Electro-active sensor, method for constructing the same; apparatus and circuitry for detection of electro-active species

• US 7,578,912 B2
• Filed: 12/30/2003
• Issued: 08/25/2009
• Est. Priority Date: 12/30/2002
• Status: Expired due to Fees

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Buehler, Martin
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US10/750,162
• Publication Number:
  US 20050016847A1
• Time in Patent Office: 2,065 Days
• Field of Search: 20440301-40315, 204416-418, 204/412, 205/777.5, 205/778, 205/792
• US Class Current: 204/412
• CPC Class Codes: G01N 27/4035 Combination of a single ion-sensing electrode and a single reference electrode G01N27/406 and G01N27/413 take precedence

Abstract

An electro-active sensor includes a nonconductive platform with a first electrode set attached with a first side of a nonconductive platform. The first electrode set serves as an electrochemical cell that may be utilized to detect electro-active species in solution. A plurality of electrode sets and a variety of additional electrochemical cells and sensors may be attached with the nonconductive platform. The present invention also includes a method for constructing the aforementioned electro-active sensor. Additionally, an apparatus for detection and observation is disclosed, where the apparatus includes a sealable chamber for insertion of a portion of an electro-active sensor. The apparatus allows for monitoring and detection activities. Allowing for control of attached cells and sensors, a dual-mode circuitry is also disclosed. The dual-mode circuitry includes a switch, allowing the circuitry to be switched from a potentiostat to a galvanostat mode.

Claims

1. An electro-active sensor for detecting electro-active species in solution, comprising:

a nonconductive platform, the nonconductive platform having a first side and a second side;

a first electrode set attached with the first side of the nonconductive platform, wherein the first electrode set further comprises;

a first conductive via passing through the nonconductive platform from the first side to the second side;

a first electrode attached with the first conductive via on the first side, where the first electrode serves as a first working electrode;

a second conductive via passing through the nonconductive platform from the first side to the second side;

a second electrode attached with the second conductive via on the first side, where the second electrode serves as a first reference electrode;

a third conductive via passing through the nonconductive platform from the first side to the second side; and

a third electrode attached with the third conductive via on the first side, where the third electrode serves as an first auxiliary electrode, whereby the working electrode, the reference electrode, and the auxiliary electrode serve as a electrochemical cell that may be utilized to detect the electro-active species in the solution;

wherein the first auxiliary electrode from the first electrode set is connected with a second auxiliary electrode from a second electrode set; and

wherein the first and second auxiliary electrodes are connected with a common ground.

2. An electro-active sensor as set forth in claim 1, wherein the electro-active sensor further comprises a plurality of electrode sets.

3. An electro-active sensor as set forth in claim 2, wherein the electro-active sensor further comprises electrical connectors connected with the vias on the second side of the nonconductive platform, whereby the electrical connectors may be connected with a monitoring apparatus, allowing for monitoring of the electro-active species in the solution.

4. An electro-active sensor as set forth in claim 3, wherein the nonconductive platform is constructed of a material selected from a group consisting of ceramic and glass.

5. An electro-active sensor as set forth in claim 4, wherein the electrodes are all formed in a substantially co-planar manner.

6. An electro-active sensor as set forth in claim 5, wherein the electrical connectors are substantially co-planar and a plane of the electrical connectors is parallel with respect to a plane of the nonconductive platform.

7. An electro-active sensor as set forth in claim 6, wherein at least a portion of each electrode in the electrode set is formed in a shape selected from a group consisting of a ring and a disk.

8. An electro-active sensor as set forth in claim 7, wherein each electrode set is formed such that the electrodes in the electrode set are concentric.

9. An electro-active sensor as set forth in claim 8, wherein the reference electrode surrounds the working electrode, and the auxiliary electrode surrounds the reference electrode.

10. An electro-active sensor as set forth in claim 9, wherein the electro-active sensor further comprises a biofilm attached with the first side of the nonconductive platform.

11. An electro-active sensor as set forth in claim 10, wherein the electro-active sensor further comprises an Ion Selective Sensor attached with the first side of the nonconductive platform.

12. An electro-active sensor as set forth in claim 11, wherein the Ion Selective Sensor is a pH sensor.

13. An electro-active sensor as set forth in claim 12, wherein the electro-active sensor further comprises a four-terminal conductivity sensor attached with the first side of the nonconductive platform, thereby allowing for a measurement of a conductivity of the solution.

