CdTe/CdS量子点荧光检测探针的制备及性能表征

Preparation and Characterization of CdTe/CdS Quantum Dots Fluorescent Detection Probe

优化建立简单的量子点制备方法,获得性能优良的量子点材料对于食品安全检测控制具有重要的促进意义。以巯基乙酸为稳定剂,通过水热法制备合成了核壳型CdTe/CdS量子点,采用荧光发射光谱及紫外可见光谱等对量子点的光学性能进行了评价,探究了量子点的稳定性。研究结果表明:在80℃回流,成核40 min,包壳40 min,pH=11,n(Cd^2+):n(Te^2-):n(TGA)=1:0.2:7的条件下,制备的量子点具有较优良的性能;改变上述实验条件,量子点粒径大小、尺寸分布范围以及荧光强度等都会发生不同程度的改变;稳定性研究结果表明制备的CdTe/CdS量子点随照射时间的延长,光致发光强度明显增强,量子产率也明显增加,从最初的7.80%增加到20.10%,并在第11 d达到最大。研究建立的量子点制备方法可以作为荧光探针在使用过程中根据需要调整合成条件以控制量子点大小,为食品中质量安全因子的检测提供了技术支撑,对于保障食品安全具有重要的作用。

It is important to optimize the establishment of simple quantum dots preparation method and obtain the excellent quantum dots material for food safety. The core-shell CdTe/CdS quantum dots were prepared by hydrothermal method using thioglycolic acid as stabilizer. The optical properties of quantum dots were evaluated by fluorescence emission spectroscopy and UV-Vis spectra. Then, the stability of quantum dots was investigated. The results showed that the quantum dots with excellent performance were prepared under the conditions of 80 ℃ reflux, nucleation 40 min, cladding 40 min, pH=11, n(Cd2+) : n(Te2-):n(TGA)=1:0.2:7. Quantum particle size, size distribution range and fluorescence intensity varied with the change of above experimental conditions. The results of the stability study showed that the photoluminescence intensity of the prepared Cd Te/Cd S quantum dots increased with the irradiation time, and the quantum yield increased significantly from the 7.80% to 20.10% and reached the maximum at 11 th day. The research and establishment of the preparation method can be used as a fluorescent probe to adjust the synthesis conditions according to the needs to control the size of the quantum dots and provide technical support for the detection of quality safety factors in food, which can play an important role in ensuring food safety.