Aromatimide tetracarboxylate metal-framework materials: Fluorescence sensing application towards NACs and small drug molecules

Three multifunctional fluorescent Metal-Organic Framework (MOF) sensors were synthesized based on N, N'-bis(3, 5-dicarboxyphenyl)isophthalic diimide (H4BDCPPI) with Zn, Cu, and Cd ions. Structural analysis shows that although using the same organic conjugated aromatic imide tetracarboxylic acids ligand, their corresponding structures are different. Based on luminescence characteristics of the organic components, they exhibit good luminescent properties and show sensitive detection capabilities for nitro aromatic compounds (NACs) and small drug molecules, with relatively low limit of detection (LOD). They can detect p-nitrophenol (PNP), 2,4-dinitrophenol (DNP), 2,4,6-trinitrophenol (TNP) and small drug molecules (colchicine and balsalazide disodium) selectively. The complex 1 is more sensitive for detection of TNP, compared to the other complexes. The mechanism of fluorescence sensing is proposed in detail based on analyses of PXRD, fluorescence lifetimes, and UV-vis spectra. This study explores the potential of MOFs based on H4BDCPPI in the field of fluorescence sensing for the first time, laying a theoretical foundation for the application value of complexes with conjugated aromatic imide tetracarboxylic acids.