A novel colorimetric and "turn-on" fluorimetric chemosensor for selective recognition of CN - ions based on asymmetric azine derivatives in aqueous media.

A novel chemosensor 2-((Z)-(((E)-quinolin-2-ylmethylene)hydrazono)methyl)phenol PX has been successfully designed and synthesized, which showed both colorimetric and "turn-on" fluorescence responses for CN- in DMSO/H2 O (3:2, v/v; pH=7.20) solution. The sensor could respond effectively to the stimulation of CN- ions via deprotonation and sensing mechanism of intramolecular charge transfer (ICT). Moreover, the sensor PX was successfully utilized to detect CN- in bitter almond, and the detection limit on fluorescence response of PX towards CN- was down to 4.5×10-7 M. Test strips containing PX were also prepared, which could act as a practical colorimetric tool to detect CN- in aqueous media.