Biochemically modified electrodes

Fig. 19. Basic types of biochemically modified electrodes. Symbols as in Fig. 18.

T. Sakata, S. Matsumoto, Y. Nakajima, and Y. Miyahara, Potential behaviour of biochemically modified gold electrode for extended-gate field-effect transistor. Jpn. J. Appl. Phys. 44, 2860-2863 (2005). 

Since the pioneering work of Lane and Hubbard, there have been numerous examples of using chemisorption to modify electrode surfaces. For example, Anson and his coworkers have investigated chemisorption of various aromatic systems onto carbon electrodes [12]. In this case, n-electron density is shared between the electrode and the adsorbate molecule. Examples of electroactive molecules that have been used to modify electrode surfaces via this approach are shown in Table 13.1 [8]. It is of interest to note that from the very beginning, there was considerable interest in modifying electrode surfaces with biochemical substances (Table 13.1). This is because such modified electrodes seemed to be likely candidates for use in electrocatalytic processes and biochemical sensors (see Section V). 

In the last decade, there has been a large number of reports on synthetic macro-molecule-metal complexes concerning their complexation, catalytic activities, redox reactions, adsorptions of gaseous molecules and metal ions, photochemical behavior, biochemical effects, modified electrodes, semiconductive and conductive materials, and so on. 

This review gives a brief summary of the "types of chemically modified electrodes, their fabrication, and some examples of their uses. One especially promising area of application is that of selective chemical analysis. In general, the approach used is to attach to the electrode surface electrochemically reactive molecules which have electrocatalytic activity toward specific substrates or analytes. In addition, the incorporation of biochemical systems should greatly extend the usefulness of these devices for analytical purposes. 

Due to high biocompability and large surface are of cobalt oxide nanoparticles it can be used for immobilization of other biomolecules. Flavin adenine FAD is a flavoprotein coenzyme that plays an important biological role in many oxidoreductase processes and biochemical reactions. The immobilized FAD onto different electrode surfaces provides a basis for fabrication of sensors, biosensors, enzymatic reactors and biomedical devices. The electrocatalytic oxidation of NADH on the surface of graphite electrode modified with immobilization of FAD was investigated [276], Recently we used cyclic voltammetry as simple technique for cobalt-oxide nanoparticles formation and immobilization flavin adenine dinucleotide (FAD) [277], Repeated cyclic voltammograms of GC/ CoOx nanoparticles modified electrode in buffer solution containing FAD is shown in Fig.37A. 

Mena, M.L.,Yanez-Sedeno, P., Pingarron, J.M. (2005) A comparison of different strategies for the construction of amperometric enzyme biosensors using gold nanoparticle-modified electrodes. Anal. Biochem., 336, 20-27... 

Electrochemical biosensor A self-contained integrated device that is capable of providing specific quantitative or semiquantitative analjrtical information using a biological recognition element (biochemical receptor), which is retained in direct spatial contact with an electrochemical transduction element [6]. A biosensor with an electrochemical transducer may represent a chemically modified electrode. 

Fig. 1 Chromatograms of a standard solution of monoamine transmitters and their metabolites at (A) a poly(para-aminobenzoic acid) modified electrode and (B) a bare glassy carbon electrode. (1) Norepinephrine, (2) epinephrine, (3) dopamine, (4) 3,4-dihydroxyphenol acetic acid, (5) serotonin, (6) 5-hydroxyindole acetic acid, and (7) homovanillic acid. Source From Study on the effect of electromagnetic impulse on neurotransmitter metabolism in nerve cells by high performance liquid chromatography-electrochemical detection coupled with microdialysis, in Anal. Biochem. ...

Because of their stability against chemical dissolution and their effective promotion of oxidations of biochemical compounds, catalysts comprising inorganic polymers and other maCTomolecules that contain platinum-group metal centers will be the focus of the present report. The applications primarily will be as amperometric detectors in HPLC and in flow-injection analysis, in which case both surface-modified electrodes and doped CCEs are suitable. Specifically addressed will be the use of sol-gel processing as a means of immobilizing catalysts in composites. 

Table 1 Analytical Figures-of-Merit for the Determination of Biochemical Compounds by Electrochemical Oxidation at Modified Electrodes Using Flow-Injection Methodology...

Hu, X., Dou, W., Fu, L. and Zhao, G. (2013) A disposable immunosensor for Enterobacter sakazakii based on an electrochemically reduced graphene oxide-modified electrode AnflZ. Biochem., 434,218-220. 

Liu, S.-Q. and H.-X. Ju. 2002. Renewable reagentless hydrogen peroxide sensor based on direct electron transfer of horseradish peroxidase immobilized on colloidal gold-modified electrode. Anal. Biochem. 307 110-116. 

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