Light addressable electrochemical detection of duplex structures

• US 20030143581A1
• Filed: 09/06/2002
• Published: 07/31/2003
• Est. Priority Date: 07/20/2001
• Status: Active Grant

• Current Assignee: Daniel L. Feldheim, Stefan Franzen
• Original Assignee: Daniel L. Feldheim, Stefan Franzen
• Inventors: Franzen, Stefan, Feldheim, Daniel L.
• Granted Patent: US 7,829,275 B2
• Time in Patent Office: Days
• US Class Current: 435/6
• CPC Class Codes: B82Y 5/00 Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery
• CPC Class Codes: G01N 27/305 optically transparent or photoresponsive electrodes
• CPC Class Codes: G01N 33/54386 Analytical elements
• CPC Class Codes: Y02P 20/133 Renewable energy sources, e.g. sunlight

Abstract

A method of detecting the presence of an analyte, such as a target nucleic acid sequence, protein sequence or small molecule, which can also be employed to detect the formation of duplex structures, is disclosed. The method can comprise nucleic acids, proteins and small molecules, employing photoelectrochemically active nanoparticles, branched polymers or other structures that carry photoelectrochemically active molecules capable of generating a photocurrent when excited by light in the presence of an electric field is disclosed. The method can be employed to detect hybridization on an array and can be employed in sequencing, mutational analysis (for example, single nucleotide polymorphisms and other variations in a population) and for monitoring gene expression by analysis of the level of expression of messenger RNA extracted from a cell. The method is applicable to the detection of antibody binding or other protein binding for analyte detection in an array format. The creation of an array addressable by light is disclosed.

Claims

1. A method of detecting a target analyte comprising:

(a) providing a conductive support comprising a target analyte attached thereto, the target analyte further comprising a nanoparticle comprising a photoelectrochemically active moiety;

(b) exposing the photoelectrochemically active moiety to light, thereby generating a photoelectric current between the photoelectrochemically active moiety and the conductive support; and

(c) measuring the photoelectric current as an indication of the presence or the amount of target analyte on the conductive support.

4. The method of claim 1, wherein the support comprises a material selected from the group consisting of titanium dioxide, tin oxide, silicon, iron^III oxide, silver, nickel, gold, indium tin oxide, conductive polymers, metals, semiconductors and plastics coated with a conductant.

5. The method of claim 1, wherein the support comprises an array of one or more target analytes located at discrete positions on the support

6. The method of claim 5, wherein the one or more target analytes are different from each other.

7. The method of claim 1, wherein the support further comprises a probe, and the target analyte is attached to the support by an interaction with the probe.

8. The method of claim 1, wherein the photoelectric current is an indication of the presence or the amount of the one or more different target analytes.

9. The method of claim 8, wherein the photoelectrochemically active moiety of only one of the different target analytes is exposed to light.

10. The method of claim 1, wherein the target analyte is selected from the group consisting of a single stranded DNA oligomer, a single stranded RNA oligomer, a peptide nucleic acid analog, double stranded DNA, a small molecule, an antibody, a polypeptide, a peptide, a synthesized target analyte, a target analyte isolated from a cell, a target analyte that is reverse transcribed from a nucleic acid sequence, a target analyte comprising intact genomic DNA, a target analyte comprising fragmented genomic DNA, mRNA, a PCR product and an OLA product.

13. The method of claim 1, wherein the photoelectrochemically active moiety comprises a ruthenium center.

14. The method of claim 1, wherein the light is provided by a light source is selected from the group consisting of a tungsten halogen light source, a xenon arc lamp and a laser.

15. The method of claim 1, where in the exposing is by rastering.

16. The method of claim 1, wherein the exposing is performed in the presence of a redox mediator.

17. The method of claim 1, wherein the probe is selected from the group consisting of a single stranded DNA oligomer, a single stranded RNA oligomer, a peptide nucleic acid analog, double stranded DNA, a small molecule, an antibody, a polypeptide, a peptide, a synthesized target analyte, a target analyte isolated from a cell, a target analyte that is reverse transcribed from a nucleic acid sequence, a target analyte comprising intact genomic DNA, a target analyte comprising fragmented genomic DNA, mRNA, a PCR product and an OLA product.

18. The method of claim 17, wherein the probe further comprises a tag sequence.

19. The method of claim 1, further comprising passivating the support with a passivation moiety before contacting the target analyte with the probe under hybridization conditions.

20. The method of claim 19, wherein the passivation moiety comprises a moiety selected from the group consisting of silyl chloride, a sol gel, polyethylene glycol, a thiol, a siloxane, an organic polymer, a carboxylate and combinations thereof.

21. The method of claim 1, further comprising contacting the support with a secondary component after contacting the target analyte with the probe under hybridization conditions.

22. The method of claim 21, wherein the secondary component is a photoelectrochemically active moiety.

23. The method of claim 1, wherein the providing comprises

(a) providing a nanoparticle comprising a target analyte, a central component and a photoelectrochemically active moiety;

(b) providing a probe associated with a support; and

(c) contacting the probe associated with the support with the nanoparticle under hybridization conditions.

24. The method of claim 23, wherein the target analyte is selected from the group consisting of an mRNA sequence derived from a sample to be monitored for gene expression and a cDNA sequence derived from a sample to be monitored for gene expression.

25. The method of claim 24, wherein the probe comprises a gene of interest.

26. The method of claim 24, wherein the presence of a photoelectric current is indicative of duplex formation and duplex formation is indicative of gene expression.

27. The method of claim 1, wherein the providing comprises

(a) providing a nanoparticle comprising a photoelectrochemically active moiety and a target analyte;

(b) providing a probe associated with a support, wherein the probe comprises or is suspected to comprise a mutation to be detected; and

(c) contacting the probe sequence with the target analyte under hybridization conditions.

2. The method of 1, wherein the nanoparticle comprises a material selected from the group consisting of a metal, a metal oxide, a ceramic, a semiconductor, a dendrimer and an organic polymer.

3. The method of claim 2, wherein the nanoparticle comprises a material selected from the group consisting of titanium, titanium dioxide, tin, tin oxide, silicon, silicon dioxide, iron, iron^III oxide, silver, gold, copper, nickel, aluminum, steel, indium, indium tin oxide, fluoride-doped tin, ruthenium oxide, germanium cadmium selenide, cadmium sulfide and titanium alloy.

11. The method of 1, wherein the target analyte is an oligonucleotide whose sequence is determined by surface binding or hybridization

12. The method of claim 11, wherein the target analyte further comprises a tag sequence.