A coumarin based fluorescent probe for rapidly distinguishing of hypochlorite and copper (II) ion in organisms.

A dual-functional fluorescent probe based on coumarin fluorophore for monitoring ClO- and Cu2+ was synthesized and characterized. The identification mechanisms for ClO- and Cu2+ induced different colorimetric and ratiometric changes. ClO- caused a colorimetric change from yellow to colorless and 120 nm blue-shifted emission spectra from red to blue. Besides, Cu2+ induced a remarkable fluorescence quenching behavior and 36 nm blue-shifted absorption spectra accompanied by the color change from yellow to luminous yellow. As expected, Probe 1 displayed excellent selectivity and sensitivity for detecting ClO- and Cu2+ over other competing ions in their respective systems. The limits of detection for ClO- and Cu2+ were 24.62 nM and 0.39 nM, respectively. The recognition mechanisms were proved by 1H NMR, mass spectrum and theoretical calculations. More importantly, the reversibility of Cu2+ could be applicable to rapid quantification for ClO-/Cu2+. Thus, the strategy for sensing ClO-/Cu2+ was carried out, which revealed broad applications of Probe 1 in multiple actual water and biology.