title: Synthesis and characterization of core-shell Au Fe oxide nanocomposites and their application for detecting immunological interaction.
abstract: Gold (Au) Fe oxide core-shell nanostructure is a major class of nanoscale materials that has attracted considerable attention due to its biotechnological and biomedical applications and properties. Here we synthesized magnetite nanoparticles (MNPs), an average size of 10-12 nm in diameter, using the chemical co-precipitation of Fe2(+) and Fe3(+) in strong alkaline material. Then, an Au-coated Fe oxide core-shell nanocomposite with an average diameter of 18-20 nm was produced in the presence of sodium citrate as the reducing agent. The core-shell structure and the presence of the Fe and Au phases have been confirmed by transmission electron microscopy (TEM), x-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The Au-coated Fe oxide NPs can be used as a carrier in digoxin immunoassays. The concentration of anti-digoxin antibody (Ab) immobilized on the NPs was 30 μg/mg. In order to validate the quality of the Au-coated Fe oxide NPs as immunoassay carriers, an immunoassay system was developed. The relative amount of anti-digoxin Ab immobilized on the NPs was determined by enzyme linked immunosorbent assay (ELISA). Immobilization studies with Ab demonstrated that the Au Fe oxide core-shell nanostructure can be used to immobilize Ab, making them valuable for biomedical and biological applications.
authors.affiliation: 1 Biosensor Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences , Tehran, Iran .
authors.forename: Anita
authors.initials: A
authors.lastname: Ahmadi
authors.forename: Hanieh
authors.initials: H
authors.lastname: Shirazi
authors.forename: Narges
authors.initials: N
authors.lastname: Pourbagher
authors.forename: Kobra
authors.initials: K
authors.lastname: Omidfar
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry*; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D004077:Digoxin / Q000276:immunology; D005290:Ferric Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D055910:Antibodies, Immobilized; D000911:Antibodies, Monoclonal; D005290:Ferric Compounds; C000499:ferric oxide; D004077:Digoxin; D006046:Gold