A new coumarin schiff based fluorescent-colorimetric chemosensor for dual monitoring of Zn2+ and Fe3+ in different solutions: An application to bio-imaging

A new coumarin based dual chemosensor (probe 1) was devised and synthesized. Probe 1 could recognize Zn2+ and Fe3+ ions in different solutions through two approaches: a significant turn-on fluorescence response caused by Zn2+ and a visible color change from colorless to brown induced by Fe3+. The studies of sensing processes showed that probe 1 had excellent selectivity for Zn2+ and Fe3+ ions over many environmentally relevant ions, and high sensitivity with the detection limit in nanomolar level. The mechanisms of probe 1 for sensing Zn2+ and Fe3+ have been well demonstrated by Job's plot, Benesi-Hildebrand studies, Fourier Transform Infrared (FTIR) spectra, H-1 NMR titration and Mass spectra. Moreover, theoretical calculations strongly backed the proposed sensing mechanisms. Furthermore, probe 1 has the ability to be practical, visible, quick to monitor Zn2+ and Fe3+ ions by simple test strips. Importantly, possible utilization of probe 1 as bio-imaging fluorescent sensor to detect Zn2+ in human cancer cells was also observed by fluorescent cell imager. (C) 2018 Elsevier B.V. All rights reserved.