Analytical Division, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran.
Luminescence. 2024 Sep;39(9):e4874. doi: 10.1002/bio.4874.
The capped CdS-ZnS quantum dots (QDs) were synthesized with various thiol capping agents of glycolic acid (TGA), mercaptosuccinic acid (MSA), and L-cysteine (LCY) and used as fluorescence probe for determination of Cu (II) ions. The method of two-level three-factor full-factorial experiment design was used to achieve the best optical fluorescence emission. Results revealed that Cu (II) ions can effectively quench the emission of QDs, and the fluorescence intensity is linearly decreased with increasing Cu (II) ion concentration. The limit of detection for CdS-ZnS@ QDs capped with TGA, MSA, and LCY was obtained at 1.15 × 10, 1.32 × 10, and 2.19 × 10 mol L, respectively, with linear dynamic range of 3.13 × 10 to 1.41 × 10 mol L. Luminescence quantum yields of CdS-ZnS@LCY, CdS-ZnS@MSA, and CdS-ZnS@TGA were obtained at 4.17, 1.92, and 2.47, respectively. Results indicated that no significant quenching occurred in the presence of the other metal ions. The binding constant (K) of capped CdS-ZnS@ QDs with Cu and the other metal ions was also investigated and discussed. The K value for Cu was obtained considerably more than that the other ions. This work presents a new and sensitive method for determination of Cu ion.
巯基乙酸（TGA）、巯基丁二酸（MSA）和 L-半胱氨酸（LCY）等不同硫醇配体封端的 CdS-ZnS 量子点（QDs）被合成出来，并被用作荧光探针来测定 Cu（II）离子。采用两级三因素完全实验设计方法来实现最佳的光学荧光发射。结果表明，Cu（II）离子可以有效地猝灭 QDs 的发射，并且荧光强度随着 Cu（II）离子浓度的增加呈线性降低。TGA、MSA 和 LCY 封端的 CdS-ZnS@ QDs 的检测限分别为 1.15×10、1.32×10 和 2.19×10 mol·L，线性动态范围为 3.13×10 至 1.41×10 mol·L。CdS-ZnS@LCY、CdS-ZnS@MSA 和 CdS-ZnS@TGA 的荧光量子产率分别为 4.17%、1.92%和 2.47%。结果表明，在存在其他金属离子的情况下，没有发生明显的猝灭。还研究和讨论了 CdS-ZnS@ QDs 与 Cu 和其他金属离子的结合常数（K）。Cu 的 K 值明显大于其他离子。这项工作为测定 Cu 离子提供了一种新的、灵敏的方法。
