A ratiometric fluorescent chemosensor for Cr~(3+) based on monomer-excimer conversion of a pyrene compound

摘要

A pyrene compound (1) containing piperazine was synthesized and used as ratiometric fluorescent chemosensor to recognize Cr~(3+). The ratiometric fluorescent signal change of the chemosensor is on the basis of monomer-excimer conversion of 1 induced by Cr~(3+). As far as we know, it is the first ratiometric chemosensor based on pyrene that is developed for Cr~(3+). The analytical performance characteristics of the proposed Cr~(3+)-sensitive chemosensor were investigated. The chemosensor can be applied to the quantification of Cr~(3+) with a linear range covering from 2.0 × 10~(-7) to 1.0 × 10~(-5) M with the detection limit is 4 × 10~(-8) M. The experiment results show that the response behavior of 1 towards Cr~(3+) is pH independent in medium condition (pH 6.0-8.0). Most importantly, the fluorescence changes of the chemosensor are remarkably specific for Cr~(3+) in the presence of other metal ions, which meet the selective requirements for practical application. Moreover, the response of the chemosensor toward Cr~(3+) is fast (response time less than 2 min). In addition, the chemosensor has been used for determination of Cr~(3+) in real sample such as river and pond water with satisfactory results.