A highly sensitive resonance light scattering probe for Alzheimer's amyloid-β peptide based on Fe3O4@Au composites

Talanta. 2015 Jan:131:475-9. doi: 10.1016/j.talanta.2014.07.067. Epub 2014 Aug 11.

Abstract

The fabrication of Fe3O4@Au composites as a novel resonance light scattering (RLS) probe for the sensitive detection of Alzheimer's amyloid-β peptide (Aβ) was demonstrated. Amino groups coated magnetic Fe3O4 nanoparticles were covered with gold shell by the classical Frens method. The resultant colloids were characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS) and UV-visible spectra. The results indicated that the composite particles with core/shell structure and an average diameter of ~ 320 nm were stable and biocompatible. The RLS intensity of Fe3O4@Au composites was significantly enhanced by interacting with Aβ. Under optimal conditions, good linear relationship between the ratio of RLS intensity I/I0 at 463.0 nm and the logarithmic value of Aβ concentration in the range of 5.0 × 10(-15)-5.56 × 10(-9)M was found. The limit of detection (LOD) was 1.2 × 10(-15)M. The proposed method is simple, sensitive and cost-effective and complementary to other existing methods for protein analysis.

Keywords: Amyloid-β peptide; Core/shell; Fe(3)O(4)@Au composites; Resonance light scattering.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid beta-Peptides / analysis*
  • Ferric Compounds / chemistry*
  • Gold / chemistry*
  • Humans
  • Metal Nanoparticles / chemistry*
  • Microscopy, Electron, Transmission
  • Nanocomposites / chemistry*
  • Photoelectron Spectroscopy
  • Scattering, Radiation*
  • X-Ray Diffraction

Substances

  • Amyloid beta-Peptides
  • Ferric Compounds
  • ferric oxide
  • Gold