A coumarin-derived fluorescent chemosensor for selectively detecting Cu²⁺: Synthesis, DFT calculations and cell imaging applications

A novel coumarin-based fluorescent probe L ((4E)-4-((7-hydroxy-4-methyl-2- oxo-2H-chromen-8-yl) methyleneamino)-1,2-dihyydro-2,3-dimethyl-1-phenylpyrazol- 5-one) has been developed as a simple and efficient chemosensor which exhibits a significant fluorescence reduction in the presence of metal cations. This sensor exhibits high selectivity and sensitivity toward Cu²⁺ over other common cations. The mechanism for detecting copper was evaluated by time-dependent density functional theory (TD-DFT) calculations and the coordination mode was also confirmed by density functional theory (DFT) calculations. Furthermore, results of cell imaging in this study indicate that this new probe may be useful for detection and monitoring of Cu²⁺ in biological applications.