Janus nanofiber: a new strategy to achieve simultaneous enhanced magnetic-photoluminescent bifunction

Magnetic-photoluminescent bifunctional Janus nanofibers have been successfully fabricated by electrospinning technology using a homemade parallel spinneret. NaYF₄:Eu³⁺ and Fe₃O₄ nanoparticles (NPs) were respectively incorporated into polyvinyl pyrrolidone (PVP) and eleactrospun into Janus nanofibers with NaYF₄:Eu³⁺/PVP as one strand nanofiber and Fe₃O₄/PVP as another strand nanofiber. The morphologies, structures, magnetic and photoluminescent properties of the as-prepared samples were investigated in detail by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, energy dispersive spectrometry, vibrating sample magnetometry and fluorescence spectroscopy. The results show Janus nanofibers simultaneously possess superior magnetic and luminescent properties due to their special structure, and the luminescent characteristics and saturation magnetizations of the Janus nanofibers can be tuned by adding various amounts of NaYF₄:Eu³⁺ NPs and Fe₃O₄ NPs. Compared with Fe₃O₄/NaYF₄:Eu³⁺/PVP composite nanofibers, the magnetic-photoluminescent bifunctional Janus nanofibers provide better performances due to isolating NaYF₄:Eu³⁺ NPs from Fe₃O₄ NPs. The novel magnetic-photoluminescent bifunctional Janus nanofibers have potential applications in the fields of new nano-bio-label materials, drug target delivery materials and future nanodevices owing to their excellent magnetic and luminescent performance. More importantly, the design conception and construction technology are of universal significance to fabricate other bifunctional Janus nanofibers.