Identification of surface-passivating ligands and core-size-dependent CdSe/CdZnS with highly emitting for cell labeling

Abstract Different organic ligands capped CdSe quantum dots (QDs) are synthesized. Our results show that CdSe QDs exhibit high photoluminescent intensity when the surface dangling bonds are passivated by trioctylphosphine and oleylamine together. FT-IR vibrational spectra reveal that the oleylamine mainly bond to the metal sites. In the process of synthesis, oleylamine can make CdSe more uniform by controlling the rate of nucleation and growth. Because of size-dependent band gap, core/shell QDs emitting desired color can be obtained by coating different sized cores. The photoluminescence peaks of core/shell QDs cover a wide range from 580 to 615 nm. The core/shell QDs are successfully transferred into aqueous solution through ligand exchanging with reduced glutathione and used to label HeLa cells.