A highly sensitive turn-on fluorescent chemosensor for recognition of Zn2 + and Hg2 + 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 Zn 2   + and Hg 2   + 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 (Zn 2   + ) and 2.50   ×   10 −   7   M (Hg 2   + ). Moreover, based on DFT, the geometry optimizations of probe 1, [1-Hg 2   + ] complex and [1-Zn 2   + ] 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 Zn 2   + and Hg 2   + in living cells.