Strip electrode with conductive nano tube printing

• US 7,285,198 B2
• Filed: 02/23/2005
• Issued: 10/23/2007
• Est. Priority Date: 02/23/2004
• Status: Expired due to Fees

• Current Assignee: Joel S. Douglas
• Original Assignee: MysticMD Inc. (eGen Partners LLC)
• Inventors: Douglas, Joel S.
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US11/063,504
• Publication Number:
  US 20050186333A1
• Time in Patent Office: 972 Days
• Field of Search: 204/400, 20440301-40315, 205/775, 205/777.5, 205/778, 205/792
• US Class Current: 204/403.14
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C12Q 1/002 Electrode membranes
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

An electrochemical test device for determining the presence or concentration of an analyte in an aqueous fluid sample comprises a substrate comprising a non-conductive material; a working electrode comprising a conductive film formed at least with carbon nanotubes, the working electrode having a first electrode area, a first lead and a first contact pad; a counter electrode comprising a conductive film formed at least with carbon nanotubes; a reagent capable of reacting with the analyte to produce a measurable change in potential which can be correlated to the presence or concentration of the analyte in the fluid sample, the reagent overlaying at least a portion of the first electrode area of the working electrode; and a reference electrode comprising a conductive coating formed at least with carbon nanotubes, the reference electrode having a third electrode area at least a portion of which is overlaid with a reference material.

Claims

1. An electrochemical test device for determining the presence or concentration of an analyte in an aqueous fluid sample, said electrochemical test device comprising:

(a) a substrate, the substrate comprising a non-conductive material;

(b) a working electrode comprising a conductive film formed with carbon nanotubes and other conductive and non conductive materials affixed to the non-conductive substrate, said working electrode having a first electrode area, a first lead and a first contact pad;

(c) a counter electrode comprising a conductive film formed with carbon nanotubes and other conductive and non conductive materials affixed to the non-conductive substrate, said counter electrode having a second electrode area, a second lead and a second contact pad;

(d) a reagent capable of reacting with the analyte to produce a measurable change in potential which can be correlated to the presence or concentration of the analyte in the fluid sample, said reagent overlaying at least a portion of the first electrode area of the working electrode; and

(e) a reference electrode comprising a conductive coating formed with carbon nanotubes and other conductive and non conductive materials affixed to the non-conductive substrate, said reference electrode having a third electrode area, a third lead, and a third contact pad, and wherein at least a portion of the third electrode area is overlaid with a reference material.

2. The device of claim 1, wherein said reference material is silver/silver chloride.

3. The device of claim 1, wherein the substrate comprises a flexible material.

4. The device of claim 1, wherein the conductive film is formed from single and multi walled carbon nanotubes and the average outer diameter size of the carbon nanotubes is greater than 0.5 nm.

5. The device of claim 1, wherein said nanotubes are selected from the group consisting of single-walled nanotubes (SWNTs), double-walled nanotubes (DWNTs), multi-walled nanotubes (MWNTs), and mixtures thereof.

6. The device of claim 1, wherein said nanotubes are substantially single-walled nanotubes (SWNTs).

7. The device of claim 1, wherein said nanotubes are present in said film at about 0.001 to about 10% based on weight.

8. The device of claim 1, wherein said nanotubes are present in said film at about 0.5%.

9. The device of claim 1, wherein the film has a surface resistance in the range of less than about 50,000 ohms/square.

10. The device of claim 1, further comprising a polymeric material.

11. The device of claim 1, wherein said nanotubes are selected from the group consisting of single-walled nanotubes (SWNTs), double-walled nanotubes (DWNTs), multi-walled nanotubes (MWNTs), and mixtures thereof to form a dispersion.

12. A device of claim 11, wherein the dispersion comprises a plurality of nanotubes with an outer diameter of less than 10 nm.

13. The device of claim 12, wherein said nanotubes have an outer diameter of about 0.5 to 10 nm.

14. The device of claim 12, wherein said nanotubes are substantially single-walled nanotubes (SWNTs).

15. The device of claim 11, wherein the dispersion further comprising a polymeric material, wherein the polymeric material comprises a material selected from the group consisting of thermoplastics, thermosetting polymers, elastomers, conducting polymers and combinations thereof.

16. The device of claim 11, the dispersion further comprising a polymeric material, wherein the polymeric material comprises a material selected from the group consisting of ceramic hybrid polymers, and phosphine oxides chalcogenides.

17. The device of claim 11, the dispersion further comprising a plasticizer, softening agent, filler, reinforcing agent, processing aid, stabilizer, antioxidant, dispersing agent, binder, a cross-linking agent, a coloring agent, a UV absorbent agent, or a charge adjusting agent.

