Fe3O4＠SiO2磁性荧光双功能纳米粒的制备及其表征

为了制备同时具备磁性和荧光性的双功能纳米粒,采用有机模板和反相微乳液相结合的方法,将Fe3O4磁性纳米粒包裹在二氧化硅(SiO2)中,形成核壳结构,然后通过3-氨丙基三乙氧基硅烷(APTES)的中介作用,连上异硫氰酸荧光素(FITC),生成Fe3O4@SiO2(FITC)纳米粒。为了进行磁性分离的实验,制备连有罗丹明B异硫氰酸(RITC)的SiO2纳米粒[SiO2(RITC)]作为对照品。采用傅里叶红外、X线衍射、透射电镜和振动样品磁强计(VSM)对Fe3O4@SiO2(FITC)纳米粒的形貌和性质进行表征。结果得到了粒径为100 nm左右,饱和磁化强度为29.8 emu/g,具有超顺磁性和荧光性的纳米粒;荧光显微镜观察结果表明,Fe3O4@SiO2(FITC)在磁性分离应用中的效果良好。

Synthesis and characterization of Fe3O4@SiO2 magnetic-fluorescent bifunctional nanoparticles

Fe3O4@SiO2 nanoparticles were prepared by way of combining organic template and reverse micro-emulsion,and Fe3O4 nanoparticles were covered by silica layers with core-shell morphologies.Then fluorescein 5-isothiocyanate(FITC) was chemically attached onto the nanoparticles by 3-aminopropyl-triethoxysilane(APTES),realizing Fe3O4@SiO2(FITC) nanoparticles with the dual functions of the magnetic and fluorescence.We prepared SiO2(RITC) nanoparticles incorporating covalently with rhodamine B isothiocyanate(RITC) as control for magnetic separation experiments.The Fe3O4@SiO2(FITC) nanoparticles were then characterized by Fourier transform infrared(FT-IR) spectrometry,X-ray diffraction(XRD),transmission electron microscopy(TEM) and vibrating sample magnetometer(VSM) techniques.Results showed that the average diameter of nanoparticles was about 100 nm,and the saturation magnetization was 29.8 emu/g,which exhibited superparamagnetic behavior and high fluorescent intensity.The fluorescent microscopic observations showed that Fe3O4@SiO2(FITC) had both magnetic and fluorescent properties with a good separation effect.