Redox mediators
View Patent ↗The present application is generally directed to ruthenium or osmium containing complexes and their use as redox mediators in electrochemical biosensors.
1. A complex according to Formula I
[M(A) x (B) y ] m (X Z ) n Formula I
wherein
M is ruthenium or osmium and has an oxidation state of 0, 1, 2, 3 or 4;
x, and n are independently an integer selected from 1 to 6; y is an integer selected from 1 to 5; m is an integer from −5 to +4 and z is an integer from −2 to +1;
A is a mono- or bidentate aromatic ligand containing 1 or 2 nitrogen atoms;
B is independently selected to be one or more ligands other than a heterocyclic nitrogen-containing ligand;
X comprises a combination of PF 6 − and CF 3 SO 3 − counterions;
wherein A is optionally substituted by 1 to 8 groups independently selected from the group consisting of substituted or unsubstituted alkyl, alkenyl, or aryl groups, —F, —Cl, —Br, —I, —NO 2 , —CN, —CO 2 H, —SO 3 H, —NHNH 2 , —SH, alkoxycarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, —OH, alkoxy, —NH 2 , alkylamino, dialkylamino, alkanoylamino, arylcarboxamido, hydrazino, alkylhydrazino, hydroxylamino, alkoxyamino, and alkylthio;
wherein the number of coordination atoms is 6.
2. A redox mediator comprising the complex as claimed in claim 1 .
3. The redox mediator as claimed in claim 2 wherein A is a monodentate ligand substituted by one or more CO 2 H groups, or a bidentate ligand optionally substituted by one or more CO 2 H groups.
4. The redox mediator as claimed in claim 2 wherein A is selected from the group consisting of nicotinic acid, isonicotinic acid, 2,2′ bipyridine, 2,2-bipyridyl-5,5′-dicarboxylic acid, 2,2-bipyridyl-4,4′-dicarboxylic acid, and 5-chloro-8-hydroxyquinoline.
5. The redox mediator as claimed in claim 2 wherein B is selected from the group consisting of amine ligands, CO, CN, halogen, acetylacetonate, 3-bromoacetylacetonate, oxalate, pyridine, and 5-chloro-8-hydroxyquinoline.
6. The redox mediator as claimed in claim 2 wherein the oxidation state of the metal is selected to be 3+.
7. The redox mediator as claimed in claim 2 wherein the ligands A and B are selected such that the overall charge on the complex is selected from the group consisting of +3, +2, +1, 0, −1, −2 and −3.
8. A complex as claimed in claim 1 wherein A is a monodentate ligand substituted by one or more CO 2 H groups, or a bidentate ligand optionally substituted by one or more CO 2 H groups wherein said one or more CO 2 H groups are each in a meta position relative to the co-ordinating heteroatom or heteroatoms.
9. A complex as claimed in claim 1 wherein A is selected from the group consisting of nicotinic acid, isonicotinic acid, 5-carboxynicotinic acid, 6-pyridyl-nicotinic acid, 2,2′-bipyridine-5,5′-bis-carboxylic acid, 2,2′-bipyridine-4,4′-bis-carboxylic acid, 2,2′-bipyridine, and 1,10-phenanthroline-3,9-bis-carboxylic acid.
10. A complex as claimed in claim 1 wherein B is selected from the group consisting of amine ligands; CO; CN; halogen, acetylacetonate, 3-bromoacetylacetonate, oxalate, and 5-chloro-8-hydroxyquinoline.
11. A complex as claimed in claim 1 wherein the ligands A and B are selected such that the overall charge on the complex is selected from the group consisting of +2, +1, 0, −1, −2 and −3.
12. A complex as claimed in claim 1 wherein said complex is [Ru III (NH 3 ) 5 (pyridine-3-COOH)](PF 6 ) 2 (CF 3 SO 3 ).
13. The redox mediator as claimed in claim 2 wherein said complex is [Ru III (NH 3 ) 5 (pyridine-3-COOH)](PF 6 ) 2 (CF 3 SO 3 ).
14. A complex according to Formula I
[M(A) x (B) y ] m (X Z ) n Formula I
wherein
M is ruthenium or osmium and has an oxidation state of 0, 1, 2, 3 or 4;
x, and n are independently an integer selected from 1 to 6; y is an integer selected from 1 to 5; m is an integer from −5 to +4 and z is an integer from −2 to +1;
A is a mono- or bidentate aromatic ligand containing 1 or 2 nitrogen atoms;
B is independently selected to be one or more ligands other than a heterocyclic nitrogen-containing ligand;
X comprises a combination of two PF 6 − counterions and one CF 3 SO 3 − counterion;
wherein A is optionally substituted by 1 to 8 groups independently selected from the group consisting of substituted or unsubstituted alkyl, alkenyl, or aryl groups, —F, —Cl, —Br, —I, —NO 2 , —CN, —CO 2 H, —SO 3 H, —NHNH 2 , —SH, alkoxycarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, —OH, alkoxy, —NH 2 , alkylamino, dialkylamino, alkanoylamino, arylcarboxamido, hydrazino, alkylhydrazino, hydroxylamino, alkoxyamino, and alkylthio;
wherein the number of coordination atoms is 6.