自组装水热合成碳点-中空氧化硅纳米粒复合材料

利用反相微乳液体系制备出粒径均一的中空氧化硅纳米粒(SHN),以此为基础,再利用水热法通过自组装合成了碳点-中空氧化硅纳米粒复合材料(CD-SHN)。 采用高分辨透射电子显微镜(HRTEM)和场发射扫描电子显微镜(FESEM)对其结构进行了表征,结果显示SHN尺寸为30~40 nm,壳厚约为10 nm,在此基础上合成出具有和海葵类似结构的CD-SHN,尺寸约为1 μm,并且,在水相中具有良好的分散性。 海葵状CD-SHN既具有激发波长依赖的多色荧光发射性能,又具有良好的光稳定性,其最大激发及发射波长分别位于360和435 nm附近,经40 W白炽灯照射60 min,其荧光强度仍可保持97%。 该材料的制备过程条件温和,其原材料生物相容性良好,在生物造影方面具有潜在的优势。

Self-assembled Hydrothermal Synthesis of Sea Anemone-like Carbon Dot-Silica Hollow Nanocomposite

In this paper, silica hollow nanoparticles(SHNs) with quite uniform particle sizes were prepared by reverse microemulsion system. High resolution transmission electron microscopy(HRTEM) and field emission scanning electron microscopy(FESEM) were used to characterize the structure of SHNs. The carbon dots and silica hollow nanoparticles composite(CD-SHN) was prepared by hydrothermal treatment of self-assembled SHNs in presence of citric acid and ethylene diamine. FESEM images show that the average diameter of sea anemone-like carbon dots-silica nanocomposite is about 1 μm. The size of silica hollow nanosphere is between 30~40 nm, and shell thickness is 10 nm. The CD-SHN demonstrates multicolor fluorescence emission, and high photostability. The maximum excitation and emission wavelengths of CD-SHN are 360 nm and 435 nm, respectively, and 97% of the fluorescence intensity can be retained after being excited for 60 min by a 40 W incandescent lamp. Due to the mild preparation conditions and good biocompatibility of the materials, the composite material has the potential application in biological imaging.