Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, Southwest University, Chongqing, 400715, China.
Chongqing Key Laboratory of Translational Medicine in Major Metabolic Disease, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
Talanta. 2021 Jan 15;222:121548. doi: 10.1016/j.talanta.2020.121548. Epub 2020 Aug 26.
In this work, a novel dual-ratiometric optical probe based on europium-doped carbon dots (Eu-CDs) was developed for colorimetric and fluorescent visual sensing dipicolinic acid (DPA), a anthrax biomarker. Eu-CDs with recessive signals were prepared via thermal pyrolysis method. And the magenta appears when Eu-CDs coordinates with Eriochrome Black T (EBT). Based on the ligand displacement strategy, DPA reduces magenta and makes blue appear, which develop ratiometric colorimetric visual detection methods of DPA. Under 270 nm excitation, DPA make the red fluorescence signal of Eu in EBT-CDs@Eu appear, based on the absorbance-energy transfer-emission effect, the ratiometric fluorescent visual detection assay of DPA has been developed. Based above, dual-ratiometric optical probe was designed successfully. The limit of detection (LOD) is 10.6 nM for ratio colorimetric assay. More prominently, naked-eye determination of DPA without instrument is as low as 1.0 μM. Furthermore, its practicability was verified by quantifying the DPA in Bacillus subtilis spores and human urine (with RSD≤2.35%). The sensor shows great superiority in on-site analysis of DPA, especially in limited instruments conditions.
在这项工作中，开发了一种基于铕掺杂碳点（Eu-CDs）的新型双比率光学探针，用于比色和荧光可视化检测炭疽生物标志物——二吡啶酸（DPA）。Eu-CDs 通过热解方法制备，具有隐性信号。Eu-CDs 与 Eriochrome Black T（EBT）配位时呈现洋红色。基于配体置换策略，DPA 还原洋红色并使蓝色出现，从而开发出 DPA 的比率比色视觉检测方法。在 270nm 激发下，EBT-CDs@Eu 中的 Eu 发出红色荧光信号，基于吸收-能量转移-发射效应，开发了 DPA 的比率荧光可视化检测分析方法。在此基础上，成功设计了双比率光学探针。比率比色测定法的检测限（LOD）为 10.6nM。更突出的是，无需仪器即可通过肉眼检测到低至 1.0μM 的 DPA。此外，通过定量测定枯草芽孢杆菌孢子和人尿中的 DPA（RSD≤2.35%）验证了其实用性。该传感器在 DPA 的现场分析中表现出很大的优势，尤其是在仪器有限的情况下。
