Polymer-film-modified electrodes

Figure 4.29 Scattering length density profiles for an [Os(bpy)2(PVP)ioCl]Cl film in (a) perchloric acid, and (b) p-toluene sulfonic acid at different pff levels. From R.W. Wilson, R. Cubitt, A. Glidle, A.R. ffillman, P.M. Saville and J.G. Vos, A neutron reflectivity study of [Os(bpy)2(PVP)ioCl]+ polymer film modified electrodes effect of pff and counterion, /. Electrochem. Soc., 145,1454-1461 (1998). Reproduced by permission of The Electrochemical Society, Inc...

Polymer-film modified electrodes are used for a variety of applications, such as electrocatalysis (5-8). analysis (9.10). and more recently for their permselectivity characteristics (11-1H). These polymer films are formed by casting the film on an electrode surface (12), using radio-frequency plasma (15), or by electropolymerization (13.16.17). Alternatively, a polymer film 1s formed as a discrete membrane Eind subsequently applied to an electrode (18). The use of both cast and discrete membrane films... 

Revin SB, John SA. Selective and sensitive electrochemical sensor for 1-methionine at physiological ph using functionalized triazole polymer film modified electrode. Electroanalysis 2012 24(6) 1277-83. 

D Souza, R, Y.-Ying Hsieh, H. Wickman, and W. Kutner (1997). /S-cyclodexttin and carboxymethylated /S-cyclodextrin polymer film modified electrodes, hosting cobalt porphyrins, as sensors for electrocatalytic determination of oxygen dissolved in solution. Electroanalysis 9(14), 1093-1101. 

Kutner W, Dobihofer K (1992) Simultaneous cyclic voltammetry and electrochemical quartz-crystal microbalance study at polymer film-modified electrodes of molecular inclusion of ferrocene by p-cyclodextrin polymer and carboxymethylated p-cyclodextrin polymer as well as ferrocenecarboxylic acid by p-cyclodextrin polymer. J Electroanal Chem 326 139-160... 

Therefore, recent interest has been focused prevailingly on electrodes modified by a multilayer coverage, which can easily be achieved by using polymer films on electrodes. In this case, the mediated electron transfer to solution species can proceed inside the whole film (which actually behaves as a system with a homogeneous catalyst), and the necessary turnover rate is relatively lower than in a monolayer. 

Considerable potential exists to design surface modified electrodes which can mimic the behaviour of electronic components. For example, a rectifying interface can be produced by using two-layer polymer films on electrodes. The electroactive species in the layers have different redox potentials. Thus electron transfer between the electrode (e.g. platinum) and the outer electroactive layer is forced to occur catalytically by electron transfer mediation through the inner electroactive layer. 

J. G. Gaudiello, P. K. Gosh, and A. J. Bard, Polymer films on electrodes. 17. The application of simultaneous electrochemical and electron spin resonance techniques for the study of two viologen-based chemically modified electrodes, J. Am. Chem. Soc. 107, 3027-3032 (1985). 

Conducting polymer films (modified or not) have been also used to perform the oxidation of organic compounds, such as ascorbic acid. For example, the rate of the electro-oxidation of ascorbic acid on glassy carbon is increased when the carbon electrode is previously covered with a polypyrrole layer [164]. In... 

GabrieUi, C., O. Haas, and H. Takenoutti, Impedance analysis of electrodes modified with a reversible redox polymer film. Journal of Applied Electrochemistry, 1987. 17 p. 82 GabrieUi, C., H. Takenoutti, O. Haas, and A. Tsukada, Impedance investigation of the charge transport in film-modified electrodes. Journal of Electroanalytical Chemistry, 1991. 302 pp. 59-89... 

The redox polymers, both of organic and inorganic origin (such as polyvinylpyridine modified by redox-active complexes of metals Prussian blue and related materials), can be considered as a version of electrodes of the second kind however, the equilibrium is usually estabhshed with respect to cations. Electron conducting polymers (polyanyline, polypyrrol, and so forth) also pertain, in the first approximation, to the electrodes of the second kind, which maintain equilibrium with respect to anion. Ion exchange polymer films on electrode surfaces form a subgroup of membrane electrodes. 

Yousef, U.S. Electrooxidative polymerization of 3-[l-(2-amino-[henylimino)-ethyl]-6-methylpyran-2,4-dione Schiff base in acetonitrile and redox properties of the resulting platinum-film modified electrodes. Eur. Polym. J. 35, 133-143. 

This Volume describes, how to prepare monolayer modified electrodes on metals, carbons, silicon, conducting metal oxides, and chalcogenides how to prepare film modified electrodes including polymer... 

Conductive polymer films on electrodes have been prepared by electrochemical polymerization of electroactive monomers such as a pyrrole-substituted mediator, or by evaporating solutions containing preformed polymer. Examples of electrocatalyses reported include the oxidation of alcohols by pyrrole-substituted 2,2,5,5-tetramethyl-3-pyrroline-l-oxyl [26] and organohalide de-halogenation by pyrrole-substituted 4,4 -bipyridinium salt [27]. The preparation of mediator-modified electrode by evaporating solutions of preformed polymers was carried out by dip-coating polymers including mediators on electrode surface or by covalent attachment of mediators to dip-coated polymers on electrode surfaces. Examples of the former electrocatalyses are selected from the several reports on the oxidation of NADH by dopamine... 

This review covers investigations of ICPs either prepared elec-trochemically or modified/investigated with electrochemical methods. With a few exceptions, most polymers prepared by electropolymerization are also studied with electrochemical methods. This is most likely due to the fact that electropolymerization results preferably in films that adhere to the electrode surface used as a substrate during polymerization. These samples—essentially polymer-coated modified electrodes— lend themselves to further investigations with said methods. On the contrary, chemical oxidation results preferably in powdery samples that are less suitable for electrochemical investigations. The experimental studies of these polymers make use of almost all kinds of electrochemical methods currently available. Unfortunately—and this has been known to electrochemists for a few decades— purely electrochemical methods provide only a rather general or macroscopic picture of the interface between electrolyte solutions and electrodes or of the species (films, adsorbates, etc.) present on the electrode sur-... 

Brahman, P.K., et al., Voltammetric determination of anticancer drug flutamide in surfactant media at polymer film modified carbon paste electrode. Colloids Surf., A, 2012. 396 p. 8-15. 

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