Self-Assembled Au@Fe Core/Satellite Magnetic Nanoparticles for Versatile Biomolecule Functionalization

Although the functionalization of magnetic nanoparticles (MNPs) with biomolecules has been widely explored for various biological applications, achieving efficient bioconjugations with a wide range of biomolecules through a single, universal, and versatile platform remains a challenge, which may significantly impact their applications’ outcomes. Here, we report a novel MNP platform composed of Au@Fe core/satellite nanoparticles (CSNPs) for versatile and efficient bioconjugations. The engineering of the CSNPs is facilely formed through the self-assembly of ultrasmall gold nanoparticles (AuNPs, 2–3 nm in diameter) around MNPs with a polysiloxane-containing polymer coating. The formation of the hybrid magnetic nanostructure is revealed by absorption spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), element analysis using atomic absorption spectroscopy, and vibrating sample magnetometer. The versatility of biomolecule loading to the CSNP is revealed through the bioconjugati...