title: Small GSH-Capped CuInS2 Quantum Dots: MPA-Assisted Aqueous Phase Transfer and Bioimaging Applications.
abstract: An efficient ligand exchange strategy for aqueous phase transfer of hydrophobic CuInS2/ZnS quantum dots was developed by employing glutathione (GSH) and mercaptopropionic acid (MPA) as the ligands. The whole process takes less than 20 min and can be scaled up to gram amount. The material characterizations show that the final aqueous soluble samples are solely capped with GSH on the surface. Importantly, these GSH-capped CuInS2/ZnS quantum dots have small size (hydrodynamic diameter <10 nm), moderate fluorescent properties (up to 34%) as well as high stability in aqueous solutions (stable for more than three months in 4 °C without any significant fluorescence quenching). Moreover, this ligand exchange strategy is also versatile for the aqueous phase transfer of other hydrophobic quantum dots, for instance, CuInSe2 and CdSe/ZnS quantum dots. We further demonstrated that GSH-capped quantum dots could be suitable fluorescence markers to penetrate cell membrane and image the cells. In addition, the GSH-capped CuInS2 quantum dots also have potential use in other fields such as photocatalysis and quantum dots sensitized solar cells.
authors.forename: Chuanzhen
authors.initials: C
authors.lastname: Zhao
authors.forename: Zelong
authors.initials: Z
authors.lastname: Bai
authors.affiliation: ‡Cancer Research Center, Sanford-Burnham Medical Research Institute, La Jolla, California 92037, United States.
authors.forename: Xiangyou
authors.initials: X
authors.lastname: Liu
authors.forename: Yijia
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: §Micro Nano Technology Center, Beijing Institute of Technology, 5 Zhongguancun South Street, Beijing 100081, P. R. China.
authors.forename: Bingsuo
authors.initials: B
authors.lastname: Zou
authors.forename: Haizheng
authors.initials: H
authors.lastname: Zhong
mesh_terms: D045744:Cell Line, Tumor; D003300:Copper / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007204:Indium / Q000737:chemistry; D018613:Microscopy, Confocal; D010316:Particle Size; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D012643:Selenium / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013440:Sulfides / Q000737:chemistry
chemical_list: D013440:Sulfides; C101793:copper indium diselenide; D007204:Indium; D003300:Copper; D005978:Glutathione; D012643:Selenium
keywords: aqueous phase transfer; glutathione; ligand exchange; quantum dots; semiconductor nanocrystals