A double emission turn-on Eu-MOF-based luminescent sensor towards an anthrax biomarker

Bacillus anthracis, an extremely dangerous bacterium which can cause pulmonary anthrax and be used as biochemical weapon agent, can be detected by the detection of its major biomarker 2, 6-pyridine dicarboxylic acid (DPA). Herein, we reported the solvothermal synthesis of a non-luminescent NH2-BDC-Eu-MOF using Eu3+ and 2-aminoterephthalic acid (NH2-BDC). The emission of amino ligand and Eu3+ ions are absent in ethanol while the addition of DPA could recover both emission at 460 and 624 nm respectively. Thus this MOF can act as a dual emission ''turn-on'' probe for DPA detection. The detection limits (LOD) of this DPA probe are about 0.8 μM in ethanol and 0.36 μM in water, which are much lower than an infectious dosage of bacillus anthracis spores (60 μM) for human being. In order to monitor DPA levels more conveniently, we developed a one-to-two decoder logic gate operation, which can determinate DPA via color discrimination.