A dual chemosensor: Colorimetric detection of Co2+ and fluorometric detection of Zn2+

A new dual chemosensor 1was designed and synthesized. Receptor 1 detected Co2+ via color change and Zn2+ with turn-on fluorescence in a 1:1stoichiometric system, respectively. The response mechanisms of 1-Co2+ and 1-Zn2+ complexes have been analyzed using UV-vis spectroscopy, fluorescence titration, ESI-mass spectrometry analysis, NMR titration and DFT calculations. Importantly, the detection limit of 1 for Co2+was down to 0.34 μM a near-perfect aqueous solution, which is the lowest one among those previously reported for organic chemosensors for sensing of Co2+. 1 was also used to quantify Co2+ in real water samples. Therefore, a versatile chemosensor 1 could be a great method for detecting of both Co2+ and Zn2+