In the present work, we have developed a rapid, cost-effective aqueous phase route to synthesize water-soluble Thioglycolic acid (TGA) capped CdSe/ZnS (CdSe/ZnS + TGA) QD sensor. Synthesized QD sensor has been successfully validated its candidature for the efficient detection of hazardous heavy metal ions (Xⁿ⁺) specifically chromium (Cr³⁺) and copper (Cu²⁺) in aqueous medium. In the presence of Xⁿ⁺ metal ions, ‘‘Turn-Off’’ fluorescence response is observed due to the complex formation (Xⁿ⁺: CdSe/ZnS + TGA). A strong 1:1 complexation (Xⁿ⁺: CdSe/ZnS + TGA) between QD sensor and Xⁿ⁺ metal ion is confirmed by the output of Benesi–Hildebrand relation and Job’s plot. As per our knowledge our proposed CdSe/ZnS + TGA QD sensor has established its efficient sensing capability for metal ions with lower detection of limit (LOD) up to concentration ~ 10^–7 M for the first time which is lower than permissible limit as per WHO data. The practical application of this system for determining metal ions in real samples has also been successfully demonstrated.

Graphical Abstract

中文翻译：

---

巯基乙酸封端的CdSe/ZnS量子点作为荧光传感器用于检测水溶性有害重金属离子

在目前的工作中，我们开发了一种快速、经济有效的水相路线来合成水溶性硫代乙醇酸（TGA）封端的CdSe/ZnS（CdSe/ZnS + TGA）QD传感器。合成的 QD 传感器已成功验证其作为有效检测水介质中有害重金属离子 ( X ^{n +} ) 特别是铬 (Cr ³⁺ ) 和铜 (Cu ²⁺ ) 的候选资格。当存在X ^{n +金属离子时，由于络合物的形成（} X ^{n +} : CdSe/ZnS + TGA），观察到“关闭”荧光响应。 Benesi-Hildebrand 关系和乔布图的输出证实了QD 传感器和X ^{n +}金属离子之间的强 1:1 络合（X ^{n +} : CdSe/ZnS + TGA）。据我们所知，我们提出的 CdSe/ZnS + TGA QD 传感器 首次建立了对金属离子的高效传感能力，检测限 (LOD) 浓度高达 ~ 10 ^–7 M，低于允许的限值世界卫生组织数据。该系统在实际样品中测定金属离子的实际应用也已得到成功证明。

图形概要