Multilayered structure comprising an enzyme layer
A multilayered structure suitable as an electrode in a power source and a method of producing the same. The structure comprises a conductive laminar layer; and an enzyme layer containing an essentially dry enzyme capable of oxidizing or dehydrogenating carbohydrate material under suitable conditions. Because the enzymatic anode layer and the fuel containing layer are not interacting during the production and since they are kept latent during storage time, the power source will remain stable for extended periods of time, thus increasing the utility of the power source.
1. A multilayered structure suitable as an electrode in a power source, comprising;
a conductive laminar layer,
a laminar enzyme layer containing an essentially dry enzyme capable of oxidizing or dehydrogenating carbohydrate material, and
a laminar fuel layer containing a source of chemical energy comprising an essentially dry carbohydrate material, wherein said laminar fuel layer essentially abuts with said laminar enzyme layer or wherein said laminar fuel layer is separated from said laminar enzyme layer by a laminar intermediate layer to form said multilayered structure.
2. The multilayered structure according to claim 1 , wherein said laminar fuel layer is separated from said laminar enzyme layer by said laminar intermediate layer, said laminar intermediate layer being configured to transfer water to said laminar enzyme layer when wetted.
3. The multilayered structure according to claim 1 , wherein said laminar fuel layer stands in direct contact with said laminar enzyme layer.
4. The multilayered structure according to claim 2 , wherein said laminar intermediate layer, capable of being wetted, is placed between said laminar fuel layer and said laminar enzyme layer.
5. The multilayered structure according to claim 2 , wherein said laminar intermediate layer is porous.
6. The multilayered structure according to claim 5 , wherein said laminar intermediate layer comprises a porous substrate selected from the group consisting of: porous fibrous webs and sheets of natural or synthetic origin.
7. The multilayered structure according to claim 1 , wherein said laminar enzyme layer is deposited on a first laminar substrate layer.
8. The multilayered structure according to claim 7 , wherein said laminar fuel layer is deposited on a second laminar substrate layer.
9. The multilayered structure according to claim 1 , further comprising a surface layer formed by a membrane permeable to ions.
10. The multilayered structure according to claim 9 , wherein the membrane forms a first laminar substrate layer and said laminar enzyme layer is deposited on the first laminar substrate layer.
11. The multilayered structure according to claim 8 , wherein said second laminar substrate layer is formed by a sheet of paper, cardboard or plastics, which is essentially impermeable to moisture.
12. The multilayered structure according to claim 1 , wherein said enzyme is mixed with an electron transfer mediator.
13. The multilayered structure according claim 1 , wherein said enzyme is selected from the group consisting of peroxidases and oxidases.
14. The multilayered structure according to claim 13 , wherein said enzyme is selected from the group consisting of laccases (EC 1.10.3.2), catechol oxidases (EC 1.10. 3.1), tyrosinases (EC 1.14. 18.1), bilirubin oxidases (EC 1.3.3.5), peroxidase (EC 1.11.1.7), manganase peroxidase (EC 1.11.1.13), lignin peroxidase (EC 1.11.1.14), cytochrome-c oxidase (1.9.3.1), L-ascorbate oxidase (1.10.3.3) and ceruloplasmin (1.16.3.1).
15. The multilayered structure according to claim 14 , wherein said enzyme has an activity of about 1 to 100,000 nkat/g, and it is employed in an amount of 0.0001 to 10 mg protein/g of dry matter of said laminar enzyme layer.
16. The multilayered structure according to claim 13 , wherein said enzyme has a redox potential, expressed as V vs. NHE, of at least 0.3.
17. The multilayered structure according to claim 16 , wherein said enzyme is selected from the group consisting of laccase from Melanocarpus (EC 1.10.3.2), laccase from Trametes (EC 1.10.3.2), laccase from Pycnoporus (EC 1.10.3.2), laccase from Rhizoctonia (EC 1.10.3.2), laccase from Coprinus (EC 1.10.3.2), laccase from Myceliophtora (EC 1.10.3.2), laccase from Pleurotus (EC 1.10.3.2), laccase from Rhus (EC 1.10.3.2), laccase from Agaricus (EC 1.10.3.2), laccase from Aspergillus (EC 1.10.3.2), laccase from Cerrena (EC 1.10.3.2), laccase from Curvularia (EC 1.10.3.2), laccase from Fusarium (EC 1.10.3.2), laccase from Lentinius (EC 1.10.3.2), laccase from Monocillium (EC 1.10.3.2), laccase from Myceliophtora (EC 1.10.3.2), laccase from Neurospora (EC 1.10.3.2), laccase from Penicillium (EC 1.10.3.2), laccase from Phanerochaete (EC 1.10.3.2), laccase from Phlebia (EC 1.10.3.2), laccase from Podospora (EC 1.10.3.2), laccase from Schizophyllum (EC 1.10.3.2), laccase from Sporotrichum (EC 1.10.3.2), laccase from Stagonospora (EC 1.10.3.2) laccase from Chaetomium (EC 1.10.3.2), laccase from Bacillus (EC 1.10.3.2), laccase from Azospirillum (EC 1.10.3.2) and laccase from Trichoderma (EC 1.10.3.2).
18. The multilayered structure according to claim 12 , wherein said electron transfer mediator is selected from the group consisting of ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)], methyl syringate [methyl 3,5-dimethoxy-4-hydroxybenzoate], other methoxy or dimethoxy phenols, ferrocenecarboxyaldehyde, other ferrocene derivates, and mixtures thereof.
19. The multilayered structure according to claim 12 , wherein said electron transfer mediator is present in a concentration of 0.001 to 10.0 wt-% of said laminar enzyme layer.
20. The multilayered structure according to claim 1 , wherein said laminar enzyme layer further contains a conductive ink.
21. The multilayered structure according to claim 20 , wherein said conductive ink comprises a binder and an electrically conductive component selected from the group consisting of carbon nanotubes, metal particles, carbon particles, inherently conductive polymers, and mixtures thereof.
22. The multilayered structure according to claim 1 , wherein said conductive laminar layer is formed by printing or coating to provide a layer having an average thickness of between 20 nm to 100 um.
23. The multilayered structure according to claim 1 , wherein said laminar fuel layer contains a source of chemical energy selected from the group consisting of mono- and disaccharides.
24. The multilayered structure according to claim 23 , wherein said laminar fuel layer contains a monosaccharide selected from the group consisting of xylose, glucose, galactose and fructose.
25. The multilayered structure according to claim 1 , wherein said laminar enzyme layer has a moisture content of less than 10% by weight.
26. The multilayered structure according to claim 1 , wherein said laminar fuel layer has a moisture content of less than 10% by weight.
27. A method of producing a multilayered structure suitable as an electrode in a power source, comprising the steps of;
a. forming a first laminar structure by
providing a fuel layer containing a source of chemical energy comprising an essentially dry carbohydrate material,
b. forming a second laminar structure by
providing an enzyme layer containing an essentially dry enzyme capable of oxidizing or dehydrogenating the carbohydrate material, and
c. abutting the fuel layer of the first laminar structure with the enzyme layer of the second laminar structure in order to form said multilayered structure.