A fluorescence "turn-on" chemosensor for Hg2+ and Ag+ based on NBD (7-nitrobenzo-2-oxa-1, 3-diazolyl). Issue 1 (3rd January 2017) - Lee, Seong Youl
Abstract : A fluorescence "turn-on" chemosensor for the simultaneous detection of Hg 2+ and Ag + was developed and practically applied with test strips. Abstract : A new fluorescent sensor1 was prepared by bridging a 7-nitrobenzo-2-oxo-1, 3-diazolyl (NBD) fluorophore with a dimethyl ethylene amine group via an ethylamine spacer. Distinct "turn-on" fluorescence changes of1 were observed upon the addition of Hg 2+ and Ag + in the aqueous solution. The sensor1 showed high sensitivity toward Hg 2+ and Ag + with detection limits of 0.05 μM and 0.12 μM, respectively. Moreover, the sensing abilities of1 for Hg 2+ and Ag + were successfully carried out in real water samples, and1 functioned as fluorescent test strip with silica plate. The sensing mechanisms of1 with Hg 2+ and Ag + were studied by using photophysical experiments, NMR titration, and ESI-mass spectrometry analysis. Moreover, turn-on fluorescence of1 toward Hg 2+ and Ag + caused by photo-induced electron transfer (PET) was explained by density functional theory (DFT) calculations.