PHOTOELECTROCATALYTIC FLUID ANALYTE SENSORS AND METHODS OF FABRICATING AND USING SAME

• US 20080220535A1
• Filed: 05/07/2007
• Published: 09/11/2008
• Est. Priority Date: 01/11/2007
• Status: Active Grant

• Current Assignee: Valencell, Inc.
• Original Assignee: Valencell, Inc.
• Inventors: LeBoeuf, Steven Francis, Aumer, Michael Edward, Tucker, Jesse Berkley
• Granted Patent: US 8,323,982 B2
• Time in Patent Office: Days
• US Class Current: 436/164
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G01N 27/305 optically transparent or photoresponsive electrodes
• CPC Class Codes: G01N 27/414 Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS
• CPC Class Codes: Y10T 436/11 Automated chemical analysis
• CPC Class Codes: Y10T 436/17 Nitrogen containing
• CPC Class Codes: Y10T 436/235 In an aqueous solution [e.g., TOC, etc.]
• CPC Class Codes: Y10T 436/25 including sample preparation
• CPC Class Codes: Y10T 436/25375 Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]
• CPC Class Codes: Y10T 436/25875 Gaseous sample or with change of physical state

Abstract

Fluid analyte sensors include a photoelectrocatalytic element that is configured to be exposed to the fluid, if present, and to respond to photoelectrocatalysis of at least one analyte in the fluid that occurs in response to impingement of optical radiation upon the photoelectrocatalytic element. A semiconductor light emitting source is also provided that is configured to impinge the optical radiation upon the photoelectrocatalytic element. Related solid state devices and sensing methods are also described.

Claims

1. A fluid analyte sensor, comprising:

a photoelectrocatalytic element that is configured to be exposed to the fluid, if present, and to respond to photoelectrocatalysis of at least one analyte in the fluid that occurs in response to impingement of optical radiation upon the photoelectrocatalytic element; and

a semiconductor light emitting source that is configured to impinge the optical radiation upon the photoelectrocatalytic element.

2. A sensor according to claim 1 wherein the photoelectrocatalytic element comprises a photoelectrocatalytic layer and at least one conductive contact electrically connected thereto.

3. A sensor according to claim 1 wherein the photoelectrocatalytic element comprises a plurality of spaced apart photoelectrocatalytic layers and a plurality of spaced apart conductive contacts electrically connected thereto.

4. A sensor according to claim 1 wherein the photoelectrocatalytic element comprises a reference electrode and/or a charge balancing electrode.

5. A sensor according to claim 1 further comprising a substrate, and wherein the photoelectrocatalytic element and the semiconductor light emitting source are at least partially monolithically integrated with the substrate.

6. A sensor according to claim 1 wherein the fluid comprises a liquid and/or a gas and wherein the analyte comprises a pollutant, contaminant and/or a component of the fluid.

7. A sensor according to claim 1 wherein the fluid comprises respired gas and wherein the analyte comprises a component of the respired gas.

8. A sensor according to claim 1 wherein the semiconductor light emitting source comprises a laser diode and/or a light emitting diode.

9. A sensor according to claim 1 wherein the photoelectrocatalytic element is configured to respond to photoelectrocatalysis of at least one analyte in the fluid by changing a conductivity, capacitance, inductance, impedance, net charge, optical property and/or mechanical property thereof in response to the impingement of optical radiation upon the photoelectrocatalytic element.

10. A sensor according to claim 1 wherein the photoelectrocatalytic element further comprises a transistor, a capacitor, a nanostructure, a diode, an amorphous structure, a piezoelectric structure, a surface acoustic wave structure and/or a heating element.

11. A sensor according to claim 1 wherein the photoelectrocatalytic element and the semiconductor light emitting source include at least one common electrical contact.

12. A sensor according to claim 1 wherein the semiconductor light emitting source includes a passivation layer and wherein the photoelectrocatalytic element is at least partially on the passivation layer.

13. A sensor according to claim 1 further comprising a photodetector that is configured to detect the optical radiation that is emitted by the semiconductor light emitting source and/or optical radiation emitted by the photoelectrocatalysis.

14. A sensor according to claim 1 further comprising a controller that is configured to selectively energize the semiconductor light emitting source and to detect a response to the photoelectrocatalysis of at least one analyte in the fluid that occurs in response to impingement of optical radiation upon the photoelectrocatalytic element.

15. A sensor according to claim 1 wherein the photoelectrocatalytic element is doped with deep level impurities and wherein the semiconductor light emitting source is a visible and/or infrared light emitting diode and/or laser diode.

16. A sensor according to claim 1 wherein the photoelectrocatalytic element comprises a metal oxide, wherein the semiconductor light emitting source comprises an ultraviolet and/or blue light emitting diode and/or laser diode.

17. A sensor according to claim 1 further comprising a monitor that is configured to monitor the response to the at least one analyte in the fluid, if present, resulting from the photoelectrocatalysis of the at least one analyte in response to impingement of optical radiation upon the photoelectrocatalytic element.

18. A sensor according to claim 1 further comprising a monitor that is configured to monitor energy of the at least one analyte in the fluid, if present, resulting from the photoelectrocatalysis of the at least one analyte in response to impingement of optical radiation upon the photoelectrocatalytic element.

19. A sensor according to claim 2 wherein the photoelectrocatalytic layer comprises a plurality of layers of a given photoelectrocatalytic material having at least two different impurities therein.

20. A sensor according to claim 2 wherein the photoelectrocatalytic layer comprises a plurality of layers of different photoelectrocatalytic materials.

