CONTROLLED ORIENTATION OF CYCLODEXTRIN DERIVATIVES IMMOBILIZED ON GOLD SURFACES

Several different cyclodextrinthiol derivatives have been immobilized on gold surfaces through a chemisorption process to form films which e xhibit significantly different features. Three monothiolated cyclodext rin derivatives with different spacers between the cyclodextrin cavity and the thiol group and a mixture of multithiolated cyclodextrins wer e synthesized and characterized. Chemisorption of these compounds onto gold surfaces gave films which were investigated by Fourier transform infrared (FTIR) spectroscopy, time-of-flight mass spectrometry, conta ct angle measurements, plasmon surface polariton (PSP) spectroscopy, a nd cyclic voltammetry. It was found that the chemical structure of eac h cyclodextrin derivative had a strong influence on the molecular arch itecture in the resulting films, and in particular on the orientation of the cyclodextrin torus. Models were developed to describe the molec ular arrangement in the films.