Nano Research

Article Title

Dual-mode protein detection based on Fe3O4-Au hybrid nanoparticles


Fe3O4, Au, electrochemical immunosensor, surface-enhanced Raman scattering


ABSTRACT A facile method of synthesizing Fe3O4–Au hybrid nanoparticles is reported utilizing the multifunctional nature of polyethyleneimine (PEI). An abundance of 5 nm gold nanoparticles were attached to 50 nm Fe3O4 nanoparticles via the covalent binding between the –NH2 groups of the PEI and Au nanoparticles, as well as the electrostatic interaction between the negatively charged citrate-coated Au nanoparticles and the positively charged PEI-coated Fe3O4 nanoparticles. The as-prepared Fe3O4–Au hybrid nanoparticles, which combine the merits of magnetic materials and gold, were successfully employed for the first time in the dual-mode detection of carcinoembryonic antigen (CEA) via electrochemical and surface-enhanced Raman scattering (SERS) methods. Both methods make clever use of Fe3O4–Au nanoparticles and can accurately verify the presence of antigens. In particular, the electrochemical immunosensor detection displays a wide linear range (0.01–10 ng/mL) of response with a low detection limit (10 pg/mL), while the SERS method responds to even lower antigen concentrations with a wider detection range. The Fe3O4–Au hybrid nanoparticles therefore exhibit great potential for biomedical applications.

Graphical Abstract


Tsinghua University Press