Sheathless Focusing and Separation of Diverse Nanoparticles in Viscoelastic Solutions with Minimized Shear Thinning
Sheathless Focusing and Separation of Diverse Nanoparticles in Viscoelastic Solutions with Minimized Shear Thinning
复制标题
粘弹性溶液中各种纳米粒子的无鞘聚焦和分离，最小化剪切稀化
DOI：
10.1021/acs.analchem.6b04564
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发表时间：
2016-12-20
影响因子：
7.4
通讯作者：
Su, Jiashu
中科院分区：
文献类型：
--
作者：
Liu, Chao;Ding, Baoquan;Su, Jiashu
粘弹性微流控技术成为一种高效、无标记的流体动力学技术，可以浓缩和分离微米级的颗粒，包括血细胞、循环中的肿瘤细胞和细菌。然而，粘弹性微流体对纳米颗粒的操纵仍然是一个主要的挑战，因为作用在较小颗粒上的粘弹力大大降低。与常用的高相对分子质量聚合物溶液不同，这里我们利用低相对分子质量聚氧乙烷(PEO)的水溶液，具有最小的剪切变稀，但有足够的弹性力来高质量地聚焦和分离各种纳米颗粒。在无鞘流的双螺旋微通道中，100 nm聚苯乙烯纳米粒子和2-DNA分子的聚焦效率分别为84%和85%。此外，我们还演示了基于尺寸的两组二元混合物-100/2000 nm PS颗粒和2-DNA分子/血小板的粘弹性分离，均在同一设备中实现了95%的分离效率。我们建议的技术将是一种很有前途的方法，用于浓缩/分离分析化学和纳米技术应用中遇到的纳米颗粒。
Viscoelastic microfluidics becomes an efficient and label free hydrodynamic technology to enrich and separate micrometer-scale particles, including blood cells, circulating tumor cells, and bacteria. However, the manipulation of nanoscale particles by viscoelastic microfluidics remains a major challenge, because the viscoelastic force acting on the smaller particle decreases dramatically. In contrast to the commonly used polymer solutions of high molecular weight, herein we utilize the aqueous solutions of poly(ethylene oxide) (PEO) of low molecular weight with minimized shear thinning but sufficient elastic force for high-quality focusing and separation of various nanoparticles. The focusing efficiencies of 100 nm polystyrene (PS) nanoparticles and 2-DNA molecules are 84% and 85%, respectively, in a double spiral microchannel, without the aid of sheath flows. Furthermore, we demonstrate the size-based viscoelastic separation of two sets of binary mixtures-100/2000 nm PS particles and 2-DNA molecules/blood platelets all achieving separation efficiencies of >95% in the same device. Our proposal technique would be a promising approach for enrichment/separation of the nanoparticles encountered in applications of analytical chemistry and nanotechnology.