The interfacial binding properties of electrodes prepared by the electrostatic immobilization of an adlayer of positively charged beta-aminocyclodextrin (beta-ACD) hosts on a self-assembled monolayer of thioctic acid on gold were investigated using Osteryoung square wave voltammetry. The results indicate that the water-soluble ferrocenecarboxylate (Fc-COO-) guest was effectively bound by the interfacial beta-ACD hosts, with binding constants in the range (2-5) x 10(4) M-1. The measured binding constants were found to increase slightly with the surface density of immobilized hosts.