New methods of immobilization of oxidases at electrodes

Renata Bilewicz ,  Ewa Nazaruk ,  Kazimierz Chmurski ,  Jerzy Rogalski ,  Maciej Klis 

Warsaw University, Faculty of Chemistry, Pasteura 1, Warszawa 02-093, Poland

Abstract

Retaining enzymes in functionally-active forms on the electrode surface is a challenging and difficult task. Ideally, the immobilization of protein should be performed under conditions that provide membrane like environment in which all the normal interactions of the proteins are preserved. Providing electronic contact of the protein molecules with the conducting substrate by means of a biocompatible medium is even more difficult. In the present talk several ways of contacting oxidases with electrodes will be discussed.Three step sequential self-assembly procedure was applied to prepare gold electrodes functionalized in a stable and controlled way with a β-cyclodextrin (β-CD). When thiolated cyclodextrins are used as active sites in the organothiol monolayers modifying electrodes, the electron transfer from solution species to the electrode is facilitated in the presence of appropriate mediators in the cyclodextrin cavity. Methylene blue in the cavities provided electrical contact between the electrode and solution resident enzyme - laccase catalyzing reduction of oxygen to water. Covalent binding of laccase to thiol monolayers using 11-mercaptoundecanoic acid as the organic junction was found to provide direct electrical contact with the enzyme together with its stable immobilization at the electrode. Direct electrochemistry of the enzyme can be observed and its catalytic activity demonstrated. Immobilization in thin films of lyotropic liquid crystal - lipidic matrix with cubic symmetry is discussed as a way of immobilizing enzymes by means of hydrophobic-hydrophilic interactions with lipid molecules. The electrochemical behaviour and method of immobilizing the fungal laccases in diamond type monoolein cubic phase will be discussed. The cubic phase prevents the enzymes from denaturation on the electrode surface, and provides contact of enzyme with the electrode. Thin layer of the cubic phase embedding glucose and pyranose oxidase activated glucose oxidation. The potentials and ratio of catalytic to diffusion currents are modified by choosing the appropriate electroactive probes as mediators. Ferrocenecarboxylic acid and Ru(NH3)62+ provided good contact between the electrode and the enzyme. The system based on Ru(NH3)62+ was found most suitable in terms of catalytic efficiency, low potential.

Acknowledgement: This work was financially supported by Ministry of Scientific Research and Information Technology - Project No. PBZ 18-KBN-098/T09/2003.

 

Related papers
  1. Recent developments in enzymatic biofuel cells
  2. Biofuel cell based on carbon nanotubes with covalently bonded laccase and glucose dehydrogenase embedded in cubic phase
  3. Tetraazamacrocyclic copper(II) and nickel(II) complexes in host - guest systems.
  4. Free-radical adsorption as a method of binding gold nanoparticles to gold electrode surfaces.
  5. Biofuel cell based on arylated carbon nanotubes
  6. Carbon nanotube nanostructured electrodes for membrane – less biofuel cell based on liquid-crystalline phases as matrices for enzymes
  7. Cyclodextrins as molecular recognition elements in monolayers
  8. A facile preparation of the nanoparticulate film from conductive and nonconductive particles of the opposite charge
  9. Poly-o-aminophenol as laccase mediator and influence of enzyme on the polymer electrodeposition
  10. Bioelectrocatalytic dioxygen reduction at carbon nanotubes – silicate composite film modified electrode
  11. A glucose/O2 biofuel cell based on electrodes modified with liquid-crystalline cubic phases
  12. Redox processes of dithiolated tetraazamacrocyclic complexes of Ni(II) and Cu(II) in solution and immobilized on gold electrodes
  13. Immobilization of molecules: From self-assembled monolayers to polymeric hollow structures
  14. Scanning electrochemical microscopy study of laccase embedded in sol-gel processed silicate film
  15. Nanostructured Carbon Electrodes For Oxygen Reduction Catalyzed By Laccase Without any Mediators
  16. Optimization of culture medium for laccase production by Trametes versicolor
  17. ß-Glucosidases from white rot fungus Phlebia radiata - purification and properties.
  18. Molecular Motions in New Catenanes
  19. Electron transport through alkanethiolate films decorated with monolayer-protected gold clusters
  20. Fine-tuning of properties of bismacrocyclic dinuclear cyclidene receptors by N-methylation.
  21. Designing of cathodes modified with enzymes for the biofuel cell applications
  22. Lipidic cubic phase for immobilising enzymes on electrodes
  23. Properties of monolayers of azocrown ethers: Ph -tunable equilibria for compounds with substituents containing mobile protons
  24. Electrocatalytic reduction of dioxygen by redox mediator and laccase immobilised in silicate thin film
  25. Modified Electrodes Based on Lipidic Cubic Phases

Presentation: Tutorial lecture at SMCBS'2005 Workshop, by Renata Bilewicz
See On-line Journal of SMCBS'2005 Workshop

Submitted: 2005-09-19 17:34
Revised:   2009-06-07 00:44