A luminescent lanthanide MOF for selectively and ultra-high sensitively detecting Pb2+ ion in aqueous solution
A luminescent lanthanide metal−organic framework [Tb(L)(H2O)5]n•solvents (Tb−MOF, H2L− = 3, 5-dicarboxy-phenol anion ligand) with 2D network structure was synthesized. The size of Tb−MOF single crystal can reach to 6 mm; such a large-scale single crystals of MOFs was rarely reported in literatures. Tb−MOF exhibits a strong green luminescence induced by the efficient antenna effect of the ligands. Importantly, it shows an excellent recognition ability on detecting Pb2+ ion which is a noxious inorganic pollutant and cause permanent damage to human health and living environments. The perfect linear correlation between the luminescence intensity of Tb-MOF and the concentration of the Pb2+ ions provides this crystal as a reliable and easy-to-use luminescent sensor, which can be applied in pollutant monitoring. As far as we know, it is the first example of high-efficiency luminescent MOF sensor with millimeter level for detecting Pb2+ ion at a very low concentration with detection limit to 10−7 M.