Key Lab of Modern Precision Agriculture System Integration Research, Ministry of Education of China, China Agricultural University, Beijing 100083, China.
Key Lab of Agriculture Information Acquisition Technology, Ministry of Agriculture of China, China Agricultural University, Beijing 100083, China.
Sensors (Basel). 2020 Jan 6;20(1):312. doi: 10.3390/s20010312.
In this work, ammonium pyrrolidine dithiocarbamate (APDC) was used as a surface etchant to modify CdTe/CdS core-shell quantum dots (QDs). The APDC etchant combines with the cadmium ions (Cd) on the surface of the QDs, resulting in the formation of surface holes. The formation of these holes changes the QD surface structure, which leads to fluorescence quenching of the QDs. Newly added Cd can selectively recognize and combine with these holes; thus, the fluorescence intensity of the QDs can be restored. The linear response of this turn-on fluorescent sensor was found to be 0-100 μg/L and 100-600 μg/L under the determined optimal conditions, and its limit of detection (LOD) for Cd was 2.642 μg/L (23.5 nmol/L).
在这项工作中，使用氨 1,3-丙二硫代氨基甲酸铵（APDC）作为表面蚀刻剂来修饰 CdTe/CdS 核壳量子点（QDs）。APDC 蚀刻剂与 QDs 表面的镉离子（Cd）结合，导致表面空穴的形成。这些空穴的形成改变了 QD 表面结构，从而导致 QDs 的荧光猝灭。新添加的 Cd 可以选择性地识别和结合这些空穴，从而恢复 QDs 的荧光强度。在确定的最佳条件下，这种开启式荧光传感器的线性响应范围为 0-100μg/L 和 100-600μg/L，其 Cd 的检测限（LOD）为 2.642μg/L（23.5nmol/L）。
