Fluorescent metal–organic frameworks (MOFs) have been widely developed as sensor matrix for single-target detection. Multi-target sensing with MOFs can be more efficient and cost-effective but relevant studies is still in its infancy. Here we report the construction of novel fluorescent Eu-MOF with electron-deficient, thiadiazole-functionalized ligand, 4,4′-(benzo[c][1,2,5]thiadiazole-4,7-diyl)dibenzoic acid (H₂-TTPDC) as organic linkers, and Eu³⁺ ions as metal nodes for dual-target detection. Thanks to the conjugated structure and thiadiazole active group of the ligand, and the large pore structure of the MOF, sensitive detection of both ethylamine and gossypol was achieved with a detection limit of 1.30 μM and 4.32 μM, respectively. Strong hydrogen bonds between ethylamine and TTPDC result in the extended π-conjugation and thus give rise to the fluorescence “turn-on” detection of ethylamine with the Eu-MOF. Electron transfer caused by host–guest conjugation and strengthened π-π packing effect synergistically realize the “turn-off” sensing of gossypol. The precise emission change enabled by the intramolecular rotation structure of TTPDC facilitate the validation of the interaction between the MOF and the targets, and Eu-MOF displays preeminent anti-interference ability for sensing targets in complicated environments. The obvious emission changes achieved visible detection by naked eye under UV light.

荧光金属有机框架（MOF）已被广泛开发为用于单目标检测的传感器矩阵。使用 MOF 进行多目标传感可以更有效、更具成本效益，但相关研究仍处于起步阶段。在这里，我们报告了新型荧光 Eu-MOF 与缺电子噻二唑官能化配体 4,4'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)dibenzoic acid (H ₂ -TTPDC) 作为有机接头，以及 Eu ³⁺离子作为金属节点用于双目标检测。由于配体的共轭结构和噻二唑活性基团，以及MOF的大孔结构，实现了乙胺和棉酚的灵敏检测，检测限分别为1.30 μM和4.32 μM。乙胺和 TTPDC 之间的强氢键导致扩展的 π 共轭，从而导致用 Eu-MOF 对乙胺进行荧光“开启”检测。主客体共轭引起的电子转移和增强的π-π堆积效应协同实现棉酚的“关断”传感。TTPDC 的分子内旋转结构实现的精确发射变化有助于验证 MOF 与目标之间的相互作用，Eu-MOF对复杂环境中的目标传感具有卓越的抗干扰能力。明显的发射变化实现了紫外光下肉眼可见的检测。