Actively Controlled Transport with Molecular Assemblies

圣母大学的Paul W. Bohn教授得到化学学部化学测量和成像项目的支持，开发多功能纳米级流体装置。该项目研究如何构建设备，使单个结构可以同时切换流体流动，感知特定分子的存在，并随后对这些分子进行处理-可能是修复环境污染物或破坏体内循环的有害生物分子。施加在设备不同区域的电位使小体积的流体通过特定通道移动，以进行传感和处理。这些项目试图将这种电激活的流体流动与电化学反应和敏感的化学传感方法结合起来——基于电化学反应后分子的发光或金属与周围流体的高频激发的相互作用。进行电化学反应的一个关键挑战是它们必须发生在远离地电位的地方，而这种反应通常在地电位处进行。因此，该项目旨在开发在任意大电压下进行电化学转换的新方法。第二个挑战是，由于结构非常小，在任何给定时间只有极少数分子可能发生反应。因此，该项目寻求开发新的高灵敏度方法来跟踪电子转移反应，这种方法适用于超小样品，甚至是单分子。这个项目对社会的广泛影响体现在三个方面。首先，科学工作解决了微型分析装置中流体流动的控制和操纵，这是国际科学界越来越感兴趣的问题。第二，科学工作通过让代表人数不足的群体和妇女参与各种学生的参与，有助于科学人力资源开发。第三个领域是通过与英国剑桥大学世界领先的生物电化学实验室之一的学生交换，帮助学生了解科学的国际层面。

Professor Paul W. Bohn of the University of Notre Dame is supported by the Chemical Measurement and Imaging Program in the Division of Chemistry to develop multifunctional nanoscale fluidic devices. The project investigates how devices can be constructed so that a single structure can simultaneously switch fluid flow, sense the presence of specific molecules and subsequently subject these molecules to treatment - perhaps remediation of an environmental pollutant or destruction of a harmful biomolecule circulating in the body. Electrical potentials applied to different regions of the device cause small volumes of fluid to move through specific channels for sensing and treatment. The projects seek to combine this electrically-activated fluid flow with electrochemical reactions and with sensitive methods of chemical sensing - based either on the luminescence of the molecules after electrochemical reaction or the interaction of high frequency excitations in metals with the surrounding fluid. One critical challenge in carrying out the electrochemical reactions is that they must occur far from ground potential, where such reactions routinely are carried out. Thus, the project aims to develop new ways to perform electrochemical transformations at arbitrarily large voltages. The second challenge is that because the structures are so small, only a tiny number of molecules may react at any given time. Thus, the project seeks to develop new highly sensitive methods of following electron transfer reactions that are applicable to ultrasmall samples, even to single molecules.The broader impact of this program on society is felt in three ways. First, the scientific work addresses the control and manipulation of fluid flow in miniature analytical devices, a problem of growing interest to the international scientific community. Second, the scientific work contributes to scientific human resource development through the involvement of a diverse range of students with participation from under-represented groups and women. The third area lies in helping students learn about the international dimension of science through a student exchange with one of the world's leading bioelectrochemistry laboratories at Cambridge University, Cambridge, UK.