Multiemission Ln-MOF Fluorescence Sensing Array for Identification of Antibiotic Residues in Environmental and Food Samples

The environmental residues and drug resistance resulting from antibiotic abuse urgently call for the development of efficient multicomponent detection technologies. Therefore, single-lanthanide metal-organic frameworks [Ln(BDPO)(H2O)4](H2O) (DMF): Ln = Eu, Tb, Gd, Dy; BDPO= N,N'-bis(3,5-dicarboxyphenyl)-oxalamide are designed and synthesized, and the ternary mixed-metal MOFs are constructed. Single-crystal X-ray diffraction analysis shows that the series MOFs belong to the triclinic P1̅ space group with a one-dimensional chain structure. Optical performance tests confirm that Eu-MOF and Tb-MOF exhibit ligand-to-rare-earth ion ″antenna effect″ that allows for dual-emission ratio fluorescence response. Based on this, Eu-MOF and Tb-MOF exhibit high sensitivity and quantitative detection capabilities for ciprofloxacin and ofloxacin. The multiemission centers of EuTbGd-MOF show differential responses identify seven types of antibiotics when combined with linear discriminant analysis (LDA), principal component analysis (PCA), and hierarchical cluster analysis (HCA). Real sample testing demonstrate that the sensor array can effectively identify target antibiotics even in milk and tap water matrices. This study provides a new sensing platform for the highly selective detection of multicomponent pollutants in complex systems, offering significant application prospects in environmental monitoring and food safety.