High-quality, monodisperse, and size-controlled Fe3O4, Ag, and bifunctional Fe3O4/Ag heterodimer nanocrystals (NCs) have been synthesized successfully. In the synthesis of Fe3O4 NCs, dodecanol was chosen as the substitute of 1,2-hexadecanediol and “size control” was achieved by simply adjusting the proportion among the ligands instead of utilizing seed-mediated growth. In the synthesis of Ag NCs, organometallic silver acetylacetonate (Agacac) was used as precursors and tunable particle size could be easily obtained by adjusting the reaction temperatures. By using different sized Fe3O4 NCs as seeds, Fe3O4/Ag heterodimer NCs with particle sizes tuned from 5 to 16 nm for Fe3O4 and 4 to 8 nm for Ag were successfully synthesized and superparamagnetism were maintained. We found that the size of Ag attached on the Fe3O4 NCs relied on the size of Fe3O4 seed. UV-vis absorption spectra and TEM investigations revealed that the bigger the Fe3O4 NCs seed used, the bigger the Ag NCs that were obtained from the heterodimer NCs. In addition, we demonstrated that all of these NCs were successfully transferred into water by surface modification with biocompatible carboxylic acid groups, which made them meet the basic requirement for biolabeling and biomedical applications.
                                    研究人员成功合成了高质量、单分散和可控尺寸的
Fe3O4、Ag以及双功能     /Ag异质二聚体纳米晶体。在     纳米晶体的合成中,通过使用
十二醇替代
1,2-十六烷二醇,并通过简单调节
配体比例而不是使用籽晶生长法来实现"尺寸控制"。在Ag纳米晶体的合成中,使用有机
银乙酰丙酮(Agacac)作为前驱体,通过调节反应温度可以容易获得可调的粒径。
通过使用不同尺寸的     纳米晶体作为籽晶,成功合成了     部分尺寸为5-16nm、Ag部分尺寸为4-8nm的     /Ag异质二聚体纳米晶体,并保持了超顺磁性。研究发现,附着在     纳米晶体上的Ag尺寸取决于     籽晶的尺寸。紫外-可见吸收光谱和
TEM研究表明,使用的     纳米晶体籽晶越大,从异质二聚体纳米晶体中获得的Ag纳米晶体就越大。
此外,通过表面修饰
生物相容性羧基,所有这些纳米晶体都成功转移到
水相中,这使它们满足了
生物标记和
生物医学应用的基本要求。