College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, 310014, PR China.
College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, 310014, PR China.
Talanta. 2020 Dec 1;220:121377. doi: 10.1016/j.talanta.2020.121377. Epub 2020 Jul 12.
We reported Eu(III) functionalized carbon dots (CDs-Eu) as a novel ratiometric fluorescent probe for point-of-care testing (POCT) of dipicolinic acid (DPA), a biomarker of anthrax. The probe was synthesized simply by coordination interaction between Eu(III) ions and the CDs with carboxyl and amino groups. Upon addition of DPA, the intrinsic red luminescence of Eu(III) ions can be sensitized due to the presence of energy transfer when DPA chromophore coordinated with Eu(III) ions. The fluorescence peaking at 530 nm as a reference remained essentially constant, leading to ratiometric fluorescence response toward DPA. This approach exhibited a linearity range from 0.5 nM to 5 μM and a detection limit of 0.8 nM. More Importantly, the combination of probe-based test paper and smartphone provided a convenient approach for visual POCT of DPA with a detection limit of 67 nM, which was lower than other reported test paper for DPA detection. The color of fluorescence gradually changed from green to red as the DPA increases, which can be captured by a smartphone and further quantitatively analyzed with a built-in Color Analyzer App. The satisfactory result of detecting DPA accurately and reliably in real samples by the test paper certified its practicality in POCT of DPA.
我们报道了铕（Eu（III））功能化碳点（CDs-Eu）作为一种新型比率荧光探针，用于炭疽生物标志物 - 二吡啶甲酸（DPA）的即时检测（POCT）。该探针是通过 Eu（III）离子与具有羧基和氨基的 CDs 之间的配位相互作用简单合成的。当 DPA 发色团与 Eu（III）离子配位时，由于能量转移的存在，Eu（III）离子的本征红色荧光可以被敏化。荧光在 530nm 处作为参考峰保持基本不变，导致对 DPA 的比率荧光响应。该方法表现出从 0.5 nM 到 5 μM 的线性范围和 0.8 nM 的检测限。更重要的是，探针试纸和智能手机的结合为 DPA 的目视 POCT 提供了一种便捷的方法，检测限为 67 nM，低于其他报道的 DPA 检测试纸。随着 DPA 的增加，荧光的颜色逐渐从绿色变为红色，这可以用智能手机捕捉，并进一步用内置的 Color Analyzer App 进行定量分析。试纸在真实样品中准确可靠地检测 DPA 的令人满意的结果证明了其在 DPA 的 POCT 中的实用性。
