Spatiotemporal and geometric optimization of sensor arrays for detecting analytes in fluids

• US 7,595,023 B2
• Filed: 07/20/2006
• Issued: 09/29/2009
• Est. Priority Date: 05/10/1999
• Status: Expired due to Fees

• Current Assignee: Aerovironment, California Institute of Technology, University of Florida (State University System of Florida)
• Original Assignee: Aerovironment, California Institute of Technology, University of Florida (State University System of Florida)
• Inventors: Freund, Michael S., Mitchell, David, Briglin, Shawn S., Tokumaru, Phillip, Martin, Charles R., Lewis, Nathan S.
• Primary Examiner(s): Warden; Jill
• Assistant Examiner(s): Hurst; Jonathan M
• Application Number:
  US11/490,732
• Publication Number:
  US 20090214762A1
• Time in Patent Office: 1,167 Days
• Field of Search: 422/50, 422/68.1, 422/88, 422/62, 435/151, 436/55
• US Class Current: 422/62
• CPC Class Codes: G01N 33/0031 comprising two or more sensors, e.g. a sensor array electrochemical electrode arrays G01N27/27
• CPC Class Codes: Y10T 29/49 Method of mechanical manufacture
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 436/11 Automated chemical analysis
• CPC Class Codes: Y10T 436/12 Condition responsive control

Abstract

Sensor arrays and sensor array systems for detecting analytes in fluids. Sensors configured to generate a response upon introduction of a fluid containing one or more analytes can be located on one or more surfaces relative to one or more fluid channels in an array. Fluid channels can take the form of pores or holes in a substrate material. Fluid channels can be formed between one or more substrate plates. Sensor can be fabricated with substantially optimized sensor volumes to generate a response having a substantially maximized signal to noise ratio upon introduction of a fluid containing one or more target analytes. Methods of fabricating and using such sensor arrays and systems are also disclosed.

Claims

1. A method of fabricating a sensor array for detecting an analyte in a fluid, comprising:

providing a substrate having a surface and a sampling headspace proximate to the surface and separated from the environment;

exposing at least one sensing material to at least one target analyte;

identifying a sampling headspace volume V_l for at least a portion of the sampling headspace, and a partition coefficient K of at least one target analyte in the sensing material;

calculating a sensor volume, V_p, based on the sampling headspace volume and the partition coefficient;

and fabricating a sensor by placing the at least one sensing material on the surface proximate to the at least a portion of the sampling headspace, the sensor including an amount of the sensing material derived from the calculated sensor volume.

2. The method of claim 1, wherein:

the sensor volume V_p, is calculated based on the function V_p=V_l/K.

3. The method of claim 1, wherein the sensor volume is optimized to achieve a maximum signal to noise ratio for the at least one target analyte.

4. The method of claim 1, wherein the at least one sensing material comprise a plurality of sensing materials.

5. The method of claim 1, wherein the at least one target analyte comprises a plurality of analytes.

6. The method of claim 1, further comprising forming conductive leads separated by the sensing material.

7. The method of claim 1, wherein the substrate extends parallel to a fluid flow.

8. The method of claim 1, wherein the sensor array comprises two or more optimized sensors.

9. The method of claim 8, wherein the two or more optimized sensor are optimized to respond to different target analytes.

10. The method of claim 1, wherein the substrate is porous.

11. The method of claim 1, wherein the sensing material comprises a conductive polymer.

12. The method of claim 1, wherein the sensing material comprises a mixture of a conductive material and a compositionally different conductive material.

13. The method of claim 12, wherein the conductive material comprises a conductive polymer and the compositionally different conductive material comprises an inorganic conductive material.

14. The method of claim 13, wherein the compositionally different conductive material is selected from the group consisting of a metal, a metal alloy, a semiconductor, a metal oxide, a superconductor, carbon-black and any combination thereof.

15. The method of claim 13, wherein the compositionally different conductive material is a colloidal nanoparticle.

16. The method of claim 13, wherein the compositionally different conductive material is a colloidal nanoparticle and the conducting material is a conductive ligand attached to the nanoparticle.

17. The method of claim 1, wherein the sensing material comprises a nonconductive material and a conductive material.

18. The method of claim 17, wherein the sensing material comprises a conductive material selected from the group consisting of a metal, a metal alloy, a semiconductor, a metal oxide, a superconductor, carbon-black and any combination and the non-conductive material comprises and insulator.

19. The method of claim 1, wherein the sensor is selected from the group consisting of a surface acoustic wave sensor, a quartz crystal resonator, a metal oxide sensor, a dye-coated fiber optic sensor, a dye-impregnated bead array, a micromachined cantilever array, a vapochromic metalloporphyrin, a composite having regions of conducting material and regions of insulating organic material, a composite having regions of conducting material and regions of conducting or semiconducting organic material, a chemically-sensitive resistor or capacitor film, a metal-oxide-semiconductor field effect transistor, and a bulk organic conducting polymeric sensor.