Photoelectrocatalytic fluid analyte sensors and methods of fabricating and using same

• US 8,323,982 B2
• Filed: 05/07/2007
• Issued: 12/04/2012
• Est. Priority Date: 01/11/2007
• Status: Expired due to Fees

• Current Assignee: Valencell, Inc.
• Original Assignee: Valencell, Inc.
• Inventors: LeBoeuf, Steven Francis, Tucker, Jesse Berkley, Aumer, Michael Edward
• Primary Examiner(s): WHITE, DENNIS MICHAEL
• Application Number:
  US11/745,056
• Publication Number:
  US 20080220535A1
• Time in Patent Office: 2,038 Days
• Field of Search: 422/82.05, 422/82.06, 422/82.07, 422/52, 422/73, 422/82.01, 422/82.02, 422/82.08, 422/82.09, 422/82.11, 422/407, 422/501, 422/502, 422/503, 422/504, 422/507, 436/164, 436/172, 436/43, 436/62, 436/63, 436/106, 436/146, 436/149, 436/174, 436/177, 436/181, 436/518, 436/805, 436/809, 435/29, 435/4, 435/6, 435/7.1, 435/7.92, 435/7.94, 435/287.2, 435/288.7, 506/7, 506/30, 250/208.1, 250/214.1, 250/251, 250/576, 250/373, 250/458.1, 530/408, 356/417, 356/419, 356/496, 73/232, 73/310.3, 204/157.15, 204/192.21, 204/403.01, 204/403.14, 205/777.5
• 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:

an array of photoelectrocatalytic elements, a respective one of which 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 respective photoelectrocatalytic element;

an array of semiconductor light emitting sources, a respective one of which is configured to impinge the optical radiation upon the respective one of the photoelectrocatalytic elements; and

an array of heaters that is separate from the array of semiconductor light emitting sources, a respective one of the heaters being configured and independently regulated to separately generate thermal energy and apply the thermal energy to only the respective photoelectrocatalytic element so as to affect interaction between the at least one analyte and the array of photoelectrocatalytic elements.

2. A sensor according to claim 1 wherein the array of photoelectrocatalytic elements comprises a photoelectrocatalytic layer and a plurality of conductive contacts electrically connected thereto.

3. A sensor according to claim 1 wherein the array of photoelectrocatalytic elements 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 array of photoelectrocatalytic elements comprises a reference electrode and/or a charge balancing electrode.

5. A sensor according to claim 1 further comprising a substrate, and wherein the array of photoelectrocatalytic elements, the array of semiconductor light emitting sources and the array of heaters 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 array of semiconductor light emitting sources comprises an array of laser diodes and/or light emitting diodes.

9. A sensor according to claim 1 wherein the array of photoelectrocatalytic elements 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 thermal energy and the impingement of optical radiation upon the photoelectrocatalytic element.

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

11. A sensor according to claim 1 wherein the array of photoelectrocatalytic elements and the array of semiconductor light emitting sources include at least one common electrical contact.

12. A sensor according to claim 1 wherein the array of semiconductor light emitting sources includes a passivation layer and wherein the array of photoelectrocatalytic elements 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 array of semiconductor light emitting sources 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 array of semiconductor light emitting sources and the array of heaters and to detect a response to the photoelectrocatalysis of at least one analyte in the fluid that occurs in response to the thermal energy and the impingement of optical radiation upon the photoelectrocatalytic element.

15. A sensor according to claim 1 wherein the array of photoelectrocatalytic elements is doped with deep level impurities and wherein the array of semiconductor light emitting sources is an array of visible and/or infrared light emitting diodes and/or laser diodes.

16. A sensor according to claim 1 wherein the array of photoelectrocatalytic elements comprises a metal oxide, wherein the array of semiconductor light emitting sources comprises an array of ultraviolet and/or blue light emitting diodes and/or laser diodes.

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 the thermal energy and the impingement of optical radiation upon the array of photoelectrocatalytic elements.

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 the thermal energy and the impingement of optical radiation upon the array of photoelectrocatalytic elements.

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 array of semiconductor light emitting sources 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.

53. A sensor according to claim 1 wherein the array of heaters is configured to apply thermal energy to the array of photoelectrocatalytic elements so that the array of photoelectrocatalytic elements also responds to thermocatalysis of the at least one analyte in the fluid.

54. A sensor according to claim 1 wherein the array of heaters is configured to apply a thermal gradient in at least one direction along the array of photoelectrocatalytic elements.

55. A sensor according to claim 1 wherein the array of heaters comprises an array of filament heaters, monolithic patterned resistors, resistive heaters and/or radiative heaters.

56. A sensor according to claim 54 wherein the array of heaters comprises one or more array of localized filament heaters, monolithic patterned resistors, radiative heaters and/or graded filament heaters.

57. A sensor according to claim 1 wherein the array of heaters comprises an array of infrared heaters.

58. A sensor according to claim 1 wherein the array of photoelectrocatalytic elements comprises a plurality of photoelectrocatalytic electrodes and wherein the array of heaters comprises a plurality of heaters, a respective one of which is configured to apply the thermal energy to a respective one of the photoelectrocatalytic electrodes.