21. A sensor according to claim 2 wherein the photoelectrocatalytic layer comprises oxide, carbide, nitride, arsenide, phosphide, sulfide and/or antimonide photoelectrocatalytic compounds and/or metal oxides, metal nitrides, metallic compounds and/or semimetallic compounds thereof.

22. A sensor according to claim 2 wherein the at least one conductive contact comprises at least two interdigitated conductive contacts.

23. A sensor according to claim 14 wherein the controller is configured to repeatedly modulate the semiconductor light emitting source and to detect an electrical response of the at least one photoelectrocatalytic element in response thereto.

24. A sensor according to claim 14 further comprising a wireless transmitter that is responsive to the controller.

25. A sensor according to claim 17 wherein the monitor is configured to monitor an electrical, electromagnetic, mechanical, acoustic and/or thermal response to the at least one analyte in the fluid.

26. A sensor according to claim 18 wherein the monitor is configured to monitor the energy as optical energy of the at least one analyte in the fluid.

35. A device according to claim 26 wherein the semiconductor light emitting source includes a passivation layer and wherein the photoelectrocatalytic element is at least partially on the passivation layer.

27. A solid state device comprising:

a photoelectrocatalytic element;

a semiconductor light emitting source; and

a housing that is configured to position the photoelectrocatalytic element and the semiconductor light emitting source relative to one another such that the semiconductor light emitting source impinges optical radiation on the photoelectrocatalytic element upon electrical energization of the electro-optical source.

28. A device according to claim 27 wherein the photoelectrocatalytic element comprises a photoelectrocatalytic layer and an electrical contact layer thereon and wherein the semiconductor light emitting source comprises a light emitting diode and/or a laser diode.

29. A device according to claim 28 wherein the photoelectrocatalytic layer includes first and second opposing faces, wherein the electrical contact layer is on the first face and wherein the light emitting diode impinges optical radiation on the first face and/or on the second face.

30. A device according to claim 27 wherein the photoelectrocatalytic element comprises a photoelectrocatalytic layer and at least one conductive contact electrically connected thereto.

31. A device according to claim 27 wherein the photoelectrocatalytic element comprises a plurality of spaced apart photoelectrocatalytic layers and a plurality of spaced apart conductive contacts electrically connected thereto.

32. A device according to claim 27 wherein the photoelectrocatalytic element comprises a reference electrode and/or a charge balancing electrode.

33. A device according to claim 27 wherein the photoelectrocatalytic element further comprises a transistor, a capacitor, a nanostructure, a diode, an amorphous structure, a piezoelectric structure, a surface acoustic wave structure and/or a heating element.

34. A device according to claim 27 wherein the photoelectrocatalytic element and the semiconductor light emitting source include at least one common electrical contact.

36. A device according to claim 27 further comprising a controller that is configured to selectively energize the semiconductor light emitting source and to detect a response to the impingement of optical radiation upon the photoelectrocatalytic element.

37. A device according to claim 27 wherein the photoelectrocatalytic element is doped with deep level impurities and wherein the semiconductor light emitting source is a visible and/or infrared light emitting diode and/or laser diode.

38. A device according to claim 27 wherein the photoelectrocatalytic element comprises a metal oxide, wherein the semiconductor light emitting source comprises an ultraviolet and/or a blue light emitting diode and/or laser diode.

39. A device according to claim 28 wherein the photoelectrocatalytic layer comprises a plurality of layers of a given photoelectrocatalytic material having at least two different impurities therein.

40. A device according to claim 28 wherein the photoelectrocatalytic layer comprises a plurality of layers of different photoelectrocatalytic materials.

41. A device according to claim 28 wherein the photoelectrocatalytic layer comprises oxide, carbide, nitride, arsenide, phosphide, sulfide and/or antimonide photoelectrocatalytic compounds and/or metal oxides, metal nitrides, metallic compounds and/or semimetallic compounds thereof.

42. A device according to claim 28 wherein the electrical contact comprises at least two interdigitated conductive contacts.

43. A device according to claim 36 wherein the controller is configured to repeatedly modulate the semiconductor light emitting source and to detect an electrical response of the photoelectrocatalytic element in response thereto.

44. A device according to claim 36 further comprising a wireless transmitter that is responsive to the controller.

45. A sensing method, comprising:

energizing a semiconductor light emitting source to impinge optical radiation upon a photoelectrocatalytic element that is configured to be exposed to a fluid, if present; and

detecting a response of the photoelectrocatalytic element in response to the energizing of the semiconductor light emitting source.

46. A method according to claim 45 wherein the fluid comprises a liquid and/or a gas and wherein the analyte comprises a pollutant, contaminant and/or a component of the fluid.

47. A method according to claim 45 wherein the fluid comprises respired gas and wherein the analyte comprises a component of the respired gas.

48. A method according to claim 45 wherein detecting a response of the photoelectrocatalytic element comprises detecting a change in a conductivity, capacitance, inductance, impedance, net charge, optical property and/or mechanical property of the photoelectrocatalytic element in response to the impingement of optical radiation upon the photoelectrocatalytic element.

49. A method according to claim 45 further comprising:

monitoring energy of the at least one analyte in the fluid, if present, resulting from the photoelectrocatalysis of the at least one analyte in response to impingement of optical radiation upon the photoelectrocatalytic element.

50. A method according to claim 45 wherein energizing a semiconductor light emitting source comprises repeatedly modulating the semiconductor light emitting source.

51. A method according to claim 45 further comprising repelling charged analyte from the photoelectrocatalytic element.

52. A method according to claim 45 further comprising biasing the photoelectrocatalytic element to reduce carrier recombination.