Detection of analytes using reorganization energy
The invention relates to novel methods and compositions for the detection of analytes using the nuclear reorganization energy, λ, of an electron transfer process.
1. A method of detecting a target analyte in a test sample, said method comprising:
(1) adding a target analyte to a composition comprising an electrode, said electrode comprising:
(a) a redox active complex comprising:
(i) a first species comprising a redox active molecule, said redox active molecule comprising at least one polar ligand and a transitional metal selected from the group consisting of manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver and gold; and
(ii) a second species comprising a binding ligand, wherein said first species and said second species are attached to a spacer and said spacer is attached to said electrode, and
(b) a self-assembled monolayer; and
(2) detecting said target analyte.
2. The method according to claim 1 , wherein said metal is iron.
3. The method according to claim 1 , wherein said metal is ruthenium.
4. The method according to claim 1 , wherein said metal is osmium.
5. The method according to claim 1 , wherein the attachment of said first species and said second species has a configuration of:
wherein the hashed mark represents said electrode, M is said metal, L is a co-ligand, n is each independently 0 or 1 with the proviso that there is at least one L, X is a spacer, BL is said binding ligand, F 1 is a linkage that allows the covalent attachment of said electrode and said spacer, and F 2 is a linkage that allows the covalent attachment of said spacer to said redox active complex, and wherein said F 1 X, and F 2 can be independently the same or different for the attachment of said M and said BL.
6. The method according to claim 1 , wherein said polar ligand comprises a cyano group.
7. The method according to claim 1 , wherein said polar ligand comprises an amine group.
8. The method according to claim 1 , wherein said electrode is gold and said first species and said second species are covalently attached to said electrode via sulfur atoms.
9. The method according to claim 1 , wherein said self-assembled monolayer comprises a conductive oligomer.
10. The method according to claim 1 , wherein said self-assembled monolayer comprises an insulator.
11. The method according to claim 10 , wherein said insulator comprises a C1-C20 alkyl group.
12. The method according to claim 10 , wherein said insulator comprises a C1-C12 alkyl group.
13. The method according to claim 1 , wherein said spacer is an insulator.
14. The method according to claim 1 , wherein said spacer is a conductive oligomer.
15. The method according to claim 1 , wherein said binding ligand is a protein.
16. The method according to claim 15 , wherein said protein is a peptide.
17. The method according to claim 1 , wherein said target analyte is an enzyme and said binding ligand is a substrate of said enzyme.