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 comprising
a) adding a target analyte to an electrode comprising
i) a solvent accessible transition metal complex comprising a 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 binding ligand that will bind said target analyte; such that upon binding of said target analyte to said binding ligand, a solvent inhibited transition metal complex is formed; and
b) measuring a change in E 0 of said transition metal complex.
2. A method according to claim 1 , wherein said measuring comprises applying at least a first input signal to said solvent inhibited transition metal complex and receiving an output signal.
3. A method according to claim 2 , wherein in the absence of target analyte, said output signal does not indicate a significant change in E 0 .
4. A method according to claim 2 , wherein said first input signal comprised at least an AC component.
5. A method according to claim 2 , further comprising applying input signal at a plurality of frequencies.
6. A method according to claim 2 or 4 , wherein said input signal comprises at least a DC component.
7. A method according to claim 6 , further comprising applying input signal at a plurality of voltages.
8. A method according to claim 2 , wherein said output signal is a current.
9. A method according to claim 8 , wherein said current is an AC current.
10. A method according to claim 1 wherein said electrode surface comprises gold.
11. A method according to claim 1 wherein said electrode further comprises a self-assembled monolayer.
12. A method according to claim 11 wherein said self assembled monolayer comprises conductive oligomers.
13. A method according to claim 1 , wherein said solvent accessible transition metal complex has at least one coordination site occupied by a polar coordination group.
14. A method according to claim 1 , wherein said solvent accessible transition metal complex has at least one coordination site occupied by a water molecule.
15. A method according to claim 1 , wherein said solvent accessible transition metal complex has at least two coordination sites occupied by a polar coordination group.
16. A method according to claim 1 , wherein said binding ligand is covalently attached to said solvent accessible transition metal complex.
17. A method according to claim 1 , wherein said binding ligand is covalently attached to said electrode.
18. A method according to claim 1 , wherein said solvent accessible transition metal complex is covalently attached to said electrode.
19. A method according to claim 17 , wherein said covalent attachment is via a spacer.
20. A method according to claim 18 , wherein said covalent attachment is via a spacer.
21. A method according to claim 19 or 20 , wherein said spacer is a conductive oligomer.