Observing Host–Guest Interactions at Molecular Interfaces by Monitoring the Electrochemical Current

Macrocyclic cucurbit­[n]­uril (CB­[n]) molecules have triggered renewed interest because of their outstanding capabilities as host molecules to selectively interact with a wide range of small guest molecules. Here, CB[7]-based host–guest interactions were investigated for a guest-modified nanoelectrode by monitoring the electrochemical current. A ferrocene (Fc)-terminated molecule immobilized on a gold nanoelectrode (GNE) showed suitable affinity with CB[7] when the effective exposing area of the GNE was between 5.3 and 12 μm2 and the bias applied on the GNE was −500 mV. Monitoring the dynamics of nanoparticles (NPs) on a nanoelectrode provides new insights into the host–guest interactions at molecular interfaces.