Tunable and enhanced simultaneous magnetism-luminescence bifunctionality assembled into a coaxial nanofiber

Abstract

[CoFe₂O₄–PVP]@[(Y(NO₃)₃ + Tb(NO₃)₃ + Al(NO₃)₃)–PVP] composite coaxial nanofibers have been successfully fabricated via electrospinning technology using a homemade coaxial spinneret. A new structure of CoFe₂O₄@YAG:Tb³⁺ magnetic-luminescent bifunctional coaxial nanofibers is obtained by calcination of the prepared electrospun composite coaxial nanofibers. The morphologies, structures, magnetic and luminescence properties of the final products were investigated in detail by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), fluorescence spectroscopy and vibrating sample magnetometry (VSM). The results show that the CoFe₂O₄@YAG:7%Tb³⁺ magnetic-luminescent bifunctional coaxial nanofibers simultaneously possess superior magnetic and luminescence properties due to isolation of the YAG:7%Tb³⁺ luminescence center from CoFe₂O₄ magnetic nanofibers. Furthermore, the luminescence intensity, color and saturation magnetization of the coaxial nanofibers can be tuned via adjusting the concentrations of rare earth ions and the amount of CoFe₂O₄ magnetic nanofibers. The bifunctional magnetic-luminescent CoFe₂O₄@YAG:7%Tb³⁺ coaxial nanofibers have potential applications in biomedical areas, such as drug-delivery systems, cell labeling and separation, enhancement for magnetic resonance imaging and subsequent optical identification. More importantly, the design conception and construction technology can fit the elaboration of any other bifunctional coaxial nanofibers.