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A fluorescence “on–off” sensor for the highly selective and sensitive detection of Cu 2+ ion
Author(s) -
Zhang Han,
Qu Yao,
Zhao Kun,
Wang Cong,
Wu Yancong,
Wu Huilu
Publication year - 2020
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.201900337
Subject(s) - chemistry , detection limit , analytical chemistry (journal) , fluorescence , copper , quenching (fluorescence) , ion , selectivity , proton nmr , mass spectrometry , binding constant , fluorescence spectroscopy , stereochemistry , chromatography , organic chemistry , binding site , biochemistry , physics , quantum mechanics , catalysis
In an attempt to obtain a model of copper(II) ion‐selective sensors, a new 1,8‐naphthalimide‐based fluorescence chemosensor, N ‐allylamine‐4‐[(E)‐4‐(([2‐aminoethyl]imino)methyl) benzene‐1,3‐diol]‐1,8‐naphthalimide (NABN), was designed and synthesized. The sensor NABN is fully characterized by melting point analysis, fourier transform infrared spectra, Ultraviolet–visible (UV–vis) spectra, fluorescence spectra, 1 H NMR and 13 C NMR spectroscopy, and mass spectrometry. NABN showed an unrivaled sensing behavior and an ardent selectivity toward copper(II) ion over other competitive metal ions tested in solution (N,N‐Dimethylformamide (DMF)/Tris–HCl buffer, 1:1, v/v, pH = 7.2). The sensor showed a linear fluorescence quenching toward copper(II) ion in the range 0–50 μM, with a detection limit of 1.92 × 10 −7 M estimated. Job's method indicated the formation of a 2:1 coordinative mode of the sensor with copper(II) ion with a high threshold of binding constant of 4 × 10 12 M −1 . Combining the above results, the quenching response of NABN toward Cu(II) ions could be ascribed to the strong, intrinsic paramagnetic behavior of Cu(II).