College of Food Science and Engineering, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China.
Food and Pharmacy College, Xuchang University, Henan, 461000, People's Republic of China.
Mikrochim Acta. 2022 Aug 10;189(9):325. doi: 10.1007/s00604-022-05438-8.
A dual-emission fluorescent (FL) probe was constructed by coordinating Cu of copper metal-organic frameworks (Cu-MOFs) with - COO group of carbon dots (CDs) for pesticide thiophanate-methyl (TM) determination. TM was recognized by organic ligands (HBDC and HBDC-NH) of Cu-MOFs via π stacking. Due to the higher affinity of Cu to TM than ligands and CDs, TM chelated with Cu to form TM-Cu complex. Thus coordination of Cu-MOFs was damaged and the ligands were released resulting in the FL intensity increase of Cu-MOFs (F). And also CDs were released from CDs@Cu-MOFs hybrids and electron transfer from CDs to CuMOFs was inhibited, leading to the FL intensity increase of CDs (F). The FL intensity ratio (F/F) showed a good linear relationship with TM concentrations of 0.0307-0.769 μmol L with a limit of detection (LOD) of ~ 3.67 nmol L. The probe was successfully applied to detect TM in spiked food samples with satisfactory recoveries of 93.1-113%. Additionally, visual detection of TM was achieved according to the fluorescence color variation from blue to carmine, indicating promising application of CDs@Cu-MOFs probe.
构建了一种双发射荧光（FL）探针，通过将铜金属-有机骨架（Cu-MOFs）中的 Cu 与碳点（CDs）的 -COO 基团配位，用于农药噻菌灵（TM）的测定。TM 通过π堆积被 Cu-MOFs 的有机配体（HBDC 和 HBDC-NH）识别。由于 Cu 与 TM 的亲和力高于配体和 CDs，因此 TM 与 Cu 螯合形成 TM-Cu 配合物。因此，Cu-MOFs 的配位被破坏，配体被释放，导致 Cu-MOFs 的 FL 强度增加（F）。而且，从 CDs@Cu-MOFs 杂化物中释放出 CDs，并且从 CDs 到 Cu-MOFs 的电子转移被抑制，导致 CDs 的 FL 强度增加（F）。FL 强度比（F/F）与 TM 浓度在 0.0307-0.769 μmol L 之间呈现出良好的线性关系，检测限（LOD）约为 3.67 nmol L。该探针成功应用于加标食品样品中 TM 的检测，回收率为 93.1-113%。此外，根据荧光颜色从蓝色到胭脂红的变化实现了 TM 的可视化检测，表明 CDs@Cu-MOFs 探针具有有前途的应用。
