Ko Sung Hee, Park Pyeong Jun, Han Jongyoon
Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, 20892, USA.
School of Liberal Arts and Sciences, Korea National University of Transportation, Chungju, Chungcheongbuk-do, 27469, Republic of Korea.
Lab Chip. 2023 Oct 10;23(20):4422-4433. doi: 10.1039/d3lc00405h.
Microfabricated slanted nanofilter arrays are a promising technology for integrated biomolecule analysis systems such as online monitoring and point-of-care quality validation, due to their continuous-flow and one-step operation capability. However, an incomplete understanding of the system limits the performance and wider applications of slanted nanofilter arrays. In this paper, we present rigorous theoretical and experimental studies on macromolecule sieving in a slanted nanofilter array. From both stochastic and kinetic models, an explicit theoretical solution describing size-dependent molecule sieving was derived, which was validated using experimental sieving results obtained for various sieving conditions. Our results not only detail the relationship between sieving conditions and sieving efficiency but also demonstrate that sieving is affected by multiple hindrance effects (electrostatic hindrance), not steric hindrance alone. There is an optimal sieving condition for achieving the greatest separation efficiency for DNAs of a certain size range. Small DNA has great size selectivity in small nanofilters and in weak electric fields, whereas large DNA is present in large nanofilters and in strong electric fields. This study provides insights into designing a slanted nanofilter array for particular target applications and understanding the sieving principles in the nanofilter array.
微纳加工的倾斜纳米滤膜阵列是一种很有前景的技术，适用于集成生物分子分析系统，如在线监测和即时护理质量验证，这得益于其连续流动和一步操作的能力。然而，对该系统的不完全理解限制了倾斜纳米滤膜阵列的性能和更广泛的应用。在本文中，我们对倾斜纳米滤膜阵列中的大分子筛分进行了严谨的理论和实验研究。从随机模型和动力学模型中，我们推导出了一个描述尺寸依赖性分子筛分的明确理论解，并使用在各种筛分条件下获得的实验筛分结果对其进行了验证。我们的结果不仅详细阐述了筛分条件与筛分效率之间的关系，还表明筛分受到多种阻碍效应（静电阻碍）的影响，而不仅仅是空间位阻。对于特定尺寸范围的DNA，存在一个实现最大分离效率的最佳筛分条件。小DNA在小型纳米滤膜和弱电场中具有很大的尺寸选择性，而大DNA则存在于大型纳米滤膜和强电场中。这项研究为设计用于特定目标应用的倾斜纳米滤膜阵列以及理解纳米滤膜阵列中的筛分原理提供了见解。
