CyDs binding properties

The binding properties of o-, m-, and p-nitrophenols to the oriented-CyD-polymer in water were estimated by incubating 1 mg of nitrophenols and 20 mg of the pol)nner in 20 ml of water at 25 C for 25 h. Absorption spectroscopy on the liquid phase, obtained after the separation of the polymer-nitrophenol complex by centrifugation, showed that the amounts of o-, m-, and p-nitrophenols bound to 20 mg of the polymer were 0.03, 0.09, and 0.36 mg, respectively. Thus, the difference in the permeation rates of nitrophenols ( m p > o ) cannot... 

Biotin-appended dansyl-modified CyDs 52, 53 were prepared to examine the effects of avidin binding on guest-inclusion phenomena and fluorescence properties [168]. The fluorescence intensities of these CyDs were enhanced more than three times by avidin. The avidin forces the dansyl moiety into the CyD cavity, so that the dansyl moiety is then excluded to the hydrophobic environment of the avidin rather than to the bulk water associated with guest binding. The binding is stronger in the presence of avidin as a hydrophobic cap. 

Another widely described role for electrochemical methods in the field of CyDs is the external on/off switching of binding events or opening/closing biomimetic CyD channels. Electrochemical measurements are often employed to explain the chemical reactions taking place inside the cavity and to rationalize the catalytic properties of the CyD microenvironment. 

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