Photoluminescent terbium-metal-organic framework and its trace bismuth-ion sensing performance

A new Tb-MOF [Tb(BDC)TDC] based on terephthalic acid (H 2 BDC) and thiophene-2,5-dicarboxylic acid (H 2 TDC) was synthesized successfully by solvothermal method . The crystal structure, morphology, thermal stability and photoluminescence properties were characterized in detail. Under the excitation of 310 ​nm, Tb-MOF presents bright green luminescence in aqueous solution. Bismuth-ion (Bi 3+ ) can quickly and specifically quench the luminescence of Tb-MOF, and the response time is only 9 ​s. The quenching mechanism is that Tb 3+ in the metal center of Tb-MOF is replaced by Bi 3+ , resulting in luminescence quenching and realizing the Bi 3+ detection. The quenching constant ( K sv ) and the detection limit for Bi 3+ are 0.024 ​μM −1 and 4.98 ​μM, respectively. The synthesized Tb-MOF can be used as the sensor for trace Bi 3+ detection in the aqueous solution.