A Ln-MOF Sensor Based on Dual-Signal Response and Logic Gating for the Ratio Fluorescence Detection of Anthrax Biomarkers.

Anthrax is an acute infectious disease caused by Bacillus anthracis. It can damage the skin, lungs, and intestines of humans and animals and can be fatal in severe cases. Therefore, it is of great significance to develop highly efficient detection methods. Pyridine-2,6-dicarboxylic acid (DPA), a major component of bacterial spores, can be used as a biomarker for the detection of anthrax. However, existing biological and chemical detection methods have shortcomings. Biological methods often involve lengthy procedures, complex equipment, and expensive reagents. In chemical methods, most fluorescence sensors for DPA detection have low sensitivity, precision, and accuracy. To solve this, a dual-signal-responsive ratiometric fluorescence sensor was designed. First, Bio-MOF was synthesized with Zn2+, adenine, and 1,3,5-benzenetricarboxylic acid. Then, Tb3+ was introduced via cation exchange, and 1-Hydroxypyrene (1-OHP) was introduced via hydrogen bonds to get 1-OHP/Tb@Bio-MOF. With DPA, Tb3+ forms a complex, enhancing its emission ("turn-on"), while DPA reduces 1-OHP emission ("turn-off") via IFE and PET. This sensor detects DPA in serum sensitively and selectively, and a DPA-monitoring logic gate was made. Also, a paper-based sensor (1-OHP/Tb-MOF@CP) was prepared by blending.