A highly selective turn-on chemosensor for Zn2+ in aqueous media and living cells

Abstract

A new simple quinoline-based chemosensor 1 was synthesized for Zn2+. 1 showed the selective fluorescence enhancement in the presence of Zn2+ with a 1:1 stoichiometry in a near-perfect aqueous solution (bis-tris buffer:DMSO= 999:1), which was reversible with the addition of ethylenediaminetetraacetic acid (EDTA). The detection limit (0.6 M) of 1 for Zn2+ was much lower than World Health Organization guideline (76 p,mu M) in drinking water. 1 was successfully applied to quantify and image Zn2+ in water samples, test kit and living cells. The sensing mechanism of Zn2+ by 1 via the intramolecular charge transfer was explained by theoretical calculations.