Objetivo
THE ADVANTAGE OF USING ELECTRICITY IN COMBINATION WITH OXIDATION-REDUCTION ENZYMES IS THE LOW COSTS AND CLEAN FORM OF THIS POWER. A DIRECT ELECTRON TRANSFER BETWEEN AN ELECTRODE AND A REDOX ENZYME IS, HOWEVER, VERY INEFFICIENT. REDOX MEDIATORS OR CONDUCTING POLYMERS CAN HELP TO BRIDGE THIS TRANSFER. AFTER IMMOBILISATION, THESE REACTIONS CAN TAKE PLACE WITHOUT CONTAMINATING THE PRODUCTS WITH THE USUAL REDOX MEDIATORS AND AT THE SAME TIME THE PRODUCTS CAN BE EASILY SEPARATED. THESE SYSTEMS CAN THEREFORE BE USED FOR ELECTRO-ENZYMATIC, STEREOSPECIFIC REDUCTION REACTIONS AT A PREPARATIVE SCALE AND IN, FOR EXAMPLE, AMPEROMETRIC BIOSENSORS FOR ANALYTICAL PURPOSES.
The model of bioelectrochemical reactions calculates the current and concentration of species as a function of time for bioelectrochemical reactions at a flat electrode surface. In this model the mathematical equations describing chronoamperometric experiments are used without further approximation or simplification.
In order to apply redox biocatalysts in an economic way, electrodes of electrochemcial cells should be useful as a source or sink for electrons. However, enzymes are usually not able to exchange electrons directly with electrodes and need in general very expensive biological electron carriers, which are also not able to exchange electrons with electrodes.
Enzymes have been found which react with simple artificial and cheap electron carriers which can be oxidised or reduced on electrodes. The enzymes are enoate reductase (ER) and a viologen dependent nicotinamide adenine dinucleotide (phosphate) oxidoreductase (VAPOR). VAPOR enables the use of a large number of nicotinamide adenine dinucleotide (phosphate) dependent oxidoreductases for preparative scale synthesis via electrochemical mediator regeneration. Bifunctional mediators have been synthesized and their suitability as spacers and molecular wires has been tested. Enzyme kinetic parameters of ER, lipodehydrogenase and VAPOR with viologens and cobalt cage complexes and rate constants by electrochemical measurements have been determined. The new mediators were immobilized on carbon electrodes and enzymes were immobilized on the mediator carrying electrode. In order to optimize such systems, mathematical modelling was successfully developed.
Covalent coimmobilization of bifunctional mediators and enzyme (VAPOR) on carbon electrodes led to protein monolayers or multilayers doped with mediator molecules acting as electron relays and molecular wires between the electrode and the enzyme layer. These completely immobilized systems are the first in which electrons reach the active centre of the enzyme directly. This is different from the known case of mediated diffusion controlled homogenous catalysis. So far, these new systems produced up to 3.5 nmol h{-1} cm{-2} of reduced nicotinamide adenine dinucleotide. Immobilized on carbon felt (750 m{2} inner surface/m{2} macroscopic area) a current density of 1A m{-2} of m acroscopic area could be expected. Optimization of the systems is in progress. One of the main drawbacks is that the mediators either showed insufficient long term stability during the production process or that the long term stability was sufficient but the electron transfer rate from the mediator to the mediator to the enzyme was too low.
