Biomolecular sensors and detection methods utilizing photoinduced charge separation

• US 20050255515A1
• Filed: 06/14/2005
• Published: 11/17/2005
• Est. Priority Date: 03/28/2002
• Status: Abandoned Application

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Inaoka, Seiji, Roitman, Daniel B., Ach, Robert A., Tom-Moy, May
• Application Number:
  US11/153,000
• Publication Number:
  US 20050255515A1
• Time in Patent Office: Days
• US Class Current: 435/6
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings

Abstract

The invention provides methods and sensors for detecting target biological molecules. Biosensors feature photoactivatable charge separation moieties capable of generating electron-hole pairs upon photoinduction. Photoinduced charge carriers participate in redox reactions that are detectable, for example, by optical, chemical, or electronic means.

Claims

1. A method of detecting a target biomolecule in a sample, comprising:

(a) labeling said target biomolecule with a photoinducible charge-separation moiety to produce a labeled target molecule;

(b) contacting said labeled target biomolecule with a substrate bound to a probe biomolecule for said target;

(c) contacting said substrate with an electron acceptor that is detectably reduced by said charge-separation moiety if said charge-separation moiety is photoinduced; and

(d) photoinducing said charge-separation moiety provide a detectable reduced electron acceptor; and

(e) detecting said detectable reduced electron acceptor.

2. The method of claim 1, wherein the charge separation moiety comprises a metal oxide nanoparticle.

3. The method of claim 2, wherein the charge-separation moiety is selected from the group consisting of TiO₂, SnO₂, and WO₃.

4. The method of claim 1, wherein the charge-separation moiety further comprises a dopant that modifies the bandgap energy.

5. The method of claim 4, wherein the charge-separation moiety further comprises Al₂O₃, SiO₂, Ta₂O₅, Nb₂O₅, or ZrO₂.

6. The method of claim 2, wherein the metal oxide nanoparticle size ranges between about 20 nm to about 40 nm.

7. The method of claim 1, wherein the electron acceptor comprises a metal ion capable of providing a detectable change in optical absorption or reflection upon photoreduction.

8. The method of claim 7, wherein the metal ion is selected from the group consisting of Ag⁺, Pt⁺⁴, Au⁺², Hg⁺², Cu⁺² and Cr⁺⁴.

9. The method of claim 1, wherein the electron acceptor comprises an anode.

10. The method of claim 9, wherein the anode comprises indium tin oxide (ITO), gold, silver, or silicon.

11. The method of claim 1, which further comprises a mediator in solution.

12. The method of claim 11, wherein the mediator is selected from the group consisting of a quinone, an organic conducting salt, and a viologen dye.

13. The method of claim 1, wherein the probe and target molecules are complementary nucleic acids.

14. The method of claim 1, wherein the probe is an antibody and said target is an antigen.

15. The method of claim 1, wherein the substrate is a flexible membrane.

26. The sensor of claim 1, which further comprises a mediator in solution.

27. The sensor of claim 26, wherein the mediator is selected from the group consisting of a quinone, an organic conducting salt, and a viologen dye.

16. A sensor for detecting a target biomolecule bound to a probe biomolecule on a substrate, comprising:

a photoinducible charge-separation moiety that effects charge-separation upon photoinduction,

an electron donor, and

an electron acceptor;

wherein the electron acceptor is capable of providing detectable photoreduction indicating the presence of the bound target molecule upon excitation of the charge-separation moiety.

17. The sensor of claim 16, wherein the charge separation moiety comprises a metal oxide nanoparticle.

18. The sensor of claim 17, wherein the charge-separation moiety is selected from the group consisting of TiO₂, SnO₂, and WO₃.

19. The sensor of claim 16, wherein the charge-separation moiety further comprises a dopant that modifies the bandgap energy.

20. The sensor of claim 19, wherein the charge-separation moiety further comprises Al₂O₃, SiO₂, Ta₂O₅, Nb₂O₅, or ZrO₂.

21. The sensor of claim 17, wherein the metal oxide nanoparticle size ranges between about 20 nm to about 40 nm.

22. The sensor of claim 16, wherein the electron acceptor comprises a metal ion capable of providing a detectable change in optical absorption or reflection upon photoreduction.

23. The sensor of claim 22, wherein the metal ion is selected from the group consisting of Ag⁺, Pt⁺⁴, Au⁺², Hg⁺², Cu⁺² and Cr⁺⁴.

24. The sensor of claim 16, wherein the electron acceptor comprises an anode.

25. The sensor of claim 24, wherein the anode comprises indium tin oxide (ITO), gold, silver, or silicon.

28. The sensor of claim 16, wherein the probe and target molecules are complementary nucleic acids.

29. The sensor of claim 16, wherein the probe is an antibody and said target is an antigen.

30. The sensor of claim 29, wherein the substrate is a flexible membrane.