Sensor arrays for detecting analytes in fluids

• US 6,010,616 A
• Filed: 12/08/1997
• Issued: 01/04/2000
• Est. Priority Date: 03/27/1995
• Status: Expired due to Term

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Lewis, Nathan S., Freund, Michael S.
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US08/986,500
• Time in Patent Office: 757 Days
• Field of Search: 422/82.01, 422/82.02, 422/82.12, 422/98, 422/68, 422/69, 204/415, 204/418, 204/406, 436/150, 205/787, 205/775, 205/782.5, 73/23.2, 73/23.31, 73/23.34, 73/335.05, 324/691, 324/693, 338/7, 338/13, 338/14
• US Class Current: 205/787
• CPC Class Codes: G01N 27/126 comprising organic polymers
• CPC Class Codes: G01N 33/0031 comprising two or more sensors, e.g. a sensor array
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

A sensor array for detecting an analyte in a fluid, comprising at least first and second chemically sensitive resistors electrically connected to an electrical measuring apparatus, wherein each of the chemically sensitive resistors comprises a mixture of nonconductive material and a conductive material. Each resistor provides an electrical path through the mixture of nonconductive material and the conductive material. The resistors also provide a difference in resistance between the conductive elements when contacted with a fluid comprising an analyte at a first concentration, than when contacted with an analyte at a second different concentration. A broad range of analytes can be detected using the sensors of the present invention. Examples of such analytes include, but are not limited to, alkanes, alkenes, alkynes, dienes, alicyclic hydrocarbons, arenes, alcohols, ethers, ketones, aldehydes, carbonyls, carbanions, polynuclear aromatics, organic derivatives, biomolecules, sugars, isoprenes, isoprenoids and fatty acids. Moreover, applications for the sensors of the present invention include, but are not limited to, environmental toxicology, remediation, biomedicine, material quality control, food monitoring and agricultural monitoring.

Claims

1. A sensor array for detecting an analyte in a fluid, comprising at least first and second chemically sensitive resistors electrically connected to an electrical measuring apparatus, each of said chemically sensitive resistors comprising:

a mixture of nonconductive material and a conductive material compositionally different than said nonconductive material, wherein each resistor provides an electrical path through said mixture of nonconductive material and said conductive material,

a first electrical resistance when contacted with a first fluid comprising a chemical analyte at a first concentration, and

a second electrical resistance when contacted with a second fluid comprising said chemical analyte at a second different concentration,

wherein the difference between the first electrical resistance and the second electrical resistance of said first chemically sensitive resistor being different from the difference between the first electrical resistance and the second electrical resistance of said second chemically sensitive resistor under the same conditions.

2. A sensor array according to claim 1, wherein said conductive material is a member selected from the group consisting of an organic conductor, an inorganic conductor or a mixed inorganic-organic conductor.

3. A sensor array according to claim 2, wherein said conductive material is a member selected from the group consisting of a metal, a metal alloy, a metal oxide, an organic complex, a semiconductor, a superconductor and a mixed inorganic-organic complex.

4. A sensor array according to claim 3, wherein said conductive material is a metal selected from the group consisting of Ag, Au, Cu, Pt, AuCu and mixtures thereof.

5. A sensor array according to claim 3, wherein said conductive material is a particle.

6. A sensor array according to claim 1, wherein said nonconductive material of said first chemically sensitive resistor is different from said second nonconductive material of said second chemically sensitive resistor.

7. A sensor array according to claim 1, wherein said nonconductive material is an organic material.

8. A sensor array according to claim 7, wherein said nonconductive material is an organic polymer.

9. A sensor array according to claim 1, wherein said mixture of nonconductive material and conductive material is fabricated from a member selected from the group consisting of a colloid, a suspension or a dispersion.

10. A sensor array according to claim 9, wherein said mixture of nonconductive material and conductive material is fabricated from a colloid.

11. A sensor array according to claim 10, wherein said conductive material is an inorganic conductor.

12. A sensor array according to claim 11, wherein said inorganic conductor is a particle.

13. A sensor array according to claim 10, wherein said inorganic conductor is a metal selected from the group consisting of Ag, Au, Cu, Pt, AuCu and mixtures thereof.

14. A sensor array according to claim 13, wherein said metal is Au.

15. A system for detecting an analyte in a fluid, said system comprising:

a sensor array comprising at least first and second chemically sensitive resistors, each chemically sensitive resistor comprising a mixture of nonconductive material and a conductive material compositionally different than said nonconductive material, each resistor providing an electrical path through said mixture of nonconducting material and said conductive material, a first electrical resistance when contacted with a first fluid comprising a chemical analyte at a first concentration and a second different electrical resistance when contacted with a second fluid comprising said chemical analyte at a second different concentration, wherein the difference between said first electrical resistance and said second electrical resistance of said first chemically sensitive resistor being different from the difference between said first electrical resistance and said second electrical resistance of said second chemically sensitive resistor under the same conditions;

an electrical measuring device electrically connected to said sensor array; and

a computer comprising a resident algorithm;

said electrical measuring device detecting said first and said second electrical resistances in each of said chemically sensitive resistors and said computer assembling said resistances into a sensor array response profile.

