Diaminomaleonitrile-based Fluorophores as Highly Selective Sensing Platform for Cu2+

Abstract

A colorimetric and turn-on fluorescent chemodosimeter 1 based on diaminomaleonitrile was synthesized for Cu 2+ detection. It showed high selectivity and sensitivity towards Cu 2+ over the other tested metal ions. Probe 1 in acetonitrile exhibited a strong absorption band at 530 nm and weak fluorescence emission when excited at 480 nm, while the addition of Cu 2+ could lead to a 30-nm blue shift of the absorption band and a remarkable fluorescence enhancement. Moreover, the detection limit of probe 1 for Cu 2+ was calculated to be 28 nM. Quite different from the reported mechanism based on a metal-complexation induced fluorescence enhancement, the sensing mechanism was proved to be based on the Cu 2+-promoted hydrolysis reaction, which was confirmed by 1 H NMR, 13 C NMR and mass spectrum analysis. Studies on probe 2 were carried out to verify the universality of this sensing mechanism.

A Novel Coumarin-based Fluorescent Probe for Recognition of Copper(II) Ions and Its Application in Bioimaging

“…Excessive intakes of copper(II) ions can cause many diseases, for instance liver cirrhosis and cerebrovascular diseases. [5][6][7][8][9][10] Copper(II) ions must be controlled at reasonable concentrations in living cells to maintain the normal functions of enzymes and the balance of intracellular metabolism. 11,12 It is necessary to develop a highly sensitive and selective copper(II) ions recognition method for environmental analysis and biological applications.…”