Electrochemical recognition of ions with self-assembled monlayers of calixarenes

Abstract

Quinone-functionalized calix[4]arenes with carboxylic acid groups or disulfide group were prepared and their spontaneous adsorption respectively on silver and gold surface was studied. Since the cavity-like structure of calixarenes was immobilized, they exhibited selective affinity towards specific metal ions in aqueous media. Voltammetric as well as EQCM and spectroscopic studies showed the well-ordered deposition of organic receptors and entrapment of metal ions. And it also was found that the repeated capture and removal of metal ions reversibly with chelating agents such as ethylenediaminetetraacetic acid (EDTA) was possible. This is the first example, in our knowledge, of voltammetric detection of metal ions in aqueous media using a chemically modified electrode with redox-active macrocyclic receptors.