Polypyrrole bound

Polymerization of various monomers was performed with the ligands examined to synthesize a variety of polymeric ligands. The polypyrrole-bound mono- and bisphosphines 73 and 74 were prepared as their P-borane com-... 

Functionalized conducting monomers can be deposited on electrode surfaces aiming for covalent attachment or entrapment of sensor components. Electrically conductive polymers (qv), eg, polypyrrole, polyaniline [25233-30-17, and polythiophene/23 2JJ-J4-j5y, can be formed at the anode by electrochemical polymerization. For integration of bioselective compounds or redox polymers into conductive polymers, functionalization of conductive polymer films, whether before or after polymerization, is essential. In Figure 7, a schematic representation of an amperomethc biosensor where the enzyme is covalendy bound to a functionalized conductive polymer, eg, P-amino (polypyrrole) or poly[A/-(4-aminophenyl)-2,2 -dithienyl]pyrrole, is shown. Entrapment of ferrocene-modified GOD within polypyrrole is shown in Figure 7. 

The Teixidor team further improved upon this chemistry by covalently linking units of 109 to the polypyrrole monomer prior to electropolymerization.139 A [3,3 -Co(C2B<)H11)2] anion was covalently bound to a pyrrole via a spacer through one of its boron atoms by the reaction of the species [3,3 -Co(8-C4H802-l,2-C2B9H10)(r,2 -(C2B9H11)2] with potassium pyrrole, as functionalization through... 

Polypyrrole Molecular Interface for Electron Transfer of Electrode-bound Enzymes... 

The polypyrrole molecular interface has been electrochemically synthesized between the self-assembled protein molecules and the electrode surface for facilitating the enzyme with electron transfer to the electrode. Figure 9 illustrates the schematic procedure of the electrochemical preparation of the polypyrrole molecular interface. The electrode-bound protein monolayer is transferred in an electrolyte solution containing pyrrole. The electrode potential is controlled at a potential with a potentiostat to initiate the oxidative polymerization of pyrrole. The electrochemical polymerization should be interrupted before the protein monolayer is fully covered by the polypyrrole layer. A postulated electron transfer through the polypyrrole molecular interface is schematically presented in Fig. 10. 

Electrochemical communication between electrode-bound enzyme and an electrode was confirmed by such electrochemical characterizations as differential pulse voltammetxy. As shown in Fig. 11, reversible electron transfer of molecularly interfaced FDH was confirmed by differential pulse voltammetry. The electrochemical characteristics of the polypyrrole interfaced FDH electrode were compared with those of the FDH electrode. The important difference between the electrochemical activities of these two electrodes is as follows by the employment of a conductive PP interface, the redox potential of FDH shifted slightly as compared to the redox potential of PQQ, which prosthetic group of FDH and the electrode shuttling between the prosthetic group of FDH and the electrode through the PP interface. In addition, the anodic and cathodic peak shapes and peak currents of PP/FDH/Pt electrode were identical, which suggests reversibility of the electron transport process. 

Cyclic voltammetry was performed with the ADH-NAD-MB/polypyrrole electrode in 0.1 M phosphate buffer (pH 8.5) at a scan rate of 5 mV s l. The corresponding substrate of ADH caused the anodic current at +0.35 V vs. Ag/AgCl to increase. These results suggest a possible electron transfer from membrane-bound ADH to the electrode through membrane-bound NAD and MB with the help of the conductive polymer of polypyrrole. 

PPy-films doped with either NaOTs or polymer (1), they appear to be quite similar. Both show the typical absorbance profile of polypyrrole. The latter also shows two characteristic bands of the flavin units bound to polymer (1) (XtallUK==438 and 335 nm). 

Schuhmann, W., Zimmermann, H., Habermtiller, K., and Laurinavicius, V. (2000) Electron-transfer pathways between redox enzymes and electrode surfaces reagentless biosensors based on thiol-monolayer-bound and polypyrrole-entrapped enzymes. Faraday Discussions, 116, 245-255. 

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