A highly sensitive turn-on fluorescent chemosensor for recognition of Zn 2+ and Hg 2+ and applications.

A fluorescence probe has been designed and synthesized, and applied with a combined theoretical and experimental study. Research suggests that the probe can be used to sense Zn2+ and Hg2+ through selective turn-on fluorescence responses in the aqueous HEPES buffer (0.05M, pH=7.4). The limit of detection (LOD) were determined as 1.46×10-7 M (Zn2+ ) and 2.50×10-7 M (Hg2+ ). Moreover, based on DFT, the geometry optimizations of probe 1, [1-Hg2+ ] complex and [1-Zn2+ ] complex were carried out using the Gaussian 09 program, in which the B3LYP function was used. The electronic properties of free probe 1 and the metal complexes were studied based on the Natural Bond Orbital (NBO) analyses. The probe 1 has also been successfully applied to detection of Zn2+ and Hg2+ in living cells.