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 N₂H₄-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 N₂ 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-α-cyclodextrin (α-CD-SH), and per-7-thio-β-cyclodextrin (β-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 N₂H₄-containing growth solution