Synthesis of a lanthanide-based bimetallic-metal-organic framework for luminescence sensing anthrax biomarker.

Lanthanide luminescence sensors have attracted extensive attention in the detection of 2, 6-pyridinedicarboxylic acid (DPA), the main biomarker of anthrax. In previous reports detecting DPA, luminescence probes may not have high selectivity and high specificity for identification. In the present study, a highly specific and sensitive luminescence probe was synthesized. In this paper, [Tb x Gd 1-x (PBA) 2 NO 3 ·2H 2 O] n is synthesized by solvothermal method using HPBA = 3.5-bis(triazol-1-yl)benzoic acid and Ln (NO 3) 3· 6H 2 O (Ln = Tb, Gd). Through modulating the molar ratio of Tb3+ ions and Gd3+ ions, the distance between Ln3+ ions is changed, leading to a change in the energy transfer from the ligand to Tb3+, which in turn leads to an increase in luminescence intensity. Meanwhile the luminous colour is regulated by the ratio of Tb/Gd, which changes from green to white as the Gd ion gradually increases. The bimetallic ratiometric luminescence sensor realized accurate, high sensitivity (LOD is 1.03 × 10−6 M) and high selectivity detection of DPA. Due to the simple synthesis method and low technical requirements, this work provides a good strategy for the development of simple and effective bimetallic ratiometric luminescence sensors. The coordination polymer (Tb 0.9 Gd 0.1 -PBA) provides specific recognition of DPA and is a fluorescent sensor with high sensitivity, high selectivity and good interference immunity. In addition the lanthanide ion doping method described in this paper allows the development of more multicentre luminescent sensing materials for the large number of available Ln-MOFs. This work will expand the application of Ln-MOFs in chemical sensing and inspire other researchers to explore in this direction. [Display omitted] • The bimetallic lanthanide coordination polymers exhibit high selectivity, fast response, DPA-specific recognition. • The bimetallic lanthanide coordination polymers have low detection limits and high sensitivity to DPA. • Luminescence sensors utilize a two-dimensional decoding map for the precise identification of DPA. • The luminescence colour can be changed by adjusting the molar ratio of Tb3+ to Gd3+. [ABSTRACT FROM AUTHOR]