A Highly Selective Hg²⁺ Fluorescent Chemosensor Based On Photochromic Diarylethene With Quinoline Unit

A novel diarylethene-based fluorescent chemosensor containing a quinoline unit (1o) had been designed and synthesized. 1o showed good photochromic ability and fluorescence switching properties by alternating UV/vis light irradiation. The chemosensor showed high "Turn-off" fluorescent selectivity for Hg²⁺ by competitive tests of the fluorescence reaction in the presence other ions in acetonitrile solution. The stoichiometry between the compound 1o and Hg²⁺ was 1:1 by Job's plot curve and HRMS analysis. In addition, the LOD for Hg²⁺ was calculated as 60 nM. The fluorescence emission can be back to the "Turn-on" state by adding EDTA. Based on these facts, a molecular logic gate that including four input signals (UV/vis and Hg²⁺/EDTA) and one output signal (fluorescent intensity at 491 nm) was designed.