Monolayer immobilized

Fig. 2.7 Set-up of permeation experiment through organosilane monolayer immobilized on a porous glass plate. Reprinted with permission from [46], K. Ariga and Y. Okahata,J. Am. Chem. Soc., 1989, 77 7, 5618. 1989, American Chemical Society.

Already mentioned was a complete cell reported by Katz et al. based on monolayer immobilization of mediator and biocatalyst at both anode and cathode (Figure 7). Operating in 1 mM glucose and air-saturated buffer at pH 7 and 25 °C, the cell generated a maximum current density of 110 juAlcrn at 0.04 V cell potential, corresponding to a maximum power of... 

B. Limoges, J.-M. Saveant and D. Yazidi, Quantitative analysis of catalysis and inhibition at horseradish peroxidase monolayers immobilized on an electrode surface, J. Am. Chem. Soc., 125 (2003) 9192-9203. 

Surface redox reactions — or surface -> electrode reactions, are reactions in which both components of the -> redox couple are immobilized on the electrode surface in a form of a -> monolayer. Immobilization can be achieved by means of irreversible -> adsorption, covalent bonding, self-assembling (- self-assembled mono-layers), adhesion, by Langmuir-Blodgett technique (- Langmuir-Blodgett films), etc. [i]. In some cases, the electrode surface is the electroactive reactant as well as the product of the electrode reaction is immobilized on the electrode surface, e.g., oxidation of a gold, platinum, or aluminum electrode to form metal oxide. This type of electrode processes can be also considered as surface electrode reactions. Voltammetric response of a surface redox reaction differs markedly from that of a dissolved... 

Katz, E, Lion-Dagan, M., and Willner, I. Control of electrochemical processes by photo-isomerizable spiropyran monolayers immobilized onto Au-electrodes Amperometric transduction of optical signals. J. Electroanal. Chem. 1995, 382,25-31. 

A theoretical understanding of the mechanism of mediation is important in the design of catalytic CMEs [12], Eor example, it is known that the mechanisms of monolayer immobilized mediator, as shown in Fig. 1(a), proceeds in two steps. 

The molecular aggregation state in the NTS monolayer was investigated by XR measurement. Figure 3 shows the XR and the fitting curves for the NTS monolayer immobilized onto the silicon wafer substrate at a surface pressure of 15 mN m l at 293... 

Chiral Monolayer-immobilized Electron-transfer Mediators... 

The presence of a surfactant also affects the hydrodynamic interactions between fluid particles in dispersions. When the surfactant is soluble in the continuous phase, the adsorption monolayers immobilize the drop (bubble) surfaces and decelerate the approach of two such particles. On the contrary, if the surfactant is dissolved in the droplets (in the disperse phase), it efficiently damps the surface tension gradients and accelerates the approach and (eventually) coalescence of the droplets. The processes of surfactant transfer from the continuous toward the disperse phase, or vice versa, also influence the droplet-droplet hydrodynamic interactions see Sec. Vn. 

A large number of potential applications for organized protein monolayers have recently motivated considerable research activity in this field (Boussaad et al. 1998, Kiselyova et al. 1999). Construction of specific interaction-directed, self-assembled protein films has been performed at the air-water interface. The Langmuir-Blodgett (LB) technique has been extensively used to order and immobilize natural proteins on solid surfaces (Tronin et... 

In this chapter we describe the basic principles involved in the controlled production and modification of two-dimensional protein crystals. These are synthesized in nature as the outermost cell surface layer (S-layer) of prokaryotic organisms and have been successfully applied as basic building blocks in a biomolecular construction kit. Most importantly, the constituent subunits of the S-layer lattices have the capability to recrystallize into iso-porous closed monolayers in suspension, at liquid-surface interfaces, on lipid films, on liposomes, and on solid supports (e.g., silicon wafers, metals, and polymers). The self-assembled monomolecular lattices have been utilized for the immobilization of functional biomolecules in an ordered fashion and for their controlled confinement in defined areas of nanometer dimension. Thus, S-layers fulfill key requirements for the development of new supramolecular materials and enable the design of a broad spectrum of nanoscale devices, as required in molecular nanotechnology, nanobiotechnology, and biomimetics [1-3]. 

Two-dimensional protein layer orientation could be also effected by metal-ion coordination Monolayer of iminodiacetate-Cu(II) lipid was successfully employed as substrate for oriented immobilization of proteins naturally displaying histidine residues on their surface [37]. Affmity-resin-displaying Ni(II) complexes could also be successfully employed for oriented protein immobilization [38]. 

Patterning of enzyme monolayers on a solid surface was carried out by photoactivation of immobilized monolayer of caged -biotin derivatives in selected areas. Specific oriented binding of enzyme-avidin conjugates could be readily made to the photoactivated zones [42]. Oriented immobilization of G-protein-coupled receptors on a solid surface was also made possible on a biotinylated surface by first immobilizing streptavidin, followed by the immobilization of biotinylated G-protein-coupled receptor [43]. 

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