A highly selective and sensitive fluorescent chemosensor and its application for rapid on-site detection of Al3+

In this paper, a simple naphthalene-based derivative (HL) has been designed and synthesized as a Al3+-selective fluorescent chemosensor based on the PET mechanism. HL exhibited high selectivity and sensitivity towards Al3+ over other commonly coexisting metal ions in ethanol with a detection limit of 2.72 nM. The 1:1 binding stoichiometry of the complex (HL-Al3+) was determined from the Job's plot based on fluorescence titrations and the ESI-MS spectrum data. Moreover, the binding site of HL with Al3+ was assured by the H-1 NMR titration experiment. The binding constant (Ka) of the complex (HL-Al3+) was calculated to be 5.06 x 10(4) M-1 according to the Benesi-Hildebrand equation. In addition, the recognizing process of HL towards Al3+ was chemically reversible by adding Na(2)EDTA. Importantly, HL could directly and rapidly detect aluminum ion through the filter paper without resorting to additional instrumental analysis. (C) 2017 Elsevier B.V. All rights reserved.