Multi-transduction mechanism based microfluidic analyte sensors

• US 20070042450A1
• Filed: 04/14/2006
• Published: 02/22/2007
• Est. Priority Date: 04/15/2005
• Status: Active Grant

• Current Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG), Worcester Polytechnic Institute
• Original Assignee: Worcester Polytechnic Institute
• Inventors: Benco, John, Lambert, Christopher, Thalladi, Venkat, McGimpsey, W.
• Granted Patent: US 7,935,309 B2
• Time in Patent Office: Days
• US Class Current: 435/14
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• CPC Class Codes: G01N 33/5438 Electrodes

Abstract

In various aspects are provided a microfluidic and/or nanofluidic sensor that can provide an indication of the reliability of its measurement of the presence of an analyte in a sample under investigation, an analyte concentration in the sample under investigation, or both. The provided sensors, microfluidic devices, and methods of analyte detection, utilize two transduction mechanisms from the same molecule to determine analyte presence, analyte concentration, or both. An analyte sensing molecule is used that can provide both an optical signal and electrochemical signal when an analyte is recognized by an analyte binding portion of the sensing molecule.

Claims

1. An analyte sensor comprising:

a substrate having a surface;

an electrically conductive material covering at least a portion of the surface;

an analyte sensor layer covering at least a portion of the electrically conductive material;

the analyte sensor layer comprising analyte sensing molecules, an analyte sensing molecule comprising;

an analyte binding portion;

a fluorophore portion; and

a linker portion connecting the analyte sensing molecule to the electrically conductive material.

2. The analyte sensor of claim 1, wherein the analyte sensor layer is a substantially monolayer thick film.

3. The analyte sensor of claim 1, wherein the substrate comprises a material substantially transparent to one or more of an excitation wavelength and a fluorescence wavelength of the fluorophore portion.

4. The analyte sensor of claim 1, wherein the substrate comprises a silicon dioxide glass material.

5. The analyte sensor of claim 1, wherein the substrate comprises one or more of a polyethylene terephthalate material and a polyethylene naphthalate material.

6. The analyte sensor of claim 1, wherein the electrically conductive material comprises a material substantially transparent to one or more of an excitation wavelength and a fluorescence wavelength of the fluorophore portion.

7. The analyte sensor of claim 1, wherein the electrically conductive material comprises an electrically conductive oxide layer.

8. The analyte sensor of claim 1, wherein the electrically conductive material comprises one or more of indium tin oxide, tin oxide, fluorine-doped tin oxide, tin oxide, and zinc oxide.

9. The analyte sensor of claim 1, wherein the analyte binding portion is an ionophore.

10. The analyte sensor of claim 9, wherein the ionophore comprises a crown ether.

11. The analyte sensor of claim 9, wherein the ionophore comprises an aza crown calixarene.

12. The analyte sensor of claim 9, wherein the ionophore is an ionophore for a monovalent cation selected from the group consisting of:

lithium, sodium, potassium and cesium ions.

13. The analyte sensor of claim 9, wherein the ionophore is an ionophore for a divalent cation selected from the group consisting of:

magnesium, calcium and barium ions.

14. The analyte sensor of claim 9, wherein the ionophore is an ionophore for ammonium ions.

15. The analyte sensor of claim 14, wherein the ionophore is a monocyclic depsipeptide.

16. The analyte sensor of claim 1, wherein the fluorophore portion comprises anthracene.

17. The analyte sensor of claim 1, wherein the fluorophore portion comprises 4,4-difluoro-4-boro-3a,4a-diaza-s-indacene.

18. The analyte sensor of claim 1, wherein the fluorophore portion comprises tetramethylrosamine.

19. The analyte sensor of one or more of claims 14-15, wherein the fluorophore portion comprises aminohodamine B.

20. The analyte sensor of one or more of claims 14-15, wherein the fluorophore portion comprises N-methyl-4-hydrazino-7-nitrobenzofuran.

21. The analyte sensor of claim 1, wherein the analyte binding portion is substantially selective for glucose.

22. The analyte sensor of claim 21, wherein the analyte binding portion comprises a peptide.

23. The analyte sensor of one or more of claims 1-7 and 21-22, wherein the fluorophore portion comprises one or more of nicotinamide adenine dinucleotide (NAD), reduced NDA (NADH) and NAD phosphate (NADP).

24. The analyte sensor of claim 1, wherein the linker portion comprise a C₁₀-C₂₀ alkyl group.

25. The analyte sensor of claim 1, wherein the linker portion comprises one or more of a hexadecyl trialkoxysilyl and hexadecyl trichlorosilyl.

26. An microfluidic device comprising:

a substrate having a surface;

an electrically conductive material covering at least a portion of the surface;

an analyte sensor layer covering at least a portion of the electrically conductive material;

the analyte sensor layer comprising a substantially monolayer thick film of an analyte sensing molecule, the analyte sensing molecule comprising;

an analyte binding portion;

a fluorophore portion; and

a linker portion connecting the analyte sensing molecule to the electrically conductive material;

a reference electrode in electrical contact with the analyte sensor layer; and

a counter electrode in electrical contact with the analyte sensor layer.