A hydrogen bond forming tris(amide) receptor based on cyclotriveratrylene (CTV) was prepared. 1H NMR and UV measurements confirm that the receptor exhibits the highest affinity for acetate ions among the anions studied. Self-assembled monolayers (SAMs) of the receptor were formed on gold surfaces and characterized by electrochemical blocking, impedance spectroscopy and electrochemical desorption experiments. Impedance responses obtained by employing both negatively and positively charged redox couples confirmed that selective acetate anion binding occurred on the surfaces. Upon binding acetate anions, the monolayer modified gold electrodes show a drastic increase of the Rct values when Fe(CN)63-/4- is used as the redox probe. When the probe was changed to a positively charged one, Ru(NH3)63+/2+, the Rct values decreased monotonically as the acetate concentration was increased, thus confirming the accumulation of negative surface charge upon anion binding. H2PO4- shows some interference when sensing AcO-. Other monovalent anions such as Cl-, Br-, NO3-, and HSO4- do not bind to the CTV receptor either in solution or on the surfaces.
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