Free Energy Landscaping for Single-Molecule Biophysics

非技术性：布朗大学材料研究部生物材料项目的这一奖项由生物基础设施部（BIO）生物研究项目的仪器开发共同资助。该奖项将研究“芯片实验室”技术，通过使生物医学测试更小，更便宜，更快来改善医疗保健。最终的极限将是对单个分子的测试。该项目旨在通过开发控制单个DNA分子的形状和运动的强大方法，在这个方向上迈出重要一步。有了这个奖项，技术将被开发，需要纳米流体设备“通道的尺寸只有几十到几百纳米宽”，因为他们可以利用物理概念，只适用于该规模。例如，一个内部具有纳米级地形特征的流体装置，如纳米沟槽，利用DNA分子的熵来引导其运动，甚至将其扭曲成预定的形状。熵是聚合物可以采用的大量微观不同形状的度量。利用纳米流体的场效应（晶体管就是基于这种场效应），也可以静电操纵DNA分子。在这个项目中的实验将推进我们对纳米流体和聚合物物理的基本理解。该项目还将对单个DNA分子进行控制，以获得单个分子的重叠限制性图谱，这可以增加补充下一代基因组测序数据的远程序列信息的通量。这个跨学科的项目将为研究生和本科生在高科技经济的快速增长领域的职业生涯做好准备。此外，收集到的单个DNA分子被一个接一个地控制的视频将用于布朗大学的教室和附近的公立小学。技术支持：该奖项旨在开发控制纳米流体装置内单个DNA分子的构型和运输的新方法。所提出的方法依赖于影响自由能景观的nanobolined的。本研究人员将研究如何嵌入在纳米缝内的一系列沟槽通过减少浅区域中的配置数量来控制聚合物的配置熵。研究人员还将探索设备的带电内表面如何通过库仑力影响受限分子的焓，库仑力可以使用电极进行局部调整。这些新的控制模式应该能够对单个DNA分子和新的生物分析应用进行基础研究。随机共振和噪声辅助运输的DNA将研究在一个合成的，颠簸的自由能景观。类似的装置将用于通过在分子被捕获并在长纳米沟中拉伸时对该分子顺序地进行多次限制性酶切来创建相同DNA分子的重叠限制性图谱。该项目将推动“芯片实验室”的应用，为研究生和本科生提供极好的培训机会，并将支持对当地公立学校的推广活动。

Non-technical: This award by the Biomaterials program in the Division of Materials Research to Brown University is cofunded by the Instrument Development for Biological Research program in the Division of Biological Infrastructure (BIO). This award will study "Lab-on-a-chip" technology in improving healthcare by making biomedical tests smaller, cheaper, and faster. The ultimate limit would be tests on single molecules. This project aims to take an important step in that direction by developing powerful ways of controlling the shape and the motion of single DNA molecules. With this award, techniques will be developed that require nanofluidic device "channels with dimensions only tens to hundreds of nanometers across" because they can exploit physical concepts that only apply at that scale. For instance, a fluidic device with nanoscale topographic features inside it, like nanotrenches, harnesses the entropy of a DNA molecule to guide its motion or even contort it into predetermined shapes. Entropy is a measure of the multitude of microscopically different shapes a polymer can adopt. It is also possible to manipulate a DNA molecule electrostatically, using a nanofluidic version of the field effect upon which transistors are based. The experiments in this project will advance our fundamental understanding of nanofluidics and polymer physics. This project will also apply control over single DNA molecules to obtain overlapping restriction maps of a single molecule, which can increase the throughput of long-range sequence information that complements next-generation genomic sequencing data. This interdisciplinary project will prepare graduate and undergraduate students for careers in a rapidly growing area of the high-technology economy. Furthermore, the videos collected of single DNA molecules being controlled one by one will be used in the classroom at Brown University and in the nearby public elementary schools. Technical: This award is to develop new methods in controlling the configurations and the transport of single DNA molecules inside nanofluidic devices. The proposed methods rely on influencing the free energy landscape for a nanoconfined polyelectrolyte. This researcher will investigate how a series of trenches embedded within a nanoslit governs the configurational entropy of a polymer through the reduction of the number of configurations available in shallow regions as compared with deeper regions. The investigator will also explore how the charged inner surfaces of a device influence the enthalpy of a confined molecule through Coulomb forces, which can be locally tuned using electrodes. These new modalities of control should enable fundamental studies on single DNA molecules and new bio-analytical applications. Stochastic resonance and noise-assisted transport of DNA will be studied in a synthetic, bumpy free energy landscape. A similar device will be used to create overlapping restriction maps of the same DNA molecule by performing multiple restriction digests, sequentially, on the molecule as it is trapped and stretched in a long nanotrench. This project will advance "lab-on-a-chip" applications, provide excellent training opportunities for graduate and undergraduate students, and will support outreach activities to local public schools.