Interfacial molecular recognition. Binding of ferrocenecarboxylate to beta-aminocyclodextrin hosts electrostatically immobilized on a thioctic acid monolayer

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