Single Molecule Electrophoresis using Nanochannel Columns Fabricated in Thermoplastics

有了这个奖项，化学系的化学测量和成像计划以及国际科学与工程办公室的全球风险投资基金正在支持Steven A.查佩尔山的北卡罗来纳州大学的Soper博士，致力于对塑料柱在纳米级分离（如电泳）中的应用提出新的见解。活动包括：了解使用压印在塑料中生产纳米柱的技术（与生产DVD光盘的技术相同），修改塑料的表面特性，最后使用具有纳米尺寸的塑料柱进行具有独特操作特性的分离。更广泛的影响部分地通过纳米级电泳在一些引人注目的领域中的应用效用来证明，例如DNA或RNA测序，其可以提供关于由环境影响诱导的DNA/RNA分子的序列内容的变化的信息，识别生物病原体，和/或寻找菌株特异性细菌或病毒感染。该项目小组由北卡罗来纳州大学（美国）和韩国蔚山国家科学技术研究所（UNIST）的研究人员组成，他们建立了富有成效的研究合作。参加该项目的10名研究生将在UNIST工作12个月，利用UNIST的研究基础设施和专业知识，体验真正的全球研究环境，实现该合作项目的具体目标。该项目采用多学科方法，包括转录组学，RNA/DNA测序，以及检测DNA中的表观遗传序列变异，以开发使用纳米柱的单分子电泳领域。所采用的柱是不寻常的，因为它们包含宽度和深度为纳米尺寸（200 nm）但长度为50 µm的纳米通道。 这些是用纳米压印光刻法在热塑性塑料中制造的。小分子和生物聚合物的电泳研究通过监测运输的适当准备的目标;目标标记有荧光标记，以便运输动力学可以使用粒子跟踪和荧光显微镜监测纵向运动或超分辨率荧光成像确定横向电迁移。一个主机的表面改性调用的纳米通道，以了解表面电荷密度和这些修改的均匀性对单分子的运输动力学的影响。虽然这些修饰策略已在微通道中得到证实，但它们尚未在纳米通道中得到证实。这两种分子类型的运输都是使用新格式的“超分辨率”显微镜进行的，其目的是实现前所未有的灵敏度以及空间和时间分辨率。 该技术也可能有助于阐明电动运输性质的情况下，柱尺寸是类似的德拜长度。

With this award, the Chemical Measurement and Imaging Program of the Division of Chemistry as well as by the Global Ventures Fund of the Office of International Science and Engineering is supporting Professor Steven A. Soper of the University of North Carolina, Chapel Hill to develop new insights into the use of plastic-based columns for nanoscale separations, such as electrophoresis. Activities include: understanding techniques to produce nano-columns in plastics using imprinting (the same technique used to produce DVD disks), modifying the surface properties of plastics and finally, using plastic columns with nanometer dimensions to undertake separations with unique operating characteristics. The broader impacts are demonstrated in part through the application utility of nanoscale electrophoresis in a number of compelling areas such as DNA or RNA sequencing, which can provide information on variations in the sequence content of a DNA/RNA molecule induced by environmental effects, identifying biopathogens, and/or looking for strain-specific bacterial or viral infections. The project team is comprised of researchers at the University of North Carolina (USA) and at Ulsan National Institute of Science and Technology (UNIST) in South Korea, who have established a productive research collaboration. UNC graduate students participating in this project will spend 12 months at UNIST to work on specific aims of this collaborative project, taking advantage of the research infrastructure and expertise at UNIST and experiencing a truly global research environment.This project takes a multi-disciplinary approach that includes transcriptomics, RNA/DNA sequencing, and detection of epigenetic sequence variations in DNA to develop the area of single-molecule electrophoresis using nanometer columns. The columns that are employed are unusual in that they contain nanochannels with nano-dimensions (200 nm) in width and depth, but lengths of 50 µm. These are fabricated in thermoplastics using nanoimprint lithography. The electrophoresis of both small molecules and biopolymers are investigated by monitoring the transport of the appropriately prepared targets; the targets are labeled with fluorogenic tags so that the transport dynamics can be monitored using particle tracking and fluorescence microscopy for longitudinal motions or super-resolution fluorescence imaging for determining transverse electromigration. A host of surface modifications are invoked on the nanochannels to understand the effects of surface charge density and the homogeneity of these modifications on the transport dynamics of single molecules. While these modification strategies have been demonstrated in microchannels, they are yet unproven in nanochannels. The transport of both molecule types are undertaken using new formats of 'super-resolution' microscopy that aims to achieve unprecedented sensitivity, and spatial and time resolution. The technique may also help to elucidate electrokinetic transport properties in the case where column dimensions are similar to the Debye length.