18. The device of claim 11, the dispersion further comprising conductive organic materials, inorganic materials, or combinations or mixtures thereof.

19. The device of claim 18, wherein the conductive organic materials are selected from the group consisting of buckeyballs, carbon black, fullerenes, nanotubes with an outer diameter of greater than about 0.5 nm, and combinations and mixtures thereof.

20. The device of claim 19, wherein the conductive inorganic materials are selected from the group consisting of antimony tin oxide, iridium tin oxide, aluminum, antimony, beryllium, cadmium, chromium, cobalt, copper, doped metal oxides, iron, gold, lead, manganese, magnesium, mercury, metal oxides, nickel, platinum, silver, steel, titanium, zinc, and combinations and mixtures thereof.

21. The device of claim 20, further comprising a conductive material selected from the group consisting of tin-indium mixed oxide, antimony-tin mixed oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide and combinations and mixtures thereof.

22. The device of claim 20, further comprising conductors, fluids, gelatins, ionic compounds, semiconductors, solids, surfactants, or combinations or mixtures thereof.

23. The device of claim 1, wherein the conductive coating is formed from single and multi walled carbon nanotubes and the average outer diameter size of the carbon nanotubes is less than 10 nm.

24. The device of claim 23, wherein said nanotubes are present in said coating at about 0.001 to about 10% based on weight.

25. The device of claim 23, wherein said nanotubes are present in said coating at about 0.05%.

26. The device of claim 1, wherein said film has a total light transmittance of about 90% or more.

27. The device of claim 1, wherein said film has a total light transmittance of about 95% or more.

28. The device of claim 1, wherein said film has a haze value less than 2.0%.

29. The device of claim 1, wherein said film has a haze value less than 0.1%.

30. The device of claim 1, wherein said film has a thickness between about 0.5 nm to about 1000 microns.

31. The device of claim 1, wherein the nanotubes are oriented.

32. The device of claim 1, wherein the nanotubes are oriented in the plane of the film.

33. The device of claim 1, wherein the nanotubes are oriented, further comprising an additional layer of oriented nanotubes.

34. The device of claim 1, wherein the conductive film of at least one of the working electrode and the counter electrode contains platinum.

35. The device of claim 1, wherein the substrate comprises a polymeric sheet.

36. The device of claim 35, wherein the polymeric sheet material is selected from the group consisting of polyesters, polycarbonates and polyimides.

37. The device of claim 1, wherein the conductive coating is formed with carbon nanotubes and other conductive materials.

38. The device of claim 1, wherein the reagent comprises an enzyme and a redox mediator.

39. The device of claim 38, wherein the enzyme is glucose oxidase.

40. The device of claim 38, wherein the redox mediator is potassium ferricyanide.

41. The device of claim 1, wherein the conductive coating formed with carbon nano tubes and other conductive and non conductive materials has a surface texture less than 0.33 microns.

42. The device of claim 1, wherein the conductive coating formed with carbon nano tubes and other conductive materials has a surface texture less than 0.33 microns.

43. An electrochemical test device for determining the presence or concentration of an analyte in an aqueous fluid sample, said electrochemical test device comprising:

(a) a substrate, the substrate comprising a non-conductive material;

(b) a working electrode comprising a conductive film formed with carbon nanotubes and other conductive and non conductive materials affixed to the non-conductive substrate, said working electrode having a first electrode area, a first lead and a first contact pad;

(c) a counter electrode comprising a conductive film formed with carbon nanotubes and other conductive and non conductive materials affixed to the non-conductive substrate, said counter electrode having a second electrode area, a second lead and a second contact pad;

(d) a reagent capable of reacting with the analyte to produce a measurable change in potential which can be correlated to the presence or concentration of the analyte in the fluid sample, said reagent overlaying at least a portion of the first electrode area of the working electrode; and

wherein at least one of the conductive films forms at least one electrode that has a platinum layer.

44. An electrochemical test device for determining the presence or concentration of an analyte in an aqueous fluid sample, said electrochemical test device comprising:

(a) a substrate, the substrate comprising a non-conductive material;

(b) a working electrode comprising a conductive film formed with carbon nanotubes and other conductive and non conductive materials affixed to the non-conductive substrate, said working electrode having a first electrode area, a first lead and a first contact pad;

(c) a counter electrode comprising an conductive film formed with carbon nanotubes and other conductive and non conductive materials affixed to the non-conductive substrate, said counter electrode having a second electrode area, a second lead and a second contact pad;

(d) a reagent capable of reacting with the analyte to produce a measurable change in potential which can be correlated to the presence or concentration of the analyte in the fluid sample, said reagent overlaying at least a portion of the first electrode area of the working electrode; and

wherein the conductive films are formed with carbon nanotubes and other conductive materials and the leads are formed from coarse solid conductive material.