Rhodafluor-based chromo- and fluorogenic probe for cyanide anion

A rhodafluor-based chromo- and fluorogenic probe for CN- has been designed, synthesized, and characterized. The probe comprises a spectroscopic unit of rhodafluor and a CN--specific trifluoroacetylamino binding unit. The probe itself is colorless and nonfluorescent because of its spirocyclic structure, whereas ring-opening of the corresponding spirolactone induced by CN- gives rise to strong fluorescence emission and also clear color changes. In the system, an excellent selectivity toward the detection of CN- in aqueous solution over a wide range of tested anions was observed: moreover, most of the background anions have not any interference with the detection of CN-. (C) 2011 Elsevier B.V. All rights reserved.