Luminomagnetic Silica-Coated Heterodimers of CoreShell FePtFe3O4 and CdSe Quantum Dots as Potential Biomedical Sensor

Abstract EN

We report the synthesis of a new multifunctional nanomaterial based on silica-coated FePt/Fe3O4-CdSe heteronanostructures, combining luminescent and magnetic properties in a promising bifunctional sensor for biomedical applications.

Spherical Fe3O4-coated FePt (FePt/Fe3O4) superparamagnetic nanoparticles (10.8 ± 1.5 nm) with high saturation magnetization and controlled size and shape were obtained using thermal decomposition coupled with seed-mediated growth method.

Luminescent property was added to the nanomaterial by using the FePt/Fe3O4 magnetic core as seed and growing the CdSe quantum dots (2.7 ± 0.6 nm) onto its surface in a heterodimer-like structure using the hot-injection approach.

The FePt/Fe3O4-CdSe luminomagnetic heteronanostructures were coated with silica shell using the reverse-micelle microemulsion route to avoid solvent-quenching effects.

After silica coating, the water-dispersible heteronanostructures showed a diameter of 25.3 ± 2 nm, high colloidal stability, magnetic saturation of around 11 emu g−1, and photoluminescence in the blue-green region, as expected for potential bifunctional platform in biomedical applications.

The saturation magnetization of heteronanostructures can be increased to 28 emu g−1 by annealing at 550°C due to the presence of the FePt phase.