Stable Zinc(II) Coordination Polymer as a Rapid and Highly Sensitive Fluorescence Sensor for the Discriminative Sensing of Biomarker 2-(2-Methoxyethoxy) Acetic Acid

:a novel two-dimensional bilayer Zn-based luminescent coordinationpolymer (LCP) [Zn2(mu 2-OH)(4-dptp)(3,4 ',5-bpt)] (LCP1)[4-dptp=N3,N4-bis(pyridin-4-ylmethyl)thiophene-3,4-dicarboxamide and 3,4 ',5-H3bpt = biphenyl-3,4 ',5-tricarboxylic acid] was successfully prepared under hydrothermal conditionsand characterized by single-crystal X-ray diffraction, IR spectroscopy, powder X-raydiffraction, and luminescence spectroscopy. LCP1displayed excellentfluorescence-quenching efficiency toward a biomarker 2-(2-methoxyethoxy) acetic acid (MEAA)with a highKsv(5.153x104 M-1), a low limit of detection (0.244 mu M), and a rapidresponse time (28 s). Additionally, LCP1can repeatedly detect MEAA at least eighttimes with excellent stability. The sensing mechanism was also carefully investigatedthrough UV-vis absorption spectroscopy, density functional theory calculations, andfluorescence lifetime analysis