Bioelectrochemistry development

This chapter is intended to provide a selective overview of the most recent developments in EFC research. Several excellent and comprehensive reviews focused on aspects of EFC research have appeared over the past few years [7, 10-16]. We focus here on developments that may lead to deployment of an implantable glucose-oxidizing, oxygen-reducing EFC, as an example of the extensive research on EFC bioelectrochemistry. Developments, focused on using other fuels, such as hydrogen, alcohols, or other sugars, or oxidants will not be considered in detail. 

Armstrong F A and Wilson G S 2000 Recent developments in faradaic bioelectrochemistry Electrochim. Acta 45 2623... 

Cases are known where the external potentials attain high values. Even in antiquity, incomprehensible features of certain fishes were noted. Around 1800 it became clear that these features are associated with electric phenomena, and they were attributed to so-called animal electricity. It was in 1832, finally, that Faraday could show that the various types of electricity, including the animal variety, are identical in nature. Studies of the electric fishes performed in the first half of the nineteenth century had a notable effect on the development of bioelectrochemistry. 

Y.H. Wu and S.S. Hu, Direct electrochemistry of glucose oxidase in a colloid Au-dihexadecylphos-phate composite film and its application to develop a glucose biosensor. Bioelectrochemistry. Available online 6 May (2006). 

Figure 4.39 Schematic representations of the various types of electrode surfaces for which protein voltammetry is commonly observed (a) a metal electrode modified with an XY SAM (b) a metal oxide electrode (c) an electrode modified with a surfactant layer in which protein molecules are embedded (d) a pyrolitic graphite edge electrode, often used in conjunction with mobile co-adsorbates such as aminocyclitols. Reprinted from Uectrochim. Acta, 45, F.A. Armstrong and G.S. Wilson, Recent developments in faradaic bioelectrochemistry, 2623-2645, Copyright (2000), with permission from Elsevier Science...

The main purpose of this contribution, however, is to review recent advances in solid state ionics achieved by means of microelectrodes, i.e. electrodes whose size is in the micrometer range (typically 1-250 pm). In liquid electrolytes (ultra)-microelectrodes are rather common and applied for several reasons they exhibit a very fast response in voltametric studies, facilitate the investigation of fast charge transfer reactions and strongly reduce the importance of ohmic drops in the electrolyte, thus allowing e.g. measurements in low-conductive electrolytes [33, 34], Microelectrodes are also employed to localize reactions on electrodes and to scan electrochemical properties of electrode surfaces (scanning electrochemical microscope [35, 36]) further developments refer to arrays of microelectrodes, e.g. for (partly spatially resolved) electroanalysis [37-39], applications in bioelectrochemistry and medicine [40, 41] or spatially resolved pH measurements [42], Reviews on these and other applications of microelectrodes are, for example, given in Ref. [33, 34, 43-47],... 

In this chapter the intention is to give a view of present developments and research in bioelectrochemistry. It is not possible to describe the electrochemical aspects of all the kinds of biological events and processes occurring in living systems, but some examples will be presented and discussed to give an idea of the extent of bioelectrochemistry. 

Mannelli F, Minunni A, Tombelli S, Wang RH, Spiriti MM, Mascini M (2005) Direct immobilisation of DNA probes for the development of affinity biosensors. Bioelectrochemistry 66 129-138... 

There is a trend toward chiral synthesis [132] the Englehard company is said to have piloted the electrosynthesis of chiral diols. New reactor design for the epoxidation of olefins is under development on a pilot scale [133]. Gas diffusion electrodes, developed for fuel cells and inorganic processes, are finding their first applications in organic electrosynthesis [134—136]. Another area of more than laboratory interest is bioelectrochemistry [137] (see also E. Steckhan, Chapter 27 in this volume). 

The direct electrochemistry of redox proteins has developed significantly in the past few years. Conditions now exist that permit the electrochemistry of all the proteins to be expressed at a range of electrodes, and important information about thermodynamic and kinetic properties of these proteins can be obtained. More recently, direct electron transfer between redox enzymes and electrodes has been achieved due to the more careful control of electrode surfaces. The need for biocompatible surfaces in bioelectrochemistry has stimulated the development of electrode surface engineering techniques, and protein electrochemistry has been reported at conducting polymer electrodes 82) and in membranes 83, 84). Furthermore, combination of direct protein electrochemistry with spectroscopic methods may offer 85) a novel way of investigating structure-function relationships in electron transport proteins. 

Horozova, E., Dodevska, T., and Dimcheva, N. (2009) Modified graphites application to the development of enzyme-based amperometric biosensors. Bioelectrochemistry, 74 (2), 260-264. 

Armstrong, F.A., and Wilson, G.S. 2000. Recent developments in faradaic bioelectrochemistry. Electrochimica Acta 45, 2623-2645. 

There is much else in bioelectrochemistry apart from these modern developments in particular, there is the vast area associated with the names of Hodgkin and Huxley and the subject of electrophysiology, seen as an application of the Nernst-Planck equation. 

In Chapter 9, Bartlett and Cooper discuss the applications of electroactive polymers in bioelectrochemistry and bioelectronics. This is a very exciting and rapidly developing field, and it is proper that the volume includes this topic. Electroactive polymer materials will feature strongly in future developments in this area. Again Bartlett and Cooper have made major contributions in this field. 

The first three parts approach the classic aspects of electrochemistry on a BA/master s degree level. The fourth part touches on cutting-edge developments in the field of modern research (electrochemistry of solids, conducting polymers, physical methods for analysis, electrocatalysis, photoelectrochemistry, bioelectrochemistry, electrokinetics, interfaces between immisicible liquids, numerical simulations and nanoelectrochemistry, etc.)... 

Palecek E, Fojta M, and Jelen F (2002) New approaches in the development of DNA sensors. Hybridization and electrochemical detection of DNA and RNA at two different surfaces. Bioelectrochemistry 56 85-90. 

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