14. An electro-active sensor as set forth in claim 13, wherein the electro-active sensor further comprises a two-terminal heater attached with the nonconductive platform, thereby allowing the electro-active sensor to be heated to varying temperatures.

15. An electro-active sensor as set forth in claim 14, wherein the electro-active sensor further comprises a two-terminal temperature sensor attached with the nonconductive platform, thereby allowing for monitoring of a temperature of the electro-active sensor.

16. An electro-active sensor as set forth in claim 15, wherein the electro-active sensor further comprises circuitry attached with the electrical connectors, the circuitry further comprising:

a potentiostat circuit portion attached with an electrochemical cell, the electrochemical cell comprising a grounded auxiliary electrode, a reference electrode, and a working electrode, whereby when activated, the potentiostat circuit portion forces a voltage between the working electrode and the reference electrode;

a feedback circuit connected with the potentiostat circuit portion, whereby when the potentiostat circuit portion is activated, the feedback circuit adjusts a current though the electrochemical cell accordingly;

a galvanostat circuit portion attached with the electrochemical cell, whereby the galvanostat circuit portion forces a current through the electrochemical cell and when the galvanostat circuit portion is activated the feedback circuit adjusts a voltage between the working electrode and the reference electrode; and

a switch circuit connected with the potentiostat circuit portion and galvanostat circuit portion, allowing for the activation of the potentiostat or galvanostat circuit portion.

17. An electro-active sensor as set forth in claim 1, wherein the electro-active sensor further comprises electrical connectors connected with the vias on the second side of the nonconductive platform, whereby the electrical connectors may be connected with a monitoring apparatus, allowing for monitoring of the electro-active species in the solution.

18. An electro-active sensor as set forth in claim 17, wherein the electrical connectors are substantially co-planar and a plane of the electrical connectors is parallel with respect to a plane of the nonconductive platform.

19. An electro-active sensor as set forth in claim 1, wherein the nonconductive platform is constructed of a material selected from a group consisting of ceramic and glass.

20. An electro-active sensor as set forth in claim 1, wherein the electrodes are all formed in a substantially co-planar manner.

21. An electro-active sensor as set forth in claim 1, wherein at least a portion of each electrode in the electrode set is formed in a shape selected from a group consisting of a ring and a disk.

22. An electro-active sensor as set forth in claim 1, wherein each electrode set is formed such that the electrodes in the electrode set are concentric.

23. An electro-active sensor as set forth in claim 1, wherein the reference electrode surrounds the working electrode, and the auxiliary electrode surrounds the reference electrode.

24. An electro-active sensor as set forth in claim 1, wherein the electro-active sensor further comprises a biofilm attached with the first side of the nonconductive platform.

25. An electro-active sensor as set forth in claim 1, wherein the electro-active sensor further comprises an Ion Selective Sensor attached with the first side of the nonconductive platform.

26. An electro-active sensor as set forth in claim 25, wherein the Ion Selective Sensor is a pH sensor.

27. An electro-active sensor as set forth in claim 1, wherein the electro-active sensor further comprises a four-terminal conductivity sensor attached with the first side of the nonconductive platform, thereby allowing for a measurement of a conductivity of the solution.

28. An electro-active sensor as set forth in claim 1, wherein the electro-active sensor further comprises a two-terminal heater attached with the nonconductive platform, thereby allowing the electro-active sensor to be heated to varying temperatures.

29. An electro-active sensor as set forth in claim 1, wherein the electro-active Sensor further comprises a two-terminal temperature sensor attached with the nonconductive platform, thereby allowing for monitoring of a temperature of the electro-active sensor.

30. An electro-active sensor as set forth in claim 1, wherein the electro-active sensor further comprises circuitry attached with the electrical connectors, the circuitry further comprising:

a potentiostat circuit portion attached with an electrochemical cell, the electrochemical cell comprising a grounded auxiliary electrode, a reference electrode, and a working electrode, whereby when activated, the potentiostat circuit portion forces a voltage between the working electrode and the reference electrode;

a feedback circuit connected with the potentiostat circuit portion, whereby when the potentiostat circuit portion is activated, the feedback circuit adjusts a current though the electrochemical cell accordingly;

a galvanostat circuit portion attached with the electrochemical cell, whereby the galvanostat circuit portion forces a current through the electrochemical cell and when the galvanostat circuit portion is activated the feedback circuit adjusts a voltage between the working electrode and the reference electrode; and

a switch circuit connected with the potentiostat circuit portion and galvanostat circuit portion, allowing for the activation of the potentiostat or galvanostat circuit portion.