Selective monitoring of Cu(II) with a fluorescence-on naphthalene-based probe in aqueous solution

The novel naphthalene- and pyridine-containing Schiff base derivative L has been synthesized via one-pot reaction and its high selectivity for Cu2+ ions detection in nearly 100% aqueous buffer solution with fluorescence enhancement is reported. The 2: 1 complexation stoichiometry of L with Cu2+ was calculated from Job's plot and ESI-MS analysis. The limit of detection (LOD) of L for Cu2+ is 3.90 x 10(-3) mu M and the association constant (K-a) for Cu2+ binding with L is 1.38 x 10(5) M-2. Furthermore, the L-Cu2+ complex could be used as a highly selective fluorescent sensor for S2- detection without obvious interference in the presence of other anions.