Preparation and electrochemical characterization of a beta-cyclodextrin-based chemically modified electrode

The preparation and the voltammetric characterization of a chemically modif ied electrode (CME) based on a suitable thiolate beta-cyclodextrin (beta cD ) derivative in the form of self-assembled monolayer (SAM) is described. Th e quality of SAM was studied by double layer capacitance measurements, redu ctive desorption and cyclic voltammetry. Species unable (hexacyanoferrate) or able (ferrocenecarboxylic acid and hydroquinone) to permeate the beta CD cavity were used to test the CME by cyclic voltammetry. The CME can work a s channel sensor so it can be used for the detection of nonelectroactive an alytes forming a strong inclusion complex with beta CD if a suitable marker able to permeate the beta cD cavity is used. This approach was also used f or the evaluation of the conditional constants of the surface host-guest co mplexes formed by beta CD with analytes in test (trimethyilcetylammonium io n and ursodeoxycholic acid).