An intramolecular charge transfer fluorescent probe: synthesis and selective fluorescent sensing of Ag+.

An intramolecular charge transfer (ICT) fluorescent probe, in which the thiourea derivative moiety is linked to the fluorescent 4-(dimethylamino) benzamide, has been designed and synthesized. The ions-selective signaling behaviors of the probe were investigated. Upon the addition of Ag+, an overall emission enhancement of 14-fold was observed. Compound 1 displayed highly selective chelation enhanced fluorescence (CHEF) effect with Ag+ over alkali, alkali earth metal ions and some transition metal ions in aqueous methanol solutions. The prominent selective and efficient fluorescent enhancing behavior could be utilized as a new chemosensing probe for the analysis of Ag+ ion in aqueous environment.