Electrochemistry of Ferrocenyl Dendrimer−β-Cyclodextrin Assemblies at the Interface of an Aqueous Solution and a Molecular Printboard

Abstract

Water-soluble supramolecular assemblies of redox-active ferrocenyl-decorated (Fc) poly(propylene imine) (PPI) dendrimers and β-cyclodextrin (βCD) were adsorbed at self-assembled monolayers (SAMs) of βCD ("molecular printboards"). The dendrimers form a stable monolayer at the βCD SAM owing to multivalent host-guest interactions. In the present study, dendrimers of generation 1 (4 Fc end groups) up to generation 5 (64 Fc end groups) were investigated. The immobilization of the dendrimers at the βCD SAM can be under electrochemical control since Fc forms stable inclusion complexes with βCD, whereas the oxidized ferrocenium (Fc + ) does not. The redox-dependent adsorption process was studied by potential-dependent electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Detailed information was obtained on the adsorption and desorption kinetics, the diffusion constants, and the conformation of the guest dendrimers adsorbed at the host surface.

Dissolved oxygen amperometric sensor based on layer-by-layer assembly using host–guest supramolecular interactions

“…Several methods, which can be distinguished by the type of interaction between layers, have proven the feasibility of this approach. This method can be readily generalized to extend to a variety of materials such as polymers, nanoparticles, clay-like nanosheets and even biomaterials (enzymes and proteins) and can be supported by electrostatic interactions [29], hydrogen-bonding interactions [30], covalent assembly [31] and host-guest interactions [32].…”

Modeling of Electrochemical Hydrogen Storage in Metal Hydride Electrodes

“…It is generally accepted that the electrical double layer can be described by a simple capacitor, especially when the diffuse double layer can be considered negligibly small in concentrated electrolytes. 22,23 Referring to Fig. 1, the electrical double layer of the present MH electrode can obviously have up to four different components: Both the ␣ and ␤ phases can either be covered or uncovered by adsorbed hydrogen.…”

Electron Transfer and Molecular Recognition in Metallocene‐Containing Dendrimers

“…This group moved on to perform a series of elegant studies on the interaction between dendrimers containing multiple surface guest units, such as adamantyl or ferrocenyl, and gold surfaces covered with self-assembled monolayers prepared with complementary host (βCD) monomers. [9] These are multivalent interactions involving several guest units from an individual dendrimer that interact simultaneously with several binding cavities in the cyclodextrin monolayer. The multivalent aspect of the interaction adds considerable thermodynamic stability to the assembly, leading to the robust immobilization of the dendrimers on the monolayercovered surfaces.…”