A new coumarin-derived fluorescent sensor with red-emission for Zn2+ in aqueous solution.

Abstract: A new sensor (LWZn) based on 7-diethylaminocoumarin Schiff base was synthesized to detect Zn2+ in the red emission region due to its extended π-conjugation structure and the strong electron-withdrawing capability of nitrile groups. Although LWZn alone has weak fluorescence, its fluorescence intensity shows a 35-fold increase after combining with Zn2+ probably due to the inhibition of the conformational change in the excited state upon complexation with Zn2+. In addition, LWZn shows a good selectivity to Zn2+ over other metal cations, especially Cd2+, which often responds together with Zn2+. [Copyright &y& Elsevier]