A highly selective and sensitive fluorescent chemosensor and its application for rapid on-site detection of Al.

In this paper, a simple naphthalene-based derivative (HL) has been designed and synthesized as a Al-selective fluorescent chemosensor based on the PET mechanism. HL exhibited high selectivity and sensitivity towards Al over other commonly coexisting metal ions in ethanol with a detection limit of 2.72nM. The 1:1 binding stoichiometry of the complex (HL-Al) was determined from the Job's plot based on fluorescence titrations and the ESI-MS spectrum data. Moreover, the binding site of HL with Al was assured by the H NMR titration experiment. The binding constant (Ka) of the complex (HL-Al) was calculated to be 5.06×10M according to the Benesi-Hildebrand equation. In addition, the recognizing process of HL towards Al was chemically reversible by adding NaEDTA. Importantly, HL could directly and rapidly detect aluminum ion through the filter paper without resorting to additional instrumental analysis.