16. A system for detecting an analyte in a fluid according to claim 15, wherein said conductive material is a member selected from the group consisting of an organic conductor, an inorganic conductor or a mixed inorganic-organic conductor.

17. A system for detecting an analyte in a fluid according to claim 16, wherein said conductive material is a member selected from the group consisting of a metal, a metal alloy, a metal oxide, an organic complex, a semiconductor, a superconductor and a mixed inorganic-organic complex.

18. A system for detecting an analyte in a fluid according to claim 17, wherein said conductive material is a metal.

19. A system for detecting an analyte in a fluid according to claim 17, wherein said metal is selected from the group consisting of Ag, Au, Cu, Pt, AuCu and mixtures thereof.

20. A system for detecting an analyte in a fluid according to claim 19, wherein said metal is Au.

21. A system for detecting an analyte in a fluid according to claim 15, wherein said nonconductive material is an organic material.

22. A method for detecting the presence of an analyte in a fluid, said method comprising:

resistively sensing the presence of an analyte in a fluid with a sensor comprising array comprising at least first and second chemically sensitive resistors each comprising a mixture nonconductive material and a conductive material compositionally different than said nonconductive material, each resistor providing an electrical path through said mixture of nonconducting material and said conductive material, a first electrical resistance when contacted with a first fluid comprising a chemical analyte at a first concentration and a second different electrical resistance when contacted with a second fluid comprising said chemical analyte at a second different concentration.

23. A method for detecting the presence of an analyte in a fluid according to claim 22, wherein said conductive material is a member selected from the group consisting of an organic conductor, an inorganic conductor or a mixed inorganic-organic conductor.

24. A method for detecting the presence of an analyte in a fluid according to claim 23, wherein said conductive material is a member selected from the group consisting of a metal, a metal alloy, a metal oxide, an organic complex, a semiconductor, a superconductor and a mixed inorganic-organic complex.

25. A method for detecting the presence of an analyte in a fluid according to claim 24, wherein said conductive material is a particle.

26. A method for detecting the presence of an analyte in a fluid according to claim 24, wherein said conductive material is a metal.

27. A method for detecting the presence of an analyte in a fluid according to claim 26, wherein said metal is selected from the group consisting of Ag, Au, Cu, Pt, AuCu and mixtures thereof.

28. A method for detecting the presence of an analyte in a fluid according to claim 27, wherein said metal is Au.

29. A method for detecting the presence of an analyte in a fluid according to claim 22, wherein said nonconductive material is an organic material.

30. A sensor array for detecting an analyte in a fluid, comprising at least first and second chemically sensitive resistors electrically connected to an electrical measuring apparatus, each of said chemically sensitive resistors comprising:

a plurality of alternating nonconductive regions and conductive regions compositionally different than said nonconductive regions, wherein each resistor provides a transverse electrical path through said plurality of nonconductive regions and said conductive regions.

31. A sensor array according to claim 30, wherein said conductive regions comprise a particle.

32. A sensor array according to claim 31, wherein said particle is a member selected from the group consisting of a metal, a metal alloy, a metal oxide, an organic complex, a semiconductor, a superconductor and a mixed inorganic-organic complex.

33. A sensor array according to claim 32, wherein said conductive material is a metal selected from the group consisting of Ag, Au, Cu, Pt, AuCu and mixtures thereof.

34. A sensor array according to claim 30, wherein said nonconductive region is an organic material.

35. A sensor array for detecting an analyte in a fluid, comprising at least first and second chemically sensitive resistors electrically connected to an electrical measuring apparatus, each of said chemically sensitive resistors comprising:

a plurality of alternating nonconductive regions comprising a nonconductive organic material and conductive regions comprising a conductive material compositionally different than said nonconductive organic material, wherein each resistor provides an electrical path through said plurality of alternating nonconductive regions and said conductive regions,

a first electrical resistance when contacted with a first fluid comprising a chemical analyte at a first concentration, and

a second electrical resistance when contacted with a second fluid comprising said chemical analyte at a second different concentration.

36. A sensor array according to claim 35, wherein said conductive material is a member selected from the group consisting of an organic conductor, an inorganic conductor or a mixed inorganic-organic conductor.

37. A sensor array according to claim 35, wherein said conductive material is a member selected from the group consisting of a metal, a metal alloy, a metal oxide, an organic complex, a semiconductor, a superconductor and a mixed inorganic-organic complex.