59. A sensor according to claim 1 wherein the array of heaters comprises a film that generates the thermal energy in response to impingement of light thereon.

27. A solid state device comprising:

an array of photoelectrocatalytic elements;

an array of semiconductor light emitting sources;

an array of heaters that is separate from the array of semiconductor light emitting sources; and

a housing that is configured to position a respective one of the array of photoelectrocatalytic elements, a respective one of the array of semiconductor light emitting sources and a respective one of the array of heaters relative to one another such that the respective one of the semiconductor light emitting sources impinges optical radiation on the respective one of the photoelectrocatalytic elements upon electrical energization of the respective semiconductor light emitting source and a the respective one of the heaters is independently regulated separately to generate thermal energy and apply the thermal energy to only the respective one of the photoelectrocatalytic elements upon electrical energization of the respective heater.

28. A device according to claim 27 wherein the array of photoelectrocatalytic elements comprises a photoelectrocatalytic layer and an electrical contact layer thereon and wherein the array of semiconductor light emitting source sources comprises an array of light emitting diodes and/or laser diodes.

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 array of light emitting diodes impinges optical radiation on the first face and/or on the second face.

30. A device according to claim 27 wherein the array of photoelectrocatalytic elements comprises a photoelectrocatalytic layer and a plurality of conductive contacts electrically connected thereto.

31. A device according to claim 27 wherein the array of photoelectrocatalytic elements 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 array of photoelectrocatalytic elements comprises a reference electrode and/or a charge balancing electrode.

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

34. A device according to claim 27 wherein the array of photoelectrocatalytic elements and the array of semiconductor light emitting sources include at least one common electrical contact.

35. A device according to claim 27 wherein the array of semiconductor light emitting sources includes a passivation layer and wherein the array of photoelectrocatalytic elements is at least partially on the passivation layer.

36. A device according to claim 27 further comprising a controller that is configured to selectively energize the array of semiconductor light emitting sources and the array of heaters and to detect a response to the thermal energy and the impingement of optical radiation upon the array of photoelectrocatalytic elements.

37. A device according to claim 27 wherein the array of photoelectrocatalytic elements is doped with deep level impurities and wherein the array of semiconductor light emitting sources is an array of visible and/or infrared light emitting diodes and/or laser diodes.

38. A device according to claim 27 wherein the array of photoelectrocatalytic elements comprises a metal oxide, wherein the array of semiconductor light emitting sources comprises an array of ultraviolet and/or a blue light emitting diodes and/or laser diodes.

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 array of semiconductor light emitting sources 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.

60. A device according to claim 27 wherein the array of heaters is configured to apply a thermal gradient in at least one direction along the array of photoelectrocatalytic elements.

61. A device according to claim 27 wherein the array of heaters comprises an array of filament heaters, monolithic patterned resistors, resistive heaters and/or radiative heaters.

62. A device according to claim 60 wherein the array of heaters comprises one or more arrays of localized filament heaters, monolithic patterned resistors, radiative heaters and/or graded filament heaters.

63. A device according to claim 27 wherein the array of heaters comprises an array of infrared heaters.

64. A device according to claim 27 wherein the array of photoelectrocatalytic elements comprises a plurality of photoelectrocatalytic electrodes and wherein the array of heaters comprises a plurality of heaters, a respective one of which is configured to apply the thermal energy to a respective one of the photoelectrocatalytic electrodes.

65. A device according to claim 27 wherein the array of heaters comprises a film that generates the thermal energy in response to impingement of light thereon.

45. A sensing method, comprising:

energizing a respective one of an array of semiconductor light emitting sources to impinge optical radiation upon a respective one of an array of photoelectrocatalytic elements that is configured to be exposed to a fluid, if present, so that the respective one of the array of semiconductor light emitting sources impinges the optical radiation on the respective one of the array of photoelectrocatalytic elements;

energizing a respective one of an array of heaters that is separate from the array of semiconductor light emitting sources and is independently regulated to separately generate thermal energy and apply the thermal energy to the array of photoelectrocatalytic elements, so that the respective one of the heaters applies the thermal energy to only the respective one of the array of photoelectrocatalytic elements; and

detecting a response of the array of photoelectrocatalytic elements in response to the energizing of the array of semiconductor light emitting sources and the array of heaters.

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 array of photoelectrocatalytic elements comprises detecting a change in a conductivity, capacitance, inductance, impedance, net charge, optical property and/or mechanical property of the array of photoelectrocatalytic elements in response to the thermal energy and the impingement of optical radiation upon the array of photoelectrocatalytic elements.

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 the thermal energy and the impingement of optical radiation upon the array of photoelectrocatalytic elements.

50. A method according to claim 45 wherein energizing an array of semiconductor light emitting sources comprises repeatedly modulating the semiconductor light emitting source.

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

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