Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
Anal Chem. 2020 May 19;92(10):7114-7122. doi: 10.1021/acs.analchem.0c00499. Epub 2020 May 1.
Monitoring and early warning of spores germination is of great significance in avoiding their potential pathogenicity. Thus, effective monitoring of markers during spore germination is of great value. A ratio-dependent fluorescent probe based on in situ incorporation of fluorophores in a metal-organic framework (MOF) was designed to monitor a main component of bacterial spores, 2,6-pyridinedicarboxylic acid (DPA), with high sensitivity and specificity. The fluorescence of CdS quantum dots loaded on zeolitic imidazolate framework-8 (ZIF-8) nanocrystals is initially quenched by europium ions. The europium ions, however, can be seized by DPA, leading to restoring the fluorescence of quantum dots. Simultaneously, the fluorescence of another dye molecule, rhodamine 6G, loaded on the ZIF-8 is not affected by DPA and can serve as a stable internal fluorescence reference signal. On this basis, a ratio-dependent fluorescence method for rapid detection of DPA was established. The linear calibration ranged from 0.1 to 150 μM with a detection limit of 67 nM, which is much lower than the amount of DPA (60 μM) released by the contagious number of spores needed to cause anthrax. This analysis platform exhibits good anti-interference ability for monitoring spore germination. The practicable application of the method was verified by monitoring and imaging the release of DPA in the course of spore germination.
监测和预警孢子萌发对于避免其潜在致病性具有重要意义。因此，在孢子萌发过程中有效监测标记物具有重要价值。本研究设计了一种基于金属-有机框架（MOF）原位掺入荧光团的比率依赖性荧光探针，用于高灵敏度和特异性地监测细菌孢子的主要成分 2,6-吡啶二甲酸（DPA）。负载在沸石咪唑酯骨架-8（ZIF-8）纳米晶体上的硫化镉量子点的荧光最初被铕离子猝灭。然而，铕离子可以被 DPA 捕获，从而恢复量子点的荧光。同时，负载在 ZIF-8 上的另一种染料分子罗丹明 6G 的荧光不受 DPA 的影响，可以作为稳定的内部荧光参考信号。在此基础上，建立了一种用于快速检测 DPA 的比率依赖性荧光方法。线性校准范围为 0.1-150 μM，检测限为 67 nM，远低于炭疽病所需传染性孢子数量释放的 DPA 量（60 μM）。该分析平台在监测和成像孢子萌发过程中 DPA 的释放方面表现出良好的抗干扰能力。通过监测和成像孢子萌发过程中 DPA 的释放，验证了该方法的实际应用。
