Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, USA.
ACS Nano. 2012 Jun 26;6(6):5596-604. doi: 10.1021/nn301536n. Epub 2012 May 29.
We demonstrate the synthesis of water-soluble allylamine-terminated Fe-doped Si (Si(xFe)) nanoparticles as bimodal agents for optical and magnetic imaging. The preparation involves the synthesis of a single-source iron-containing precursor, Na(4)Si(4) with x% Fe (x = 1, 5, 10), and its subsequent reaction with NH(4)Br to produce hydrogen-terminated Si(xFe) nanoparticles. The hydrogen-capped nanoparticles are further terminated with allylamine via thermal hydrosilylation. Transmission electron microscopy indicates that the average particle diameter is ∼3.0 ± 1.0 nm. The Si(5Fe) nanoparticles show strong photoluminescence quantum yield in water (∼10%) with significant T(2) contrast (r(2)/r(1) value of 4.31). Electron paramagnetic resonance and Mössbauer spectroscopies indicate that iron in the nanoparticles is in the +3 oxidation state. Analysis of cytotoxicity using the resazurin assay on HepG2 liver cells indicates that the particles have minimal toxicity.
我们展示了水溶性烯丙胺封端的 Fe 掺杂 Si（Si(xFe)）纳米粒子的合成，该纳米粒子可用作光学和磁共振双模态成像造影剂。该制备方法涉及到一种单源含铁前体 Na(4)Si(4)与 x% Fe（x = 1、5、10）的合成，以及其与 NH(4)Br 的后续反应，以产生氢封端的 Si(xFe)纳米粒子。氢封端的纳米粒子进一步通过热硅氢化反应用烯丙胺封端。透射电子显微镜表明，平均粒径约为 3.0 ± 1.0nm。Si(5Fe)纳米粒子在水中具有很强的光致发光量子产率（约 10%），并具有显著的 T(2)对比（r(2)/r(1) 值为 4.31）。电子顺磁共振和穆斯堡尔谱表明，纳米粒子中的铁处于+3 氧化态。利用 HepG2 肝癌细胞的 Resazurin 测定法分析细胞毒性表明，这些粒子的毒性很小。
