title: Quantum dots/particle-based immunofluorescence assay: synthesis, characterization and application.
abstract: Recently, it has been proved that quantum dots (QDs) hold the potential to be used in the bioanalysis as fluorescent probes for their many unique optical properties. In this paper, immunofluorescence assay, an integration of particle-based immunoassays and fluorescent QD-probes, was constructed. Firstly, high quality CdSe/ZnS QDs were prepared. Then after being water-solubilized by amphiphilic polymer based on self-assembling, the QDs were labeled by immunoglobulin G (IgG) antibody. At the same time, both carboxyl-polystyrene (PS) and magnetic carboxyl-PS microspheres were prepared and coated by antigens. The antigen sensitized PS microspheres were specifically captured by the QD-IgG bioconjugates based on the antibody-antigen reaction, which was confirmed by the immunofluorescence test in vitro. The sensitivity of current assay was tested by sandwich immunofluorescence assay using human alpha fetoprotein (AFP) as antigen model. The detection limit of AFP antigen is 4.9 ng/mL.
authors.affiliation: Institute of Nanobiotechnology, School of Materials Science and Engineering, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin 300072, China.
authors.forename: Bingbo
authors.initials: B
authors.lastname: Zhang
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Liang
authors.forename: Lijuan
authors.initials: L
authors.lastname: Hao
authors.forename: Jing
authors.initials: J
authors.lastname: Cheng
authors.forename: Xiaoqun
authors.initials: X
authors.lastname: Gong
authors.forename: Xuhui
authors.initials: X
authors.lastname: Liu
authors.forename: Guiping
authors.initials: G
authors.lastname: Ma
authors.forename: Jin
authors.initials: J
authors.lastname: Chang
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry; D005455:Fluorescent Antibody Technique / Q000379:methods*; D057927:Hydrophobic and Hydrophilic Interactions; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D045663:Quantum Dots; D013053:Spectrophotometry
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide