Multimode electrochemical sensing array

• US 7,323,091 B1
• Filed: 09/24/2003
• Issued: 01/29/2008
• Est. Priority Date: 09/24/2002
• Status: Active Grant

• Current Assignee: Thermo Orion, Inc. (Thermo Fisher Scientific Incorporated)
• Original Assignee: Orion Research, Inc. (Thermo Fisher Scientific Incorporated)
• Inventors: Gillette, Timothy C., West, Steven J.
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US10/669,454
• Time in Patent Office: 1,588 Days
• Field of Search: 204/412, 204/461, 204/417, 204/418, 204/416, 257/253
• US Class Current: 204/416
• CPC Class Codes: G01N 27/414 Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS

Abstract

A multimode electrochemical sensing array formed on an integrated circuit chip is structured to provide electrochemical determination of acidity or alkalinity, as well as electrochemical and potentiometric measurement of oxidation/reduction potentials, conductivity measurements, electrostatic discharge protection, and ground provisioning.

Claims

1. A multimode electrochemical sensing array comprising a semiconductor chip having formed thereon:

A. an Ion Selective Field Effect Transistor, said transistor having an exposed Gate for contact with a test solution when immersed therein, said Gate being surrounded by, but spaced from, a conductive surface that serves as both an electrode and a light shield for the transistor;

B. a plurality of electrodes spaced remotely from said transistor, at least one of said electrodes being connectable in circuit with said conductive surface and with an external current source to provide a current for electrochemical determination of two or more parameters of said solution.

2. A multimode electrochemical sensing array according to claim 1 in which said current source is polarized to provide a titrant in the vicinity of said Gate.

3. A multimode electrochemical sensing array according to claim 1 in which said current source is polarized to provide a titrant in the vicinity of said at least one remotely spaced electrode.

4. A multimode electrochemical sensing array according to claim 1 in which said remotely spaced electrodes includes comprise a first pair of electrodes, each of a first area, and a second pair of electrodes, each of a smaller area than said first area, said electrodes being connectable in circuit with an external current source and an external voltage meter to provide conductivity measurements of a test solution in which they are immersed.

5. A multimode electrochemical sensing array according to claim 1 in which said remotely spaced electrodes include at least one electrode for performing oxidation/reduction measurements with respect to an external reference electrode.

6. A multimode electrochemical sensing array according to claim 1 in which said remotely spaced electrodes include at least one electrode connectable through a potential regulating element to said conductive surface for limiting the potential on said surface.

7. A multimode electrochemical sensing array according to claim 6 in which said potential regulating element comprises a varistor.

8. A multimode electrochemical sensing array according to claim 1 in which said remotely spaced electrodes include at least one electrode connectable to ground to thereby connect a test solution to ground potential when desired.

9. A multimode electrochemical sensing array according to claim 1 in which said at least one electrode is connectable in circuit with an external source of constant current.

10. A multimode electrochemical sensing array according to claim 1 in which said at least one electrode is connectable in circuit with an external source of current that increases during its application.

11. A multimode electrochemical sensing array according to claim 1 in which said at least one electrode is connectable in circuit with an external source of current that increases linearly during its application over at least some range thereof.