A coumarin based azo-phenol ligand as efficient fluorescent 'OFF-ON-OFF' chemosensor for sequential detection of Mg~(2+) and F~-: Application in live cell imaging and as molecular logic gate

摘要

A novel coumarin based azo-phenol ligand (H_2L) has been synthesized and characterized by several spectroscopic techniques. An almost 16 fold enhancement of emission intensity has been observed upon gradual addition of Mg~(2+) to H_2L in DMSO:H_2O (1:5v/v) medium while it has no significant effect in emission intensity even in presence of other metal ions. The emission intensity of L-Mg~(2+) complex has almost quenched on gradual addition of F~- to it. The limit of detection for both Mg~(2+) and F~- are of 10~(-8) M order, hence the newly developed chemosensor is highly efficient in detecting Mg~(2+) and F~ in very minute levels. The chemosensor can even detect Mg~(2+) in the intracellular region of human lung cancer cells (A549 cells).