Scaling up the Aqueous Synthesis of Visible Light Emitting Multinary AgInS2/ZnS Core/Shell Quantum Dots

Approximately 3 g of water-soluble AgInS2/ZnS core/shell quantum dots (AIS/ZnS QDs) with a maximum photoluminescence quantum yield of up to 39.1% was synthesized in an aqueous solution of gelatin and thioglycolic acid (TGA). The composition of the AIS QDs could be readily adjusted by controlling the molar ratio of the starting Ag/In precursors in the reaction solution, which leads to a tunable emission ranging from 535 to 607 nm. The as-prepared core/shell QDs exhibit excellent photostability and water/buffer stability. More importantly, these cadmium-free hydrophilic AIS/ZnS core/shell QDs are biocompatible and can be directly utilized in cancer cell imaging.