Simple Synthesis of Highly Luminescent Water-Soluble CdTe Quantum Dots with Controllable Surface Functionality

Highly luminescent quantum dots (QDs) could be synthesized in conical flask now. Through a room-temperature N(2)H(4)-promoted strategy, water-soluble CdTe QDs were facilely synthesized by a stepwise addition of raw materials in one pot. No prepreparation of precursors, pH adjustment, heating, and even N(2) protection were required. Just by adjusting the feed ratio of the reagents, different-sized QDs were easily obtained within a shortened time. More importantly, besides conventional thiol-ligands, such as thioglycolic acid (TGA), 3-mercaptopropionic acid (MPA), 1-thioglycerol (TG), 2-mercaptoethylamine (MA), glutathione (GSH), and L-cysteine (LCS), some special mercapto-compounds, for instance, 4-mercaptobenzoic acid (MBA), per-6-thio-alpha-cyclodextrin (alpha-CD-SH), and per-7-thio-beta-cyclodextrin (beta-CD-SH), were also practicable, which were impossible in the conventional reflux method because of the poor water-solubility of them. Furthermore, a spontaneous aggregation of MA-stabilized QDs was observed after synthesis, which facilitated the separation of QDs and recycle of N(2)H(4)-containing growth solution.