Biological identification system with integrated sensor chip

• US 7,399,585 B2
• Filed: 05/03/2001
• Issued: 07/15/2008
• Est. Priority Date: 05/03/2000
• Status: Expired due to Term

• Current Assignee: Department of Health and Human Services (State of Victoria)
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Gau, Vincent Jen-Jr.
• Primary Examiner(s): Epperson; Jon D.
• Assistant Examiner(s): Lundgren; Jeffrey S.
• Application Number:
  US09/848,727
• Publication Number:
  US 20020123048A1
• Time in Patent Office: 2,630 Days
• Field of Search: 435/4, 435/7.1, 435/287.1, 435/287.2, 435/287.8, 436/149, 436/150
• US Class Current: 435/6.11
• CPC Class Codes: B01J 2219/00317 Microwell devices, i.e. having large numbers of wells
• CPC Class Codes: B01J 2219/00497 Features relating to the solid phase supports
• CPC Class Codes: B01J 2219/00585 Parallel processes
• CPC Class Codes: B01J 2219/00596 Solid-phase processes
• CPC Class Codes: B01J 2219/00605 the compounds being directly bound or immobilised to solid supports
• CPC Class Codes: B01J 2219/0061 The surface being organic
• CPC Class Codes: B01J 2219/00612 the surface being inorganic
• CPC Class Codes: B01J 2219/00617 by chemical means
• CPC Class Codes: B01J 2219/00619 using hydrophilic or hydrophobic regions
• CPC Class Codes: B01J 2219/00621 by physical means, e.g. trenches, raised areas
• CPC Class Codes: B01J 2219/0063 Other, e.g. van der Waals forces, hydrogen bonding
• CPC Class Codes: B01J 2219/00637 by coating it with another layer
• CPC Class Codes: B01J 2219/00653 the compounds being bound to electrodes embedded in or on the solid supports
• CPC Class Codes: B01J 2219/00659 Two-dimensional arrays
• CPC Class Codes: B01J 2219/00702 Processes involving means for analysing and characterising the products
• CPC Class Codes: B01J 2219/00722 Nucleotides
• CPC Class Codes: B01J 2219/00725 Peptides
• CPC Class Codes: B01L 3/5088 confining liquids at a location by surface tension, e.g. virtual wells on plates, wires B01L3/50857 takes precedence
• CPC Class Codes: B81C 2201/0133 Wet etching
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C12Q 1/68 : involving nucleic acids
• CPC Class Codes: C12Q 1/6876 : Nucleic acid products used in the analysis of nucleic acids, e.g. primers or probes
• CPC Class Codes: C12Q 2600/156 : Polymorphic or mutational markers
• CPC Class Codes: C40B 40/06 : Libraries containing nucleotides or polynucleotides, or derivatives thereof
• CPC Class Codes: C40B 40/10 : Libraries containing peptides or polypeptides, or derivatives thereof
• CPC Class Codes: C40B 60/14 : for creating libraries
• CPC Class Codes: G01N 27/3277 : being a redox reaction, e.g. detection by cyclic voltammetry voltammetry per se G01N27/42, G01N27/48

Abstract

The system includes a microfabricated electrochemical biosensor for detecting the presence and/or quantity of the target analyte in the sample reagent. The biosensor includes a substrate and at least two electrically conductive electrodes. Each of the electrical conductive electrodes consists of a single layer of an electrically conductive material. The electrodes can be fabricated on the substrate by integrated circuit technology.

Claims

1. A method of detecting the presence or measuring the quantity of a target analyte in a sample, comprising:

positioning the sample on a sensor, the sensor including a working electrode, a reference electrode and a counter electrode on a substrate, the reference electrode consisting of a single layer of an electrically conductive material and a self-assembly monolayer, the self-assembly monolayer being bonded to the layer of electrically conductive material and including biotinylated thiol molecules that include a sulfur bonded directly to the layer of electrically conductive material;

conducting an analysis of the sample that includes controlling a potential difference between the reference electrode and the working electrode while measuring a current flowing through the working electrode, wherein

the potential is controlled so as to cause a redox reaction between a component in the sample and the working electrode, and

the current through the working electrode is balanced by a current through the counter electrode; and

employing the measured current to determine the presence or quantity of a target analyte in the sample.

2. The method of claim 1, wherein the sensor includes an adhesive underneath each of the electrodes, the adhesive allowing for better adhesion of each of the electrodes to the substrate.

