College of Chemical Engineering , Zhejiang University of Technology , Hangzhou 310014 , China.
Departments of Chemical and Petroleum Engineering , University of Wyoming , Laramie , Wyoming 82071 , United States.
J Agric Food Chem. 2018 Jun 27;66(25):6431-6438. doi: 10.1021/acs.jafc.8b00662. Epub 2018 Jun 14.
Future food safety monitoring with simple, fast, and visual methods has become increasingly important. Accordingly, this work was designed to construct a new-style dual-emission ratiometric fluorescent probe (CdSe@SiO@CdTe) for visual assay of glutathione (GSH) with a "turn on" strategy. After adding Hg, the red fluorescence of the outer CdTe quantum dots (QDs) was quenched through both electron transfer and ion-binding processes. Upon the addition of GSH, the red fluorescence occurred again owing to the strong affinity between GSH and Hg, whereas the inner green fluorescence of CdSe QDs was unchanged, leading to a clearly recognizable fluorescence color change (from green to orange-red). In the concentration range from 0.1 to 10 μM, the relative fluorescence intensity ratios ( I/ I) showed an excellent linear correlation with the concentration of GSH, and the detection limit was as low as 42 nM under optimal conditions. Meanwhile, the ratiometric hybrid probes were successfully applied for direct visual sensing GSH in real vegetable and fruit samples.
未来的食品安全监测越来越需要简单、快速、可视化的方法。因此，本工作设计了一种新型的双发射比率荧光探针（CdSe@SiO@CdTe），用于可视化检测谷胱甘肽（GSH），采用“开启”策略。加入 Hg 后，通过电子转移和离子结合过程，外层 CdTe 量子点（QDs）的红色荧光被猝灭。加入 GSH 后，由于 GSH 和 Hg 之间的强亲和力，红色荧光再次出现，而 CdSe QDs 的内绿光荧光保持不变，导致荧光颜色发生明显可识别的变化（从绿色变为橙红色）。在 0.1 至 10 μM 的浓度范围内，相对荧光强度比（ I/ I）与 GSH 的浓度呈现出极好的线性关系，在最佳条件下检测限低至 42 nM。同时，比率混合探针成功应用于直接可视化检测真实蔬菜和水果样品中的 GSH。
