Rational Fabrication of Anionic Zinc Carboxylate Framework as Fluorescent Probe of 2,6-Pyridinedicarboxylic Acid

The sensitive, rapid and convenient sensing of 2,6-pyridinedicarboxylic acid (DPA, Bacillus anthracis biomarker) is crucial to the screen and diagnosis of anthrax. Metal organic framework (MOF) based sensors are very promising in the sensing of DPA, however the design and construction of high-performance sensors with high specificity and sensitivity is still challenging. In this work, a novel luminescent carboxylate MOF (TTCA-Zn) was assembled and employed for the specifically recognition of DPA. It is found that it possesses a three-dimensional anionic framework structure of sqc topology with [NH2(CH3)2]+ as the counter ions. The fluorescence intensity of TTCA-Zn displays a “turn-on” response to the addition of DPA and can function as a high-performance fluorescent senor of DPA in a wide range of 0 to 70 μM with a low detection limit of 14 nM. The sensing mechanism is also systematically investigated. This work not only reports a new fluorescent sensing material for DPA, but also provides a strategy for the structural design, assembly, and application of such sensors.