Preparation of superparamagnetic β-cyclodextrin-functionalized composite nanoparticles with core-shell structures

In this article, we report an original and feasible protocol for the preparation of superparamagnetic β-cyclodextrin-functionalized composite nanoparticles with core-shell structures via cross linking reaction on the surface of carboxymethyl β-cyclodextrin-modified magnetite (Fe ₃O₄) nanoparticles by using epichlorohydrin as a crosslinking agent. The structure and morphology of the prepared composite nanoparticles were studied by Fourier transform infrared spectrometry, X-ray diffraction measurement, transmission electron microscopy and the thermogravimetric analysis. The results show that the prepared roughly spherical composite nanoparticles (diameter about 10-20 nm) with core-shell structures turned out to be magnetite nanoparticles surface-surrounded by a layer of cross-linked CM-β-cyclodextrin polymer. Results of vibrating sample magnetometry testing and inclusive behaviour studying confirmed the superparamagnetism with saturation magnetization value of 52.0 emu/g in an external applied magnetic field of 20000 Oe and inclusion functionality of the composite nanoparticles consisting of magnetite cores and β-cyclodextrin moiety, which implies very important applications in targeting drug delivery technology and separation for specific substances.