Electroactive self-assembled monolayers, with

A number of important conclusions were drawn from this study, as follows. Electrochemical reversibility in electroactive self-assembled monolayers depends upon concentration and polarity of a covalently attached redox probe. Reversible surface electrochemistry is observed for the well-diluted ferrocenyl ester. However, reversibility decreases with steric congestion of redox probe because higher redox probe concentrations lead to disorder due to cross-sectional mismatch of the redox probe and the alkyl chain. Reversibility also decreases with a nonpolar redox probe the alkylferrocene (System 4) yields broad peaks with long tails positive of E°, consistent with kinetic dispersion of the redox probes and their differential solvation in the SAM. 

Cell Adhesion and Detachment, Figure 4 A self-assembled monolayer with an electroactive functional group bound to the RGD peptide. This quinine group is converted into a lactone group upon the application of an electrical potential and this change releases the RGD group from the surface. Taken from [3]... 

Very recently Lahav et al. [116] used a photochemically cleavable template to introduce gate sites into an alkanethiol self-assembled monolayer on a gold electrode. The electrode showed an enhanced amperometric response to the electroactive template, compared with an electrode with a monolayer without gate sites. 

Eor heterogeneous electron transfer, the use of ordered organic monolayers (self-assembled monolayers or SAMs) at electrode surfaces as blocking films either with electroactive species in the electrolyte [26] or with electroactive groups tethered at the opposite end of the blocking molecule from the covalent attachment end [27] has provided a method to study the effect of electrode-redox center distance and the effect of the electrode potential on the electron-transfer rate. 

R.-K. Lo, J. E. Ritchie, J.-P. Zhou, J. Zhao, and J. T. McDevitt, Polypyrrole growth on YBa2Cu30 -s modified with a self-assembled monolayer of 7V-(3-aminopropyl)pyrrole Hardwiring the electroactive hot spots on a superconductor electrode, J. Am. Chem. Soc. 118 11295 (1996). 

If a self-assembled monolayer (SAM) contains an electroactive group, M, the regeneration of the mediator can occur via a bimolecular reaction with these surface-bound redox centers (Figure 5.7A) ... 

Other common techniques have been applied to the assembly of layers or films of TTF-derived molecular conductors. Compound 29 is an example of an amphiphilic TTF derivative. It forms conducting Langmuir-Blodgett charge transfer films with the acceptor TCNQF4 (30).98 Self-assembly of compound 31 on gold by electrochemical methods yielded an electroactive monolayer which was remarkably stable to electrochemical cycling.99... 

Figure 7.1 Representative examples of electroactive compounds with pendant thiol groups able to self-assemble into monolayers on the surface of gold electrodes.

Cell Adhesion and Detachment, Fig. 5 Release of cells from a surface coated with self-assembled mono-layers coupled to the RGD peptide. The left side of the surface has a monolayer that is not electroactive, and the right side of the surface has a monolayer that contains the electroactive quinone group. Fibroblast cells initially adhere on both sides of the surface (a). Upon the application of an electrical potential, the quinone groups are converted to lactone groups and release the RGD groups along with the cells attached to these groups (b) (Taken from Yeo et al. [3])... 

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