title: A facile synthesis of small-sized, highly photoluminescent, and monodisperse CdSeS QD/SiO(2) for live cell imaging.
abstract: In recent years, silica coating has been extensively investigated to fabricate the biocompatible interface of quantum dots (QDs) for biomedical applications. We here describe a facile and efficient method of synthesizing high-quality silica-coated CdSeS QDs (CdSeS QD/SiO(2)), where an immediate photoluminescence-favorable microenvironment is first created by assembling amphiphilic molecules around the CdSeS core, and a thin silica shell is further introduced to protect this hydrophobic interlayer. The prepared CdSeS QD/SiO(2) exhibits excellent properties such as good water solubility, low cytotoxicity, and high quantum yield (QY, up to 0.49) as well as the resistance of photobleaching in aqueous solution. Also, the CdSeS QD/SiO(2) nanoparticles homogeneously comprise single CdSeS cores and hold a comparatively small size up to about 11 nm in diameter. Particularly, this method leads to a significant increase in QY as compared to the uncoated CdSeS QDs ( approximately 109% of the initial QY), though only thin silica shells formed in the CdSeS QD/SiO(2) structure. By coupling with folic acids, the CdSeS QD/SiO(2) conjugates were successfully used for tumor cell labeling. Our results demonstrated a robust hydrophobic QDs-based approach for preparing highly photoluminescent, biocompatible QD/SiO(2) through creation of a stable hydrophobic interlayer surrounding the QD cores, which could be also suitable for silica coating of other kinds of hydrophobic nanoparticles.
authors.affiliation: Single-molecule and Nanobiology Laboratory, Department of Biophysics, School of Basic Medical Sciences and Biomed-X Center, Peking University, Beijing 100191, China.
authors.forename: Rongcheng
authors.initials: R
authors.lastname: Han
authors.forename: Min
authors.initials: M
authors.lastname: Yu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zheng
authors.forename: Lijun
authors.initials: L
authors.lastname: Wang
authors.forename: Yuankai
authors.initials: Y
authors.lastname: Hong
authors.forename: Yinlin
authors.initials: Y
authors.lastname: Sha
mesh_terms: D000042:Absorption; D000818:Animals; D002470:Cell Survival; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D049408:Luminescent Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D057054:Molecular Imaging / Q000379:methods*; D010316:Particle Size; D038761:Photobleaching; D045663:Quantum Dots; D018036:Selenium Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D012822:Silicon Dioxide / Q000737:chemistry*; D013194:Staining and Labeling; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D049408:Luminescent Agents; D018036:Selenium Compounds; D012822:Silicon Dioxide