Innes Laura M, Chen Chin-Hsuan, Schiel Matthew, Pevarnik Matthew, Haurais Florian, Toimil-Molares Maria Eugenia, Vlassiouk Ivan, Theogarajan Luke, Siwy Zuzanna S
Department of Physics and Astronomy, University of California , Irvine, California 92697, United States.
Anal Chem. 2014 Oct 21;86(20):10445-53. doi: 10.1021/ac502997h. Epub 2014 Oct 6.
Pores with undulating opening diameters have emerged as an analytical tool enhancing the speed of resistive-pulse experiments, with a potential to simultaneously characterize size and mechanical properties of translocating objects. In this work, we present a detailed study of the characteristics of resistive-pulses of charged and uncharged polymer particles in pores with different aspect ratios and pore topography. Although no external pressure difference was applied, our experiments and modeling indicated the existence of local pressure drops, which modified axial and radial velocities of the solution. As a consequence of the complex velocity profiles, pores with undulating pore diameter and low-aspect ratio exhibited large dispersion of the translocation times. Distribution of the pulse amplitude, which is a measure of the object size, was not significantly affected by the pore topography. The importance of tuning pore geometry for the application in resistive-sensing and multipronged characterization of physical properties of translocating objects is discussed.
孔径呈波浪状变化的孔已成为一种分析工具，可提高电阻脉冲实验的速度，并有可能同时表征易位物体的尺寸和机械性能。在这项工作中，我们详细研究了不同纵横比和孔形貌的孔中带电和不带电聚合物颗粒的电阻脉冲特性。尽管未施加外部压差，但我们的实验和建模表明存在局部压降，这改变了溶液的轴向和径向速度。由于复杂的速度分布，孔径呈波浪状且纵横比低的孔表现出较大的易位时间分散性。作为物体尺寸度量的脉冲幅度分布，并未受到孔形貌的显著影响。本文还讨论了调整孔几何形状对于电阻传感应用以及对易位物体物理性质进行多方面表征的重要性。
