Chemosensors Using Modified Cyclodextrins

The 2-naphthylamine-appended jS-CyD-calix[4]arene couple 49 showed sensitivity for analytes such as steroids and terpenes with different selectivity from the native CyD. On the other hand, the dansyl-appended j8-CyD-calix[4]arene couple 50 did not show any change in fluorescence intensity upon the addition of guests because of the strong inclusion of the dansyl group into the CyD cavity [166]. 

Monensin is an antibacterial hydrophobic agent that is expected to act as a hydrophobic cap responsive to sodium ion, if monensin is introduced to the primary face of the CyD. A monensin-capped dansyl-modified j8-CyD 51 was prepared as 

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. 

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Chemosensors for Detecting Molecules using Modified Cyclodextrins and Cyclodextrin-Peptide Conjugates... 

There has been considerable interest in the development of new methods of chemical sensing to recognize molecules or ions as important application of supramolecular chemistry [1-3]. Our group has prepared many kinds of chro-mophore-modified cyclodextrins (CD) as chemosensors for detecting molecules [4-8]. Colorless neutral molecules can be detected as changes in the intensities of the fluorescence, absorption, or circular dichroism using chemosensors based on chromophore-modified CD. 

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