Poly ferrocene-modified

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. 

PVP-Os Osmium-bipyridyl-modified quaternized poly 4-vinylpyridine) [102,206,207] PAH-Fc Ferrocene-modified polyallylamine [77, 101, 208] P(CM-FcJ Poly(vynil ferrocene) copolymer [224] PVn Polyalkylviologens (PVn, n number of methylene groups) [67, 104,... 

Synthesis of Ferrocene-Modified Poly(ethyl glutamate) 105 6X ... 

Poly(", -ethyl L-glutamate) (0.10 g), prepared by the polymerization of the corresponding NCA, was allowed to swell in DMA (0.8 mL) and ferrocenylmethylamine 104 (0.2 g) was added. The viscous orange soln was heated to 75 °C for 18 h, then cooled, and diluted with EtOH (5mL) and Et20 (20 mL). The ferrocene-modified polypeptide 105 (0.10 g) formed a dark orange solid characterized by elemental analysis, which gave 6.0% of iron IR (KBr) vCq 1725, 1640,1530 cm-1. 

Figure 4. (left) Steady state response to 31.5 mM glucose of the ferrocene-modified poly(siloxane) / glucose oxidase / carbon paste electrodes at several applied potentials. The relay systems are indicated next to each curve, which is the mean result for four electrodes. 

Figure 8. (right) Glucose calibration curves for the ferrocene-modified poly(ethylene oxide)/glucose oxidase/carbon paste electrodes at E =... 

Karan et al. [10] reported glucose sensors using quinone modified poly-siloxane (Fig. 3.8a-A) and acrylonitrile-ethylene (Fig. 3.8a-B) co-polymers and glucose oxidase. Sensors constructed with glucose oxidase and quinone modified polysiloxane were considerably more efficient than those using acrylonitrile-ethylene system to transfer electrons from reduced glucose oxidase to a conventional carbon paste electrode. Their results coincide with those described previously for the ferrocene-modified polysiloxane system. The excellent flexibility of poly(siloxane) allows it to function as an efficient... 

Niwa M, Matsui M, Koide K, Higashi N. Enantioselective adsorption of ferrocene-modified glutamic acids on helical poly(L-glutamic acid) self-assemblies at gold electrodes. J Mater Chem 1997 7 2191-2192. 

Earlandite structure, 849 Electrical conductivity metal complexes, 133 tetracyanoplatinates anion-deficient salts, 136 Electrical properties metal complexes, 133-154 Electrocatalysis, 28 Electrochemical cells, 1 Electrochemistry, 1-33 hydrogen or oxygen production from water coordination complex catalysts, 532 mineral processing, 831 reduction, 831 Electrodeposi (ion of metals, 1-15 mineral processing difficulty, 831 Electrodes clay modified, 23 ferrocene modified, 20 nation coated, 15 polymers on, 16 polyvinylferrocene coated, 19 poly(4-vinylpyridine) coated, 17 redox centres, 17 Prussian blue modified, 21 surface modified, 15-31 Electrolysis... 

In some cases the polymer incorporates the mediator, producing a redox macromolecule, e.g., poly[(ferrocenyl)amidopropyl]pyrrole, ferrocene-modified poly(ethylene oxide), " and highly flexible ferrocene-modified silox-ane. These redox polymers have short chains and low molecular weights (< 20 kDa) they function as a special kind of diffusional mediators and do not alleviate the loss of a mediator to the bulk solution during amperometric detection. 

In this paper, the development and characterization of a poly(anilinomethyl-ferrocene) modified glassy carbon electrode for determination of hydrogen peroxide by reduction at low applied potential is reported. 

S. J. Higgins, L. J. Christopher and S. M. Francis, Synthesis and electropolymerization of l,l -bis(5-oligothienyl)ferrocenes poly(oligothiophene—ferrocene)-modified electrodes, Synth. Met., 98, 211-214 (1999). 

The concept of a redox-modified hydrogel has also been successfully expanded to covalently immobilized ferrocene onto linear poly-(ethyl-enimine) (LPEI)." Ferrocene-modified LPEI has been shown to effectively mediate electron transfer for a wide range of enzymes including glucose oxidase, fructose dehydrogenase, and horseradish peroxidase to produce current densities as high as 13... 

Another approach is based on the application of redox polders, e.g. osmium complex-modified poly(vinyl pyridine) (9-11) or ferrocene-modified poly(siloxanes) (12,13X crosslinked together with an enzyme on the top of the electrode. The electron transfer fi-om the active site of the polymer-entrapped enzyme to the electrode surfece occurs to a first polymer-bound mediator which has suflSdently approached the prosthetic group to attain a fast rate constant for the electron-tranrfer reaction. From this first mediator the redox equivalents are transported along the polymer chains by means of electron hopping between adjacent polymer-linked mediator molecules (Fig. 2). Extremely fast amperometric enzyme electrodes have been obtained with si ificantly decreased dependence fi-om the oxygen partial pressure. However, die redox polymer/enzyme/crosslinker mbcture has to applied either manually or by dipcoating procedures onto the electrode surface. 

One of the first CPs to be studied as a modified electrode was P(Py), at which the electrochemistry of ferrocene (FeCp2) was studied [55]. This FeCp2 system (E° +0.42 V vs. SCE) showed near ideal reversible electrochemical behavior, with proportional to indicating diffusion limited processes, cathodic/anodic peak current ratios of near unity, and cathodic/anodic peak separations close to 70 mV. More recently, poly (bithiophene) modified electrodes have been used to monitor the electrochemistry of FeCp2 as well as / -benzoquinone, and to probe the semiconducting behavior of this CP [56]. Ferrocene appears popular as a near-reversible probe material for CP-modified electrodes, having been studied with poly(thiophene) and other CP modified electrodes as well [57]. 

Fig. 35 Electromechanical impedance of ferrocene-modified poly(N-isopropyl acrylamide) gels in response to variations in electrode potential (reprinted with permission from [350]. Copyright...

Thin hydrogel films made of ferrocene-modified poly(ethylene imine) with embedded enzymes can act as biosensors for glucose [600, 601]. Similarly, other glucose-dependent biosensors have been constructed [602-604] e.g., a poly (vinylferrocene)-enzyme composite deposited on an electrode acted as a mediator for glucose oxidation [605-610]. Immunosensors were realized on glassy carbon electrodes by ferrocene-dendrimer-modified antibodies, which quench electrochemiluminescence [611]. 

Zhu L, Shangguan Y, Sun Y, Ji J, Zheng Q (2010) Rheological properties of redox-responsive, associative ferrocene-modified branched poly(ethylene imine) and its modulation by beta-cyclodextrin and hydrogen peroxide. Soft Matter 6 5541-5546... 

Meredith MT, Hickey DP, Redemann JP, Schmidtke DW, Glatzhofer DT (2013) Effects of ferrocene methylation on ferrocene-modified linear poly(ethylenimine) bioanodes. Electrochim Acta 92 226-235... 

Fig. 7. Horse-liver alcohol dehydrogenase (HLADH) catalyzed alcohol oxidation at a graphite felt anode modified by poly(acrylic acid) (PAA) under coimmobilization of ferrocene derivatives (Fc), diaphorase (Dp), and HLADH [39]...

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