Electrochemistry of Redox-Active Guest Molecules at β-Cyclodextrin-Functionalized Silicon Electrodes.

Functionalization of silicon-based sensing devices with self-assembled receptor monolayers offers flexibility and specificity towards the requested analyte as well as the possibility of sensor reuse. As electrical sensor performance is determined by electron transfer, we functionalized H-terminated silicon substrates with β-cyclodextrin (β-CD) molecules to investigate the electronic coupling between these host monolayers and the substrate. A trivalent (one ferrocene and two adamantyl moieties), redox-active guest was bound to the β-CD surface with a coverage of about 10 mol/cm and an overall binding constant of 1.