Electropolymerization groups

Oxidation of P-nicotinamide adenine dinucleotide (NADH) to NAD+ has attracted much interest from the viewpoint of its role in biosensors reactions. It has been reported that several quinone derivatives and polymerized redox dyes, such as phenoxazine and phenothiazine derivatives, possess catalytic activities for the oxidation of NADH and have been used for dehydrogenase biosensors development [1, 2]. Flavins (contain in chemical structure isoalloxazine ring) are the prosthetic groups responsible for NAD+/NADH conversion in the active sites of some dehydrogenase enzymes. Upon the electropolymerization of flavin derivatives, the effective catalysts of NAD+/NADH regeneration, which mimic the NADH-dehydrogenase activity, would be synthesized [3]. 

Vinyl substituted bipyridine complexes of ruthenium 9 and osmium 10 can be electropolymerized directly onto electrode surfaces The polymerization is initiated and controlled by stepping or cycling the electrode potential between positive and negative values and it is more successful when the number of vinyl groups in the complexes is increased, as in 77 A series of new vinyl substituted terpyridinyl ligands have recently been synthesized whose iron, cobalt and ruthenium complexes 72 are also susceptible to electropolymerization... 

The development of polypyrroles bearing supported diphosphine ligands protected from oxidation by borane groups has been reported.86 The polymer was produced by the electropolymerization of l-(7V-but-4-yl-pyrrol)-l,2-bis(diphenylphosphinoborane) (62) (Fig. 40). These preformed polymeric films lend themselves to the incorporation... 

Investigations of 5 with different R groups showed that fast grafting can be obtained for the most inert radicals, R = Aik (from Me to C18H37) and ethynyl, whereas for more reactive 12, e.g. Ar, side reactions were observed, in particular electropolymerization on the silicon surface. For example, such behavior was found for 5r and the first steps of the formation of a polymeric layer can be described by equations 23. 

Fig. 18.1. (A) Schematic presentation of the biotin-avidin complex with detailed configuration of biotin and surrounding polar residues. (B) Detailed (top) and simplified (bottom) representations of the complication possibilities of biotin and avidin. (C) Structure of an electropolymerizable biotin derivative and schematic presentation of an electropolymerized polypyrrole film bearing biotin groups on its surface. All three-dimensional representations of avidin have been generated using the program VMD [70] and subsequently rendered with PovRay.

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