Quinolinotriazole-beta-cyclodextrin and its adamantanecarboxylic acid complex as efficient water-soluble fluorescent Cd(2+) sensors.

Ying-Ming Zhang, Yong Chen, Zhi-Qiang Li, Nan Li, Yu Liu

Index: Bioorg. Med. Chem. 18(4) , 1415-20, (2010)

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Abstract

A novel beta-cyclodextrin derivative 1 bearing 8-hydroxyquinolino and triazole groups was synthesized in satisfactory yield by 'click chemistry'. With a good water solubility up to 0.03 mol/L, 1 exhibited an effective switch-on fluorescence response to Cd(2+) over other common metal ions under physiological conditions. Studies on the recognition mechanism indicated that the cooperative coordination of Cd(2+) with both the 8-hydroxyquinolino moiety excluded from the beta-CD cavity and the triazole moiety was a crucial and basic factor to achieve the fluorescent sensing process. Significantly, spectrophotometric studies also demonstrated that, after inclusion complexation with 1-adamantanecarboxylic acid sodium salt (AdCA), the resultant 1/AdCA system gave a more effective fluorescent sensing to Cd(2+) through a cyclodextrin/substrate/Cd(2+) triple binding mode.Copyright 2010 Elsevier Ltd. All rights reserved.