Synthesis, structure, and properties of a novel naphthalene-derived fluorescent probe for the detection of Zn2+

Abstract

• Crystal structure of a new schiff base fluorescent “turn-on” chemosensor . • Highly sensitive and selective molecule towards Zn 2+ ions in aqueous medium. • “Naked-eye” detection of Zn 2+ ions. • The lowest detection limit of 8.94 × 10 −8 M and minimum response time for the sensing of Zn 2+ ions. A novel naphthalene-based schiff base (L) was synthesized as a good “turn-on” fluorescent sensor for recognizing of Zn 2+ . The probe showed excellent selectivity for Zn 2+ over most other competing ions in DMF/H 2 O solution, which might be attributed to the chelation enhanced fluorescence (CHEF) mechanism. The reaction stoichiometry 3:1 between L and Zn 2+ was determined based on the Job’s plot and 1 H NMR spectra. The binding constant of the complex was calculated to be 1.07 × 10 5 M −3 with a detection limit of 8.94 × 10 -8 M. The time-response study displayed that fluorescence intensity rapidly boosted and reached the stable value in less than 1.0 min. Meanwhile, the potential application of L in actual samples for recognizing Zn 2+ was investigated. These results indicated that L could be a favorable probe for Zn 2+ detection.