3. The method of claim 1, wherein the sample is a biological fluid containing macromolecules.

4. The method of claim 1, wherein the sample is a biological fluid containing ionic molecules or atoms.

5. The method of claim 1, wherein the substrate is selected from the group consisting of silicon, gallium arsenide, plastic and glass.

6. The method of claim 1, wherein the substrate comprises a material made out of silicon.

7. The method of claim 1, wherein the electrically conductive material is selected from the group consisting of gold, aluminum, chromium, copper, platinum, titanium, nickel and titanium.

8. The method of claim 1, wherein the electrically conductive material is gold.

9. The method of claim 2, wherein the adhesive is selected from the group of consisting of chromium, titanium, and glue.

10. The method of claim 2, wherein the adhesive includes chromium.

11. The method of claim 1, wherein the substrate further includes a well structure containing at least one of the electrodes.

12. The method of claim 1, wherein each of the electrically conductive electrodes consists of a single layer of gold.

13. The method of claim 1, further comprising:

calibrating the sensor with a first calibrating solution that contains a known amount of a target analyte to be detected and a second calibrating solution that contains an undetectable amount of the target analyte to be detected.

14. The method of claim 1, wherein a surface on at least one of the electrodes is modified for anchoring molecules on the surface.

15. The method of claim 1, wherein the electrodes are in contact with the substrate.

16. The method of claim 1, wherein the electrically conductive material associated with each electrode extends from each electrode to an electrical pad positioned on the substrate.

17. The method of claim 1, wherein each of the electrodes is constructed of the same material.

18. The method of claim 9, wherein the reference electrode and the counter electrode each have a shape that is different from a shape of the working electrode.

19. The method of claim 1, wherein the sample is a liquid.

20. The method of claim 1, wherein positioning the sample on the sensor includes forming a drop of the sample over the electrodes.

21. The method of claim 1, wherein the potential difference between the working electrode and the reference electrode is controlled by application of a current through the counter electrode.

22. The method of claim 1, wherein the sensor consists of the working electrode, counter electrode and reference electrode positioned on the substrate.

23. The method of claim 1, wherein the sensor occupies an area of 160 μ

m² to 25 mm².

24. The method of claim 1, wherein the analysis is a cyclic voltammetry analysis.

25. The method of claim 1, wherein the analysis is an amperometric analysis.

26. The method of claim 1, wherein controlling the potential difference between the working electrode and the reference electrode includes sweeping the potential difference between the working electrode and the reference electrode across a range of values.

27. The method of claim 1, wherein the analysis includes measuring the current between the counter electrode and the working electrode while sweeping the potential difference between the working electrode and the reference electrode across a range of values.

28. The method of claim 1, wherein the reference electrode, the working electrode and the counter electrode each consist of a single layer of an electrically conducting material.

29. The method of claim 1, wherein the self-assembly monolayer is positioned on the working electrode.

30. The method of claim 1, wherein the reference electrode is arranged about the perimeter of the working electrode such that a portion of the working electrode is positioned between different regions of the reference electrode.

31. The method of claim 1, wherein the counter electrode is arranged about the perimeter of the working electrode such that a portion of the working electrode is positioned between different regions of the reference electrode.

32. The method of claim 1, wherein employing the measured current to determine the presence or quantity of a target analyte in the sample includes employing the potential in combination with the measured current to determine the presence or quantity of the target analyte in the sample.

33. The method of claim 1, further comprising:

forming the self-assembly monolayer on at least one of the electrodes before positioning the sample on the sensor.

34. The method of claim 29, further comprising:

forming the self-assembly monolayer on the working electrode before positioning the sample on the sensor.

35. The method of claim 1, wherein the self-assembly monolayer is positioned on the working electrode, and the counter electrode, the self-assembly monolayer including biotinylated thiol molecules bonded to the counter electrode and the working electrode.

36. The method of claim 35, further comprising:

forming the self-assembly monolayer on the working electrode, the counter electrode, and the reference electrode before positioning the sample on the sensor.

37. The method of claim 35, wherein a portion of the biotinylated thiol molecules include a sulfur that is bonded directly to the working electrode and another portion of the biotinylated thiol molecules include a sulfur that is bonded directly to the counter electrode.

38. The method of claim 1, wherein the self-assembly monolayer is positioned on at least the reference electrode, the self-assembly monolayer including biotinylated thiol molecules bonded to at least the reference electrode.

39. The method of claim 1, wherein the self-assembly monolayer is positioned on the working electrode, the self-assembly monolayer including biotinylated thiol molecules bonded to the working electrode.