Use of CDs in electrochemical analysis

Recently, a regioselective electrode system with a poly (perfluorosulfonic add)-coated electrode based on CDs complexation for the determination of o-nitrophenol in the presence of p-nitrophenol has been developed [37]. The p-nitrophenol shows an extraordinarily small reduction peak on a regioselective electrode in or-CD solution, whereas there is no effect of or-CD on o-nitrophenol. This system is 33 times more sensitive to o-nitrophenol than to p-nitrophenol and provide an accurate determination of o-nitrophenol in the presence of its para isomer. 

A potentiometric enantioselective membrane electrode with bonded 2-hydroxy-3-trimethyl-ammoniopropyl-/3-CD has been used for the enantio-purity determination of several L-enantiomers. The /3-CD-ferrocene inclusion complex has been used for the amperometric determination of ascorbic acid. Alkylated a-, P- and y-CDs have been incorporated in an ion-selective electrode as neutral ionophores and this electrode was used for the potentiometric andamperometric determination of the tricyclic antidepressives and their hydrochloride salts [80]. Cyclic voltammetry was used for measuring the association constants of inclusion complexes. 

---