Synthesis of CS-Fe3O4@ZnSe:Mn/ZnS magnetic and fluorescent biofunctional nanoparticles by electrostatic interaction approach

Magnetic and fluorescent biofunctional nanoparticles (MFNPs) CS-Fe3O4@ZnSe:Mn/ZnS were synthesized through electrostatic interaction technique. Firstly, chitosan coated Fe3O4 magnetic nanoparticles (CS-Fe3O4 MPs) were prepared by co-precipitation of ferrous and ferric ions in chitosan solution. Secondly, ZnSe:Mn/ZnS doped quantum dots (d-dots) were prepared by hydrothermal method using 3-mercaptopropionic acid (MPA) as a stabilizer. At last, the obtained CS-Fe3O4 MPs and ZnSe:Mn/ZnS d-dots were incorporated into a chitosan matrix. The structure and properties of the as-synthesized CS-Fe3O4@ZnSe:Mn/ZnS MFNPs were fully characterized. It was found that the MFNPs exhibit superparamagnetic and strong photoluminescence properties, favorable for their applications in simultaneous biolabeling, dual-modality imaging and selective magnetic separation. This work provide theoretical basis for the preparation of functional nanoparticles.