Creating Sub-50 Nm Nanofluidic Junctions in PDMS Microfluidic Chip via Self-Assembly Process of Colloidal Particles.
Creating Sub-50 Nm Nanofluidic Junctions in PDMS Microfluidic Chip via Self-Assembly Process of Colloidal Particles.
复制标题
DOI：
10.3791/54145
复制
发表时间：
2016-03
期刊：
影响因子：
--
通讯作者：
Xi Wei;Abeer Syed;P. Mao;Jongyoon Han;Yong-Ak Song
中科院分区：
文献类型：
--
作者：
Xi Wei;Abeer Syed;P. Mao;Jongyoon Han;Yong-Ak Song
聚二甲基硅氧烷(PDMS)因其易于成型和粘接以及透明性，是制作微流控器件的主要建筑材料。然而，由于PDMS材料的柔软性，使用PDMS来构建纳米通道是具有挑战性的。在等离子键合过程中，通道容易坍塌。在本文中，我们提出了一种蒸发驱动的二氧化硅胶体纳米颗粒的自组装方法，以在两个微通道之间创建具有小于50 nm孔洞的纳米流体连接。在自组装过程之前，只需改变瓶中组装的微流控装置外部的胶体二氧化硅微珠尺寸和表面官能化，就可以简单地调节纳米流体结的孔径和表面电荷。利用微珠尺寸为300 nm、500 nm和900 nm的纳米粒子自组装，可以制备出孔径分别为~45 nm、~75 nm和~135 nm的多孔膜。在电势作用下，该纳米孔膜作为阳离子选择性膜引发离子浓度极化，在15min内将DNA浓缩1700倍。这种非光刻纳米加工工艺为研究离子和分子在PDMS微流控芯片中的纳米尺度传输过程提供了一个构建可调纳米流控结的新机会。
Polydimethylsiloxane (PDMS) is the prevailing building material to make microfluidic devices due to its ease of molding and bonding as well as its transparency. Due to the softness of the PDMS material, however, it is challenging to use PDMS for building nanochannels. The channels tend to collapse easily during plasma bonding. In this paper, we present an evaporation-driven self-assembly method of silica colloidal nanoparticles to create nanofluidic junctions with sub-50 nm pores between two microchannels. The pore size as well as the surface charge of the nanofluidic junction is tunable simply by changing the colloidal silica bead size and surface functionalization outside of the assembled microfluidic device in a vial before the self-assembly process. Using the self-assembly of nanoparticles with a bead size of 300 nm, 500 nm, and 900 nm, it was possible to fabricate a porous membrane with a pore size of ~45 nm, ~75 nm and ~135 nm, respectively. Under electrical potential, this nanoporous membrane initiated ion concentration polarization (ICP) acting as a cation-selective membrane to concentrate DNA by ~1,700 times within 15 min. This non-lithographic nanofabrication process opens up a new opportunity to build a tunable nanofluidic junction for the study of nanoscale transport processes of ions and molecules inside a PDMS microfluidic chip.