Detection of analytes using reorganization energy

1. A method of detecting a target analyte in a test sample, said method comprising:

(1) adding a target analyte to an electrode comprising a redox active complex, said 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 metal selected from the group consisting of manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver and gold;

(ii) a second species comprising a binding ligand that will bind to said target analyte, such that upon binding of said target analyte to said binding ligand, there is a change of the E 0 of said redox active molecule,

wherein said first species and said second species sterically close to the first species are attached separately to said electrode; and

(2) measuring said change in the E 0 of said redox active complex.

2. The method according to claim 1 , wherein said metal is osmium.

3. The method according to claim 1 , wherein said redox active molecule comprises at least one polar ligand.

4. The method according to claim 3 , wherein said polar ligand is a small polar ligand.

5. The method according to claim 1 , wherein said redox active molecule comprises a cyano group.

6. The method according to claim 1 , wherein said binding ligand is a protein.

7. The method according to claim 6 , wherein said protein is a peptide.

8. The method according to claim 1 , wherein said binding ligand is a substrate of an enzyme.

9. The method according to claim 1 , wherein said attachment is via a spacer.

10. The method according to claim 9 , wherein said spacer is an insulator.

11. The method according to claim 9 , wherein said spacer is a conductive oligomer.

12. The method according to claim 1 , wherein said measuring step is carried out using voltammetry.