Vectorially-Coupled Reaction Networks in Low-Dimensional Nanofluidic Structures

反应是化学的中心事件，控制它们的行为和它们发生的位置是化学测量和制造新化学品的核心。理想情况下，科学家希望设计反应，使它们快速发生，有效利用所有化学参与者，使用廉价的化学品和环境友好的条件，并生产容易分离的化学产品。在自然界中，例如在生物细胞中，这些严格的目标是通过空间组织的反应网络来实现的。Paul Bohn博士在圣母大学的研究小组通过设计和开发反应网络来模仿自然，这些反应网络的行为由电刺激控制，其位置由反应容器的大小定义。在电子转移反应的工作中，他们仔细地从纳米尺寸的材料中构建专门设计的结构，其性质和位置导致在特定位置发生特定的，明确的和高效的反应。此外，对位置特定的反应和附近液体的移动的电控制允许化学产物从一个反应位置穿梭到下游的另一个反应位置，在下游，它们被用作另一个限定的反应过程的化学起始材料。所有的反应都是使用酶加速的，酶是自然界的化学反应催化剂。 Bohn团队正在研究如何应用电压来控制催化剂的活性。研究工作与新的教育和培训计划相结合，这些计划跨越了圣母大学的学科界限，并将多所大学的联合收割机人才结合起来。在此过程中，这些活动涉及具体的NSF目标，包括发展多样化的，具有全球竞争力的科学-技术-工程-数学劳动力;增加学术界和工业界之间的伙伴关系;该项目的主要目标是由化学测量和成像计划以及分子分离，电化学系统和过程系统的部分共同资助，NSF的反应工程和分子热力学计划是开发空间组织的氧化还原反应网络，这些反应可以通过电信号控制，以管理运输，指示反应性和分离产物。总体目标是通过开发控制反应物分子和颗粒的传递到反应位点以及控制反应性，在零维和一维电化学纳米结构。 该团队还结合这些纳米结构来开发对级联反应的全三维控制，以产生矢量控制反应网络（VCRN）。第一个目标是开发高精度的纳米级架构，以支持VCRN的同时控制传输和反应，使用金属-绝缘体多层堆叠为基础的纳米孔和分层组织的组件。第二个目的是探索电化学势可用于控制与电极之一结合的酶的活性的方法。使用辣根过氧化物酶，HRP，作为模型氧化还原酶，使用荧光氧化还原反应，将非荧光反应物转化为荧光产物内的电化学零模式波导的荧光灵敏度环境中的电极结合的酶的固有反应性。这些能力正在结合起来，并使用一组严格的单酶动力学实验，其中的HRP之间移动的可用位置和测试的内在反应性时，耦合到一个电化学电位控制信号进行测试。这项工作的最终目标是利用单一反应事件的控制来创建VCRN的制备规模能力。为了测试这种能力，双酶电化学调节反应系统以空间协调的方式耦合到各个反应，并用于将反应产物递送到下游收集点。该项目的影响超出了化学分析的主要学科，特别是在级联反应的一般领域-化学合成中使用的强大结构，例如，该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响进行评估，被认为值得支持审查标准。

Reactions are the central events of chemistry and controlling their behavior and the locations where they occur is at the heart of chemical measurements and making new chemicals. Ideally, scientists want to design reactions so they occur rapidly, make efficient use of all the chemical participants, employ inexpensive chemicals and environmentally friendly conditions, and produce easily-isolated chemical products. In nature, such as in biological cells, these stringent objectives are achieved by spatially-organized reaction networks. Dr. Paul Bohn's research team at the University of Notre Dame mimics nature by designing and developing networks of reactions whose behavior is controlled by electrical stimulus and whose location is defined by the size of the reaction vessel. In their work with electron-transfer reactions, they carefully build specially-designed structures from nanometer-sized materials, whose nature and placement leads to particular, well-defined, and highly efficient reactions occurring in specific locations. Furthermore, electrical control of the location-specific reactions and movement of nearby liquid allows for shuttling of chemical products from one reaction site to another one downstream, where they are used as the chemical starting materials for another defined reaction process. All the reactions are sped up using enzymes, nature's chemical reaction catalysts. The Bohn team is developing an understanding of how electrical voltages can be applied to control the activity of catalysts. The research efforts are integrated with new education and training programs that cut across disciplinary lines within the University of Notre Dame and combine talents from multiple universities. In the process, these activities address specific NSF goals including development of a diverse, globally competitive science-technology-engineering-mathematics workforce; increased partnerships between academia and industry; and improved economic competitiveness.The principal goal of this project supported by the Chemical Measurement and Imaging Program and partial co-funding from the Molecular Separations, Electrochemical Systems, and Process Systems, Reaction Engineering and Molecular Thermodynamics Programs at NSF is to develop networks of spatially-organized redox reactions which can be controlled by electrical signals to manage transport, dictate reactivity, and isolate products. The overall goal is addressed by developing control over delivery of reactant molecules and particles to a reactive site as well as control over reactivity, within zero- and one-dimensional electrochemical nanostructures. The team also combines these nanostructures to develop full three-dimensional control over cascade reactions to produce vectorially-controlled reaction networks (VCRNs). The first objective is the development of high-precision nanoscale architectures to support VCRNs by simultaneous control over transport and reactivity using both metal-insulator multilayer stack-based nanopores and hierarchically-organized assemblies. The second objective explores ways in which electrochemical potential can be used to control activity of enzymes bound to one of the electrodes. Using horseradish peroxidase, HRP, as a model oxidoreductase enzyme, the intrinsic reactivity of the electrode-bound enzyme is followed using a fluorogenic redox reaction that converts a non-fluorescent reactant into fluorescent product within the ultrahigh sensitivity environment of an electrochemical zero-mode waveguide. These capabilities are being combined and tested using a set of stringent single enzyme kinetics experiments, in which the HRP is moved among the available locations and tested for intrinsic reactivity when coupled to an electrochemical potential control signal. The ultimate goal of this work is to leverage control of single reaction events to create a preparative scale capability for VCRNs. To test this capability, