title: Goat anti-rabbit IgG conjugated fluorescent dye-doped silica nanoparticles for human breast carcinoma cell recognition.
abstract: We report an indirect method for cancer cell recognition using photostable fluorescent silica nanoprobes as biological labels. The dye-doped fluorescent silica nanoparticles were synthesized using the water-in-oil (W/O) reverse microemulsion method. The silica matrix was produced by the controlled hydrolysis of tetraethylorthosilicate (TEOS) in water nanodroplets with the initiation of ammonia (NH3·H2O). Fluorescein isothiocyanate (FITC) or rhodamine B isothiocyanate conjugated with dextran (RBITC-Dextran) was doped in silica nanoparticles (NPs) with a size of 60 ± 5 nm as a fluorescent signal element by covalent bonding and steric hindrance, respectively. The secondary antibody, goat anti-rabbit IgG, was conjugated on the surface of the PEG-terminated modified FITC-doped or RBITC-Dextran-doped silica nanoparticles (PFSiNPs or PBSiNPs) by covalent binding to the PEG linkers using the cyanogen bromide method. The concentrations of goat anti-rabbit IgG covering the nanoprobes were quantified via the Bradford method. In the proof-of-concept experiment, an epithelial cell adhesion molecule (EpCAM) on the human breast cancer SK-Br-3 cell surface was used as the tumor marker, and the nanoparticle functionalized with rabbit anti-EpCAM antibody was employed as the nanoprobe for cancer cell recognition. Compared with fluorescent dye labeled IgG (FITC-IgG and RBITC-IgG), the designed nanoprobes display dramatically increased stability of fluorescence as well as photostability under continuous irradiation.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan Institute of Biotechnology, and State Key Laboratory of Virology, Wuhan University, Wuhan, 430072, P.R. China. hwtang@whu.edu.cn.
authors.forename: Min-Yan
authors.initials: MY
authors.lastname: Chen
authors.forename: Ze-Zhong
authors.initials: ZZ
authors.lastname: Chen
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Wu
authors.forename: Hong-Wu
authors.initials: HW
authors.lastname: Tang
authors.forename: Dai-Wen
authors.initials: DW
authors.lastname: Pang
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000473:pathology*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006041:Goats; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D007074:Immunoglobulin G; D012822:Silicon Dioxide