Mediators suitable for the electrochemical regeneration of NADH, NADPH or analogs thereof

• US 5,520,786 A
• Filed: 06/06/1995
• Issued: 05/28/1996
• Est. Priority Date: 06/06/1995
• Status: Expired due to Term

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Corporation (Bayer AG)
• Inventors: Siegmund, Hans-Ulrich, Murray, Alison J., Musho, Matthew K., Deng, Yingping, Corey, Paul F., Bloczynski, Michael L.
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US08/471,745
• Time in Patent Office: 357 Days
• Field of Search: 429/42, 429/43, 204/403
• US Class Current: 204/403.14
• CPC Class Codes: C12Q 1/004 mediator-assisted
• CPC Class Codes: H01M 4/9008 Organic or organo-metallic compounds
• CPC Class Codes: H01M 8/16 Biochemical fuel cells, i.e. cells in which microorganisms function as catalysts
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

Disclosed is an improved electrode suitable for the electrochemical regeneration of the co-enzymes NADH and NADPH. The electrode has imparted on its surface a mediator function which is a 3-phenylimino-3H-phenothiazine or a 3-phenylimino-3H-phenoxazine. Also disclosed is a method of improving the performance of a biochemical fuel cell which operates with a dehydrogenase as a catalyst and a co-enzyme as the energy-transferring redox couple which involves using the improved electrode in the fuel cell.

Claims

1. An electrode for the electrochemical regeneration of the coenzymes dihydronicotinamide adenine dinucleotide (NADH), dihydronicotinamide adenine dinucleotide phosphate (NADPH) or analogs thereof characterized in that there has been imparted to the electrode surface a mediator function comprising one or more mediator compound selected from the group of substituted or unsubstituted 3-phenylimino-3H-phenothiazines and 3-phenylimino-3H-phenoxazines.

2. An electrode as in claim 1 wherein the mediator is characterized by Formula I or Formula II:

##STR30## wherein R1 and R2 are substituents which serve to modulate the reduction-oxidation (redox) potential of the mediator, to vary the mediator'"'"'s solubility or to function as a site for the covalent attachment of the mediator to a polymer or solid support.

3. The electrode of claim 2 wherein R1 and R2, which may be the same or different, are selected from the group consisting of hydrogen, lower alkyl, aryl, halo, haloalkyl, carboxy, carboxyalkyl, alkoxycarbonyl, aryloxycarbonyl, aromatic and aliphatic keto, alkoxy, aryloxy, nitro, dialkylamino, aminoalkyl, sulfo and dihydroxyboron wherein the aliphatic and aromatic groups are substituted or unsubstituted.

4. The electrode of claim 1 wherein the electrode material is graphite, pyrolytic carbon, glassy carbon, platinum, gold or a composite made from these materials.

5. The electrode of claim 1 wherein the mediator is attached to a polymer.

6. The electrode of claim 5 wherein the polymer is poly(methylvinyl ether-co-maleic anhydride).

7. The electrode of claim 1 wherein the mediator is selected from the group comprised of:

3-(4'"'"'-chloro-phenylimino)-3H-phenothiazine,

3-(4'"'"'-diethylamino-phenylimino)-3H-phenothiazine,

3-(4'"'"'-ethyl-phenylimino)-3H-phenothiazine,

3-(4'"'"'-trifluoromethyl-phenylimino)-3H-phenothiazine,

3-(4'"'"'-methoxycarbonyl-phenylimino)-3H-phenothiazine,

3-(4'"'"'-nitro-phenylimino)-3H-phenothiazine,

3-(4'"'"'-methoxy-phenylimino)-3H-phenothiazine,

7-acetyl-3-(4'"'"'-methoxycarbonylphenylimino)-3H-phenothiazine,

7-trifluoromethyl-3-(4'"'"'-methoxycarbonylphenylimino)-3H-phenothiazine,

3-(4'"'"'-ω

-carboxy-n-butyl-phenylimino)-3H-phenothiazine,

3-(4'"'"'-aminomethyl-phenylimino)-3H-phenothiazine,

3-(4'"'"'-(2"-(5"-(p-aminophenyl)-1,3,4-oxadiazoyl)phenylimino)-3H-phenothiazine,

3-(4'"'"'-β

-aminoethyl-phenylimino)-3H-phenothiazine,

6-(4'"'"'-ethylphenyl)amino-3-(4'"'"'-ethyl-phenylimino)-3H-phenothiazine,

6-(4'"'"'-[2-(2-ethanoloxy)ethoxy]ethoxyphenyl)amino-3-(4'"'"'-[2-(2-ethanoloxy)ethoxy]ethoxy-phenylimino)-3H-phenothiazine,

3-(4'"'"'-[2-(2-ethanoloxy)ethoxy]ethoxy-phenylimino)-3H-phenothiazine,

3-(4'"'"'-phenylimino)-3H-phenothiazineboronic acid,

(3-(3'"'"',5'"'"'-dicarboxy-phenylimino)-3H-phenothiazine,

3-(4'"'"'-carboxy-phenylimino)-3H-phenothiazine,

3-(3'"'"',5'"'"'-dicarboxy-phenylimino)-3H-phenoxazine,

3-(2'"'"',5'"'"'-phenylimino)-3H-phenothiazinedisulfonic acid, and

3-(3-phenylimino)-3H-phenothiazinesulfonic acid.

8. The electrode of claim 7 wherein the mediator is 3-(4'"'"'-trifluoromethyl-phenylimino)-3H-phenothiazine.

9. The electrode of claim 7 wherein the mediator is 3-(4'"'"'-methoxycarbonyl-phenylimino)-3H-phenothiazine.

10. The electrode of claim 7 wherein the mediator is 3-(4'"'"'-ω

-carboxy-n-butyl-phenylimino)-3H-phenothiazine.

11. The electrode of claim 7 wherein the mediator is 3-(4'"'"'-aminomethyl-phenylimino)-3H-phenothiazine.

12. The electrode of claim 7 wherein the mediator is 3-(4'"'"'-β

-aminoethyl-phenylimino)-3H-phenothiazine.

13. The electrode of claim 7 wherein the mediator is 3-(3'"'"',5'"'"'-dicarboxy-phenylimino)-3H-phenothiazine.

14. The electrode of claim 7 wherein the mediator is 3-(3'"'"',5'"'"'-dicarboxy-phenylimino)-3H-phenoxazine

15. The electrode of claim 7 wherein the mediator is 3-(2'"'"',5'"'"'-phenylimino)-3H-phenothiazinedisulfonic acid.

16. The electrode of claim 7 wherein the mediator is 3-(3'"'"'-phenylimino)-3H-phenothiazinesulfonic acid.

17. The electrode of claim 5 wherein the mediator is 3-(4'"'"'-aminomethyl-phenylimino)-3H-phenothiazine or 3-(4'"'"'-β

-aminoethyl-phenylimino)-3H-phenothiazine.

18. The electrode of claim 6 wherein the mediator is 3-(4'"'"'-aminomethyl-phenylimino)-3H-phenothiazine or 3-(4'"'"'-β

-aminoethyl-phenylimino)-3H-phenothiazine.