3-巯基丙酸修饰的CdTe量子点荧光探针用于碘酸根离子的检测

Determination of Iodate with 3-Mercaptopropionic Acid Capped CdTe Quantum Dots as Fluorescence Probe

以3-巯基丙酸（MPA）为稳定剂，采用水相合成法制备了CdTe量子点（QDs）。基于IOf可使CdTeQDs荧光显著猝灭的特性，建立了一种检测103的荧光分析新方法。优化了实验条件，在pH=6．0、三酸缓冲溶液浓度为30mmol／L、QDs溶液浓度为8．66×10-6mol／L、反应时间为24min最佳实验条件下，检测IO-3的线性范围为6．0×10-8～7．2×10-6mol／L，检出限为4．92×10-8mol／L，方法相对标准偏差为2．37％。实验表明，IO-3对cdTeQDs的荧光猝灭有较好的选择性。方法用于自来水中IO-3的回收率实验，回收率为92．17％～103．29％。对可能的机理进行了探讨。

CdTe quantum dots（QDs） of high fluorescence was prepared in aqueous solution with 3- mercaptopropionic acid（MPA） as a stabilizer. And a new fluorometric method for the detection of iodate （IOa） was developed based on the significant fluorescence quenching of CdTe QDs. Factors affecting the IO;- detection were investigated, and the optimum conditions were determined. When pH was 6.0, the buffer concentration was 30 mmol/L, the concentration of CdTe QDs was 8. 66 × 10 6 mol/L and the reaction time was 24 min, the fluorescence sensor showed a maximum response. Under optimal conditions, its response was linearly proportional to the concentration of IOa in the range of 6.0 × 10.8 - 7.2× 10-6 mol/L with a detection limit of 4. 92 × 10 8 mol/L. The relative standard deviation for 11 replicate measurements of 1.0 × 10.6 mol/L IO/ was 2. 37%. The selectivity and interference experiments showed that the present fluorescence probe exhibited relatively high selectivity for IO-3 over other anions. The proposed method was utilized for the analysis of IO-3 in tap water and the recoveries were 92.17%-103.29% for the spiking water. The possible quenching mechanism was also discussed.