title: Polyvalent lactose-quantum dot conjugate for fluorescent labeling of live leukocytes.
abstract: Oligosaccharides play crucial roles in many biorecognition processes by the so-called "cluster glycosidic effect". We here report a facile synthesis of lactose-CdSeS/ZnS quantum dot conjugate (Lac-QDs) by use of 1-thiol-beta-D-lactose via ligand exchange, which exhibits significantly high affinity and specificity to leukocytes in contrast to the monovalent lactose. Structural analyses indicate that there are about 132 lactosyl molecules assembled on single QDs and the hydrodynamic diameter is small, close to 8.2 nm. Further, Lac-QDs display good fluorescence and physicochemical stability in physiological conditions, as well as extremely low cytotoxicity. These properties facilitate the use of Lac-QDs in fluorescent labeling of live leukocytes.
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: Min
authors.initials: M
authors.lastname: Yu
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Rongcheng
authors.initials: R
authors.lastname: Han
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: Zhongjun
authors.initials: Z
authors.lastname: Li
authors.forename: Yinlin
authors.initials: Y
authors.lastname: Sha
mesh_terms: D005456:Fluorescent Dyes / Q000737:chemistry*; D005978:Glutathione / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007785:Lactose / Q000737:chemistry*; D007962:Leukocytes / Q000737:chemistry*; D045663:Quantum Dots; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D005456:Fluorescent Dyes; D005978:Glutathione; D007785:Lactose