Rhodamine and functionalised azobenzene condensed fluorescent novel receptor for the selective and sensitive detection of Hg: a combined experimental and theoretical study.

Rhodamine dye has a high absorption coefficient, fluorescence quantum yield, photostability, and extended wavelengths that make it a promising fluorescent probe. A rhodamine and functionalised azobenzene condensed novel chemosensor L has been reported for the first time to detect Hg in aqueous ethanol optically in this investigation. Chemosensor L's fluorescence activation in response to Hg is due to the suppression of PET and CHEF processes and the change from spirolactam to ring-opened amide. Time-resolved photoluminescence studies confirmed the PET and CHEF processes, whereas C-NMR and infrared spectroscopy confirmed the spirolactam ring opening. The opened spirolactam ring forms a 1 : 1 binding complex with Hg, as shown by its high binding constant. L can be successfully applied for the formation of a INHIBIT type of logic gate and real sample analysis.