A novel on-off fluorescent probe with rapid response for the selective and sensitive detection of Co2

In this communication, we design and synthesize a simple, high efficient on-off fluorescent probe CMP based on coumarin and purine derivatives. In the presence of Co2+, the probe CMP exhibits significant fluorescence quenching with high selectivity, sensitivity and rapid response (within 1 min). Moreover, the detection limit of this CMP to Co2+ was calculated to be 0.487 μM, which clearly suggested that the probe CMP was efficient in detecting Co2+ in very minute level. [Display omitted] •CMP is used as a novel on-off fluorescent probe for detection of Co2+ with a 1:1 coordination between probe CMP Co2+.•CMP shows high sensitivity and selectivity to Co2+ with a low the limit of detection as 0.487 μM.•CMP displays rapid response (within 1 min) to Co2+.•The binding modes of CMP with Co2+ has been demonstrated by Job's plot, MS spectra and DFT calculation. A simple, efficient on-off fluorescent probe 7-(diethylamino)-N'-(8-methyl-9- (naphthalen-1-yl)-9H-purin-6-yl)-2-oxo-2H-chromene-3-carbohydrazide (CMP) based on coumarin and purine derivatives has been rotationally designed, synthesized and characterized. Interestingly, the novel fluorescent probe CMP exhibited a highly sensitive, selective and quick response (within 1 min) to Co2+ in HEPES buffer solution (pH 7.4), and with a low detection limit (0.487 μM). Notably, visual color change was observed with the addition of Co2+ to the probe CMP, its color changed from yellow to pink. Moreover, the binding stoichiometry of CMP with Co2+ was determined to be 1:1 by Job’s plot and MS spectra analysis, and the binding mechanism of them was further demonstrate by density functional theory (DFT) study. This novel probe CMP provided a new method for rapid and naked-eye recognition of Co2+ with a cheap and easy-to-make process, high efficiency and stable storage.