高精度原子力显微镜用于超顺磁性氧化铁纳米粒子的表征

Characterization of Superparamagnetic Iron Oxide Nanoparticles by Atomic Force Microscopy with High Resolution

目的：将高精度原子力显微镜用于葡聚糖包被的超顺磁性氧化铁（SPIO）纳米粒子表征,探讨它作为载体用于磁共振成像的可能性。方法：通过共沉淀法合成SPIO,分别采用透射电镜和高精度原子力显微镜对粒子进行观察。结果：透射电镜显示葡聚糖包被的SPIO核心部分即铁粒子外形主要为球形,分布比较均匀,粒径不超过5nm,不能显示葡聚糖包被后的整个粒径;而高精度原子力显微镜显示葡聚糖包被的SPIO呈立方体形,颗粒均匀,核心铁粒子直径在5nm内,葡聚糖包被后的实际粒径在20-35nm之间。结论：对于葡聚糖包被的SPIO表征检测,高精度原子力显微镜大有可为。

Objective： To determine the characterization of dextran-coated superparamagnetic iron oxide（SPIO） by atomic force microscopy（AFM） with high resolution,and evaluate the possibility for it to be used as a carrier in magnetic resonance imaging.Materials and methods： The SPIO nanoparticle was obtained by means of classical co-percipitation,and its characterization were determined by transmission electron microscopy（TEM） and AFM respectively.Results： TEM showed that the nucleus of iron oxide was mainly spherical and well dispersed,the diameter was no more than 5nm and the size of the coated particles could not be revealed.But the AFM suggested that the dextran-coated SPIO was cubic and had good dispersion,the diameter of nucleus was less than 5nm,and the coated particle was 20～35nm in size.Conclusions： To detect the characterization of dextran-coated SPIO,the AFM is promising.