Gold nanorod separation and characterization by asymmetric-flow field flow fractionation with UV-Vis detection
Gold nanorod separation and characterization by asymmetric-flow field flow fractionation with UV-Vis detection
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DOI：
10.1007/s00216-012-6547-9
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发表时间：
2013-02-01
影响因子：
4.3
通讯作者：
Hackley, Vincent A.
中科院分区：
文献类型：
--
作者：
Gigault, Julien;Cho, Tae Joon;Hackley, Vincent A.
全面研究了非对称流场流动分馏（A4F）在低展弦比金纳米棒（GNR）分馏和表征中的应用。我们报告了该应用程序的两个新颖方面。第一个解决了A4F分离带正电荷纳米粒子的分析挑战，这是由于带负电荷的天然膜和分析物之间存在相互作用。我们发现流动相组成是控制分馏和减轻膜-分析物相互作用的关键参数。硝酸铵和十六烷基三甲基溴化铵以不同摩尔比的混合物分离gnr，回收率高。第二个方面是在A4F正模洗脱（即布朗模式）中展示gnr的基于形状的分离。我们发现，对于直径相同的纳米粒子，纳米粒子的洗脱是由于宽高比和空间熵的贡献。后一种效果可以用它们在A4F通道内的方向矢量来解释。我们的实验结果证明了Beckett和Giddings描述的非球形分选理论的相关性（Beckett和Giddings， J胶体与界面科学186(1):53-59,1997）。然而，研究表明，该理论在复杂GNR混合物的情况下有其局限性，形状（即纵横比）是控制A4F中GNR洗脱的主要材料参数；GNRs的表观平动扩散系数随长径比增大而增大。最后，本工作中开发的方法的性能是通过从GNR纵横比混合物中分离和表征单个组分来评估的。
The application of asymmetric-flow field flow fractionation (A4F) for low aspect ratio gold nanorod (GNR) fractionation and characterization was comprehensively investigated. We report on two novel aspects of this application. The first addresses the analytical challenge involved in the fractionation of positively charged nanoparticles by A4F, due to the interaction that exists between the negatively charged native membrane and the analyte. We show that the mobile phase composition is a critical parameter for controlling fractionation and mitigating the membrane-analyte interaction. A mixture of ammonium nitrate and cetyl trimethyl ammonium bromide at different molar ratios enables separation of GNRs with high recovery. The second aspect is the demonstration of shape-based separation of GNRs in A4F normal mode elution (i.e., Brownian mode). We show that the elution of GNRs is due both to aspect ratio and a steric-entropic contribution for GNRs with the same diameter. This latter effect can be explained by their orientation vector inside the A4F channel. Our experimental results demonstrate the relevance of the theory described by Beckett and Giddings for non-spherical fractionation (Beckett and Giddings, J Colloid and Interface Sci 186(1):53-59, 1997). However, it is shown that this theory has its limit in the case of complex GNR mixtures, and that shape (i.e., aspect ratio) is the principal material parameter controlling elution of GNRs in A4F; the apparent translational diffusion coefficient of GNRs increases with aspect ratio. Finally, the performance of the methodology developed in this work is evaluated by the fractionation and characterization of individual components from a mixture of GNR aspect ratios.