Le Anh-Tuan, Giang Chu Duy, Tam Le Thi, Tuan Ta Quoc, Phan Vu Ngoc, Alonso Javier, Devkota Jagannath, Garaio Eneko, García José Ángel, Martín-Rodríguez Rosa, Fdez-Gubieda Ma Luisa, Srikanth Hariharan, Phan Manh-Huong
Department of Nanoscience and Nanotechnology-DoNST, Advanced Institute for Science and Technology (AIST), Hanoi University of Science and Technology (HUST), 01 Dai Co Viet Street, Hai Ba Trung District, Hanoi 10000, Vietnam.
Nanotechnology. 2016 Apr 15;27(15):155707. doi: 10.1088/0957-4484/27/15/155707. Epub 2016 Mar 2.
A promising nanocomposite material composed of MnFe2O4 (MFO) nanoparticles of ∼17 nm diameter deposited onto graphene oxide (GO) nanosheets was successfully synthesized using a modified co-precipitation method. X-ray diffraction, transmission electron microscopy, and selected area electron diffraction confirmed the quality of the synthesized samples. Fourier transform infrared measurements and analysis evidenced that the MFO nanoparticles were attached to the GO surface. Magnetic measurements and analysis using the modified Langevin model evidenced the superparamagnetic characteristic of both the bare MFO nanoparticles and the MFO-GO nanocomposite at room temperature, and an appreciable increase of the effective anisotropy for the MFO-GO sample. Magnetic hyperthermia experiments performed by both calorimetric and ac magnetometry methods indicated that relative to the bare MFO nanoparticles, the heating efficiency of the MFO-GO nanocomposite was similar at low ac fields (0-300 Oe) but became progressively larger with increasing ac fields (>300 Oe). This has been related to the higher effective anisotropy of the MFO-GO nanocomposite. In comparison with the bare MFO nanoparticles, a smaller reduction in the heating efficiency was observed in the MFO-GO composites when embedded in agar or when their concentration was increased, indicating that the GO helped minimize the physical rotation and aggregation of the MFO nanoparticles. These findings can be of practical importance in exploiting this type of nanocomposite for advanced hyperthermia. Magnetoimpedance-based biodetection studies also indicated that the MFO-GO nanocomposite could be used as a promising magnetic biomarker in biosensing applications.
采用改进的共沉淀法成功合成了一种有前景的纳米复合材料，该材料由直径约17 nm的MnFe2O4（MFO）纳米颗粒沉积在氧化石墨烯（GO）纳米片上组成。X射线衍射、透射电子显微镜和选区电子衍射证实了合成样品的质量。傅里叶变换红外测量和分析表明MFO纳米颗粒附着在GO表面。使用改进的朗之万模型进行的磁性测量和分析表明，在室温下，裸露的MFO纳米颗粒和MFO-GO纳米复合材料均具有超顺磁性，并且MFO-GO样品的有效各向异性有明显增加。通过量热法和交流磁强计法进行的磁热疗实验表明，相对于裸露的MFO纳米颗粒，MFO-GO纳米复合材料在低交流磁场（0 - 300 Oe）下的加热效率相似，但随着交流磁场增加（>300 Oe）逐渐变大。这与MFO-GO纳米复合材料较高的有效各向异性有关。与裸露的MFO纳米颗粒相比，当MFO-GO复合材料嵌入琼脂中或其浓度增加时，加热效率的降低较小，这表明GO有助于使MFO纳米颗粒的物理旋转和聚集最小化。这些发现对于开发这种类型的纳米复合材料用于先进的热疗可能具有实际重要性。基于磁阻抗的生物检测研究还表明，MFO-GO纳米复合材料在生物传感应用中可作为一种有前景的磁性生物标志物。
