title: Preparation of Fe(3)O(4)@C@CNC multifunctional magnetic core/shell nanoparticles and their application in a signal-type flow-injection photoluminescence immunosensor.
abstract: We describe here the preparation of carbon-coated Fe3O4 magnetic nanoparticles that were further fabricated into multifunctional core/shell nanoparticles (Fe3O4@C@CNCs) through a layer-by-layer self-assembly process of carbon nanocrystals (CNCs). The nanoparticles were applied in a photoluminescence (PL) immunosensor to detect the carcinoembryonic antigen (CEA), and CEA primary antibody was immobilized onto the surface of the nanoparticles. In addition, CEA secondary antibody and glucose oxidase were covalently bonded to silica nanoparticles. After stepwise immunoreactions, the immunoreagent was injected into the PL cell using a flow-injection PL system. When glucose was injected, hydrogen peroxide was obtained because of glucose oxidase catalysis and quenched the PL of the Fe3O4@C@CNC nanoparticles. The here proposed PL immunosensor allowed us to determine CEA concentrations in the 0.005–50 ng·mL-1 concentration range, with a detection limit of 1.8 pg·mL-1.
authors.forename: Chengchao
authors.initials: C
authors.lastname: Chu
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.forename: Long
authors.initials: L
authors.lastname: Li
authors.forename: Shenguang
authors.initials: S
authors.lastname: Ge
authors.forename: Lei
authors.initials: L
authors.lastname: Ge
authors.forename: Jinghua
authors.initials: J
authors.lastname: Yu
authors.forename: Mei
authors.initials: M
authors.lastname: Yan
authors.forename: Xianrang
authors.initials: X
authors.lastname: Song
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002272:Carcinoembryonic Antigen / Q000032:analysis*; D017022:Flow Injection Analysis; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000737:chemistry*
chemical_list: D002272:Carcinoembryonic Antigen; D058185:Magnetite Nanoparticles