A new selective chromogenic and fluorogenic sensor for citrate ion

A new receptor 1 was developed, and its chromogenic and fluorogenic behaviors toward various di- and tricarboxylate anions were investigated. Receptor 1 shows response exclusively toward citrate anion and also distinguishes citrate anion from other anions by different color change in aqueous solution (DMSO/H2O = 4/1). In addition, the receptor 1 also exhibits a pronounced citrate-induced fluorescence enhancement. The detection limit for the citrate anion was determined as (0.18 ± 0.01 μM). Thus, the receptor 1 can be used as a colorimetric and fluorescent sensor for the determination of citrate ion.