic test device

• US 20050230252A1
• Filed: 02/22/2005
• Published: 10/20/2005
• Est. Priority Date: 02/23/2004
• Status: Active Grant

• Current Assignee: Leadway (Hk) Limited (Akatsuki Corp.)
• Original Assignee: Leadway (Hk) Limited (Akatsuki Corp.)
• Inventors: Lin, Jinn-nan, Tsai, Fu Hsiung, Wang, Chia-Lin
• Granted Patent: US 7,807,043 B2
• Time in Patent Office: Days
• US Class Current: 204/450
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: G01N 33/5438 Electrodes

Abstract

The present invention provides biosensor test devices for measuring the presence or amount of an analyte in a biological fluid. The devices have a base plate that has an electrode system embedded therein, and a hydrophilic porous material situated on the base plate. A hydrophobic protective layer is situated on the hydrophilic porous material, and a cover is placed on the hydrophobic protective layer to complete the device. Some embodiments also use an insulating layer, which can be situated between the base layer and the hydrophilic porous material. The cover of the device has an opening present therein, situated over the electrodes, so that the electrodes communicate with the exterior of the device through the groove. The insulating layer can also have a groove situated therein, which in one embodiment is placed to align with the groove in the cover. The invention also provides methods of manufacturing the devices, and methods of using them.

Claims

1. A microfluidic device for determining the amount of an analyte in a sample, comprising:

a base plate comprising an electrode system having at least two electrodes in a dielectric material;

a reaction layer on at least one of the electrodes comprising reagents for producing a detectable signal in response to a quantity of analyte in the sample;

a hydrophilic porous material for holding a liquid sample in contact with the base plate;

a hydrophobic protective layer disposed on the hydrophilic porous material;

a cover made of a dielectric material and having a proximal end and a distal end comprised on the hydrophobic protective layer and containing an opening providing for communication between the electrodes and the exterior of the device.

2. The device of claim 1 further comprising an insulating layer disposed between the base plate and the hydrophilic porous material and comprising a groove, and being comprised of a hydrophobic, dielectric material;

and

wherein the hydrophilic porous material is disposed between the insulating layer and the hydrophobic protective layer.

3. The device of claim 1 wherein the at least two electrodes comprise a working electrode, a reference electrode, and a counter electrode.

4. The device of claim 1 wherein the base plate is made of a material selected from the group consisting of:

carbon, polystyrene, polycarbonate, and a polyester.

5. The device of claim 1 wherein the hydrophilic porous material is selected from the group consisting of:

a gel, glass fiber, a porous plastic, polyester, a mesh, a cellulose material, and a polyester.

7. The device of claim 1 wherein the protective layer is comprised of a material selected from the group consisting of:

a gel, glass fiber, porous plastics, cellulose material, a polyester, a mesh, a gel, a glass fiber, a porous plastic, and a cellulose material.

8. The device of claim 7 wherein the protective layer is present in the form of a mesh.

9. The device of claim 1 wherein the cover is comprised of a hydrophobic, non-conductive material selected from the group consisting of:

an ink, adhesive, adhesive tape, a plastic, a celluloid material, glass, and a non-conductive foil; and

wherein the opening in the cover comprises a groove extending from the proximal to the distal end of the cover.

10. The device of claim 2 wherein the cover and insulating layer are comprised of a non-conductive material selected from the group consisting of:

an ink, adhesive, adhesive tape, a plastic, a celluloid material, glass, and a non-conductive foil; and

wherein the opening in the cover comprises a second groove extending from the proximal to the distal end of the device and is aligned with the groove of the insulating layer.

11. The device of claim 1 wherein the hydrophilic porous material and the protective layer cover at least the proximal portion of the base plate, and the at least two electrodes communicate with the exterior of the device through the groove formed by the proximal end of the cover.

12. The device of claim 1 wherein the protective layer is situated between the hydrophilic porous material and the cover, and extends across the opening in the cover.

13. The device of claim 1 wherein the reaction layer comprises glucose oxidase.

14. The device of claim 3 wherein the counter electrode is closest to the proximal end of the base plate, and the reference electrode is farthest from the proximal end of the base plate.

15. The device of claim 1 wherein the hydrophilic porous material is disposed on the base plate, the hydrophobic protective layer is disposed on the hydrophilic porous material, and the cover is disposed on at least the hydrophobic protective layer.

16. The device of claim 2 wherein the base plate, groove, and hydrophilic porous material define a reaction chamber, and the reaction layer is comprised within the reaction chamber.

19. The method of claim 1 wherein the insulation layer is placed by a method selected from the group consisting of:

screen printing, ink jet printing, application of adhesive or adhesive tape, lamination of the layers of material, heat sealing, and ultrasonic welding.

6. The device of claim 6 wherein the hydrophilic porous material is a mesh.

17. A method of manufacturing a microfluidic device, comprising:

placing a reagent formulation for conducting an assay onto at least one electrode of a base plate comprising an electrode system having at least two electrodes in a dielectric material;

applying a hydrophilic porous material to the base plate;

affixing a hydrophobic protective layer to the hydrophilic porous material;

affixing a cover made of a dielectric material and having a proximal end and a distal end to the hydrophobic protective layer, wherein the cover contains an opening providing communication between the electrodes and the exterior of the device.

18. The method of claim 17 further comprising placing an insulating layer on the base plate before applying the hydrophilic porous material, wherein the insulating layer has a groove, and the insulating layer is comprised of a hydrophobic, dielectric material.

20. The method of claim 17 wherein the at least two electrodes are three electrodes comprising a working electrode, a reference electrode, and a counter electrode.

21. The method of claim 17 wherein the base plate is made of a material selected from the group consisting of:

carbon, polystyrene, polycarbonate, and a polyester.

22. The method of claim 17 wherein the hydrophilic porous material is selected from the group consisting of:

a gel, glass fiber, a porous plastic, cellulose, a mesh, a gel, a glass fiber, a porous plastic, a cellulose material, and a polyester.

23. The method of claim 17 wherein the hydrophobic protective layer is comprised of a material selected from the group consisting of:

a gel, glass fiber, porous plastics, cellulose material, and polyester, a hydrophobic mesh, a hydrophobic gel, a hydrophobic glass fiber, a hydrophobic porous plastic, a cellulose material, or hydrophobic polyester, and

the hydrophobic protective is situated between the hydrophilic porous material and the cover; and

the opening in the proximal end of the cover is a groove, and the hydrophobic protective layer extends across the groove.

24. The method of claim 17 wherein the cover is comprised of a hydrophobic non-conductive material selected from the group consisting of:

an ink, adhesive, adhesive tape, a plastic, a celluloid material, glass, and a non-conductive foil.

25. The method of claim 17 wherein the hydrophilic porous material and the hydrophobic protective layer are placed to cover at least the proximal portion of the base plate, and the at least two electrodes communicate with the exterior of the device through the opening in the proximal end of the cover.

26. The method of claim 17 wherein the hydrophilic porous material is placed on the base plate by a method selected from the group consisting of:

screen printing, ink jet printing, application of adhesive or adhesive tape, lamination of the layers of material, heat sealing, and ultrasonic welding.

27. The method of claim 17 wherein the hydrophobic protective layer is placed on the hydrophilic porous material by a method selected from the group consisting of:

screen printing, ink jet printing, application of adhesive or adhesive tape, lamination of the layers of material, heat sealing, and ultrasonic welding.

28. The method of claim 17 wherein the hydrophobic protective layer and/or cover are placed by a method selected from the group consisting of:

screen printing, ink jet printing, application of adhesive or adhesive tape, lamination of the layers of material, heat sealing, and ultrasonic welding.

29. A method of determining the concentration of an analyte in a fluid sample comprising:

placing a portion of the sample on a test device comprising;

a base plate comprising an electrode system having at least two electrodes in a dielectric material;

a reaction layer on at least one of the electrodes comprising materials for producing a detectable signal in response to a quantity of analyte in the sample;

a hydrophilic porous material for wicking a liquid sample into contact with the first layer;

a hydrophobic protective layer comprised on the wicking material; and

a cover made of a hydrophobic, dielectric material and having a proximal and a distal end comprised on the hydrophobic protective and containing an opening providing for communication between the electrodes and the exterior of the device;

inserting the test device into an electronic detection system so that the test device is connected to the detection system through the contact leads of the test device;

determining the concentration of the analyte in the fluid sample.

30. The method of claim 29 wherein:

the device further comprises an insulating layer disposed between the base plate and the hydrophilic porous material, and insulating layer comprised of a hydrophobic, dielectric material, and comprising a groove in alignment with the opening in the cover.

31. The method of claim 29 wherein

the at least two electrodes are three electrodes comprising a working electrode, a reference electrode, and a counter electrode;

the base plate is made of a material selected from the group consisting of;

carbon, polystyrene, polycarbonate, and a polyester;

the hydrophilic porous material is a material selected from the group consisting of;

a gel, glass fiber, a porous plastic, a cellulosic material, and a polyester;

the hydrophobic protective layer is comprised of a material selected from the group consisting of;

a gel, glass fiber, a porous plastic, a cellulosic material, and a polyester; and

the cover and insulating layer are comprised of a non-conductive material selected from the group consisting of;

an ink, adhesive, adhesive tape, a plastic, a celluloid material, glass, and a non-conductive foil.