Development of an electroactive layer-by-layer assembly based on host–guest supramolecular interactions

The development of a novel electrochemically stable host–guest supramolecular complex at a host surface is described. It was constructed by combining a self-assembled monolayer (SAM) of mono-(6-deoxy-6-mercapto)-β-cyclodextrin (βCDSH), iron (III) tetra-(N-methyl-4-pyridyl)-porphyrin (FeTMPyP) as the guest-link-molecule and β-cyclodextrin-functionalized gold nanoparticles (βCDAuNP). The building process of the layer-by-layer assembly was monitored by surface plasmon resonance spectroscopy (SPR). The binding processes between the host-functionalized gold surface and the linker molecule (FeTMPyP) were verified to be monovalent, and for host-functionalized gold nanoparticles with FeTMPyP, the interaction was determined to be bivalent. Finally, the electrochemical properties of the electroactive supramolecular multivalent film were determined.