Highly selective and sensitive detection of Pb2+ and UO22+ ions based on a carboxyl-functionalized Zn(II)-MOF platform

Designing highly efficient fluorescent sensors for detection of toxic pollutants has aroused great interest. In this work, a carboxyl-functionalized Zn(II) metal-organic framework (MOF), [Zn(HL)(bipy)(0.5)(H2O))center dot 2H(2)O (1) [H3L = 9-(4-carboxy-phenyl)-9H-carbazoly-3,6-dicarboxylic acid, bipy = 4,4'-bipyridine] was successfully synthesized. Crystal structure analysis reveals that 1 possesses a three dimensional (3D) unimodal 6-connected network. 1 can sense Pb2+ and UO22+ ions in aqueous solution by fluorescence quenching. High selectivity and sensitivity of 1 to toxic ions reveals it is a good bi-functional chemical sensor.