Seed-mediated growth approach for rapid synthesis of high-performance red-emitting CdTe quantum dots in aqueous phase and their application in detection of highly reactive oxygen species

Here we demonstrate the seed-mediated growth approach, one of the most reliable and versatile methods to control the size and shape of nanocrystals (NCs), for rapid synthesis of high performance red-emitting core/shell CdTe quantum dots (QDs) in aqueous phase. Critical parameters (including the pH value, Cd:Te molar ratio, MPA:Cd molar ratio, and the amount of CdTe seeds) affecting the growth of core/shell CdTe QDs are systematically introduced and analyzed. Under optimal conditions, the growth behaviors can be well controlled, and the high performance typically offered by the seed-mediated growth method was obtained as expected. The emission peak position quickly shifted from 540 to 680 nm in 30 min, and the red-emitting CdTe QDs thus obtained performed well, giving good size distribution, narrow full width at half maximum and high quantum yield. The growth mechanism and the resulting high structural and optical properties were also elucidated. Finally, the obtained CdTe QDs were successfully applied to highly reactive oxygen species (hROS) sensing, suggesting that this method may be useful in bioimaging and biolabeling.