THE OBJECTIVE OF THIS PROJECT IS TO DRIVE, FOR PREPARATIVE PURPOSES, THE ENZYME CATALYSED ELECTROCHEMICAL REDUCTION OF ENOATES, 2-OXOCARBOXYLATES AND NAD(P)+, RESPECTIVELY, BY EITHER CORRESPONDING ENZYME-REDOX MEDIATOR MODIFIED ELECTRODES OR CORRESPONDING CONDUCTING POLYMER MODIFIED ELECTRODES. THE ENZYMES STUDIED WILL BE ENOATE- AND 2-OXOCARBOXYLATE REDUCTASE AS WELL AS THE VIOLOGEN DEPENDENT NAD(P) OXIDOREDUCTASE. THE RECOVERY AND STABILITY OF THESE ENZYMES WILL BE TESTED AFTER ENTRAPMENT IN CONDUCTING POLYMERS. THE IMMOBILISATION OF THE ENZYMES AT ELECTRODE SURFACES IN THE PRESENCE OF REDOX MEDIATORS WILL BE WORKED OUT BY THE MUENCHEN GROUP, AFTER WHICH THE DELFT GROUP WILL DO THE SCALING UP OF THIS SYSTEM. NEXT TO THIS ELECTROENZYMATIC CELLS WILL BE CONSTRUCTED WITH SPECIAL ATTENTION TO THE SOURCE OF CARBON AND THE DESIGN OF THE WORKING ELECTRODE. FINALLY THE MOST OPTIMAL COMBINATION, WAY OF IMMOBILISATION, SOURCE OF CARBON AND ELECTRODE DESIGN WILL BE TESTED AND THE FEASIBILITY OF THIS SYSTEM IN ORGANIC SOLVENTS STUDIED.
Ámbito científico (EuroSciVoc)
CORDIS clasifica los proyectos con EuroSciVoc, una taxonomía plurilingüe de ámbitos científicos, mediante un proceso semiautomático basado en técnicas de procesamiento del lenguaje natural. Véas: El vocabulario científico europeo..
CORDIS clasifica los proyectos con EuroSciVoc, una taxonomía plurilingüe de ámbitos científicos, mediante un proceso semiautomático basado en técnicas de procesamiento del lenguaje natural. Véas: El vocabulario científico europeo..
- ciencias naturales ciencias químicas química inorgánica metales de transición
- ciencias naturales ciencias químicas ciencia de polímeros
- ciencias naturales ciencias químicas catálisis biocatálisis
- ciencias naturales ciencias biológicas bioquímica biomoléculas proteínas enzima
- ciencias naturales matemáticas matemáticas aplicadas modelo matemático
Para utilizar esta función, debe iniciar sesión o registrarse
Programa(s)
Programas de financiación plurianuales que definen las prioridades de la UE en materia de investigación e innovación.
Programas de financiación plurianuales que definen las prioridades de la UE en materia de investigación e innovación.
Tema(s)
Las convocatorias de propuestas se dividen en temas. Un tema define una materia o área específica para la que los solicitantes pueden presentar propuestas. La descripción de un tema comprende su alcance específico y la repercusión prevista del proyecto financiado.
Datos no disponibles
Las convocatorias de propuestas se dividen en temas. Un tema define una materia o área específica para la que los solicitantes pueden presentar propuestas. La descripción de un tema comprende su alcance específico y la repercusión prevista del proyecto financiado.
Convocatoria de propuestas
Procedimiento para invitar a los solicitantes a presentar propuestas de proyectos con el objetivo de obtener financiación de la UE.
Datos no disponibles
Procedimiento para invitar a los solicitantes a presentar propuestas de proyectos con el objetivo de obtener financiación de la UE.
Régimen de financiación
Régimen de financiación (o «Tipo de acción») dentro de un programa con características comunes. Especifica: el alcance de lo que se financia; el porcentaje de reembolso; los criterios específicos de evaluación para optar a la financiación; y el uso de formas simplificadas de costes como los importes a tanto alzado.
Régimen de financiación (o «Tipo de acción») dentro de un programa con características comunes. Especifica: el alcance de lo que se financia; el porcentaje de reembolso; los criterios específicos de evaluación para optar a la financiación; y el uso de formas simplificadas de costes como los importes a tanto alzado.
Coordinador
2595 CL DEN HAAG
Países Bajos
Los costes totales en que ha incurrido esta organización para participar en el proyecto, incluidos los costes directos e indirectos. Este importe es un subconjunto del presupuesto total del proyecto.