Collaborative Research: Understanding the Design Principles of Modular Nanopores for Highly Efficient Chemical Sensing

本项目由化学学部化学测量与成像项目资助。堪萨斯州立大学的Takashi Ito教授、印第安纳大学布卢明顿分校的Amar Flood教授和Yi Yi博士试图设计圆柱形纳米级孔（直径10-40纳米，长度30-100纳米；一英寸有2540万纳米），用于有效的化学分离和检测。以氯离子为模型目标。这项工作研究了氯是如何通过纳米孔的几何形状和物理环境进行化学识别的。假设通过调节纳米孔内的环境和电荷可以提高化学识别的选择性、特异性和强度。控制纳米孔物理内部的化学识别可以是一个通用的基本原则，用于设计各种物种的高效分离，包括那些对环境感兴趣的，如肥料中的化学物质。改善阴离子传感的直接社会影响是水净化和分析的改善。用于体内测量的微型阴离子传感器也在研究中。这些研究成果与教育活动相结合，通过开发一个新的动手聚合物实验课程，包括聚合物合成和表征。系统研究了基于聚合物的圆柱形纳米孔（孔径10-40 nm，孔长30-100 nm），以评估纳米孔物理环境对化学识别和氧化还原相关电荷传输的影响。以表面炔基修饰的纳米孔被各种叠氮化物标记的阴离子受体和氧化还原基团共价修饰。对纳米孔设计原理的基本理解为合理制备单片纳米孔膜和薄膜提供了一种有效的化学分离和检测方法。研究了具有可控孔取向和孔尺寸的炔修饰纳米孔支架的制备和表征。接下来是了解纳米孔的物理环境对阴离子识别和电荷传输的影响。第三个研究领域是氧化还原控制阴离子传感。利用光谱和电化学技术对模块化纳米孔的阴离子识别和电化学性能进行了评估。研究人员在这个跨学科项目中具有互补的专业知识：纳米结构薄膜的电化学和光谱学（Ito），阴离子受体“点击”反应的设计、合成和表征（Flood），以及嵌段共聚物合成（Yi）。本课题的研究结果为设计更好的无机离子化学传感介质提供了基础知识，这在水质控制和生物科学中具有重要意义。

This project is funded by the Chemical Measurement and Imaging Program of the Chemistry Division. Professor Takashi Ito of Kansas State University, and Professor Amar Flood, and Dr. Yi Yi, both from Indiana University - Bloomington seek to design cylindrical nanoscale pores (pores 10-40 nanometers in diameter and 30-100 nanometers in length; there are 25,400,000 nanometers in one inch) for efficient chemical separations and detection. Chloride ion is used as the model target. This work examines how chloride can be chemically recognized by the nanopore geometry and physical environment. It is hypothesized that selectivity, specificity, and strength of chemical recognition can be enhanced by adjusting the environment and charge inside the nanopores. The control of the nanopore physical interior for chemical recognition can be a versatile, basic principle for designing highly efficient separations for various species, including those of environmental interest such as chemicals in fertilizers. A direct societal impact of improved anion sensing is improvement in water purification and analysis. Microscale anion sensors for measurements within the body are also being pursued. These research achievements are integrated with educational activities by developing a new hands-on polymer lab course that includes both polymer synthesis and characterization. Systematic investigations explore polymer-based cylindrical nanopores (10-40 nm in pore diameter; 30-100 nm in pore length) to assess the effects of nanopore physical environment on chemical recognition and redox-involved charge transport. Nanopores decorated with surface alkyne groups are covalently modified with various azide-tagged anion receptors and redox moieties. The fundamental understanding of the nanopore design principles present an approach to rationally fabricate monolithic nanoporous membranes and films for efficient chemical separations and detection. The research focuses on the fabrication and characterization of alkyne-decorated nanoporous scaffolds with controlled pore orientation and dimensions. This is followed by understanding of the effects of nanopore's physical environment on anion recognition and charge transport. The third area of research is the redox-controlled anion sensing. The anion recognition and electrochemical properties of modular nanopores are assessed using spectroscopic and electrochemical techniques. The investigators have complementary expertise for this interdisciplinary project: electrochemistry and spectroscopy on nanostructured films (Ito), design, synthesis and characterization of anion receptors with "click" reactions (Flood), and block copolymer synthesis (Yi). Results obtained in this project provide fundamental knowledge required to design better chemical sensing media of inorganic ions which are of special importance in water quality control and biosciences.