A coumarin based azo-phenol ligand as efficient fluorescent OFF-ON-OFF chemosensor for sequential detection of Mg2+ and F-: Application in live cell imaging and as molecular logic gate

A novel coumarin based azo-phenol ligand (H2L) has been synthesized and characterized by several spectroscopic techniques. An almost 16 fold enhancement of emission intensity has been observed upon gradual addition of Mg2+ to H2L in DMSO:H2O (1:5 v/v) medium while it has no significant effect in emission intensity even in presence of other metal ions. The emission intensity of L-Mg2+ complex has almost quenched on gradual addition of F- to it. The limit of detection for both Mg2+ and F- are of 10(-8) mu M order, hence the newly developed chemosensor is highly efficient in detecting Mg2+ and F- in very minute levels. The chemosensor can even detect Mg2+ in the intracellular region of human lung cancer cells (A549 cells). (C) 2017 Elsevier B.V. All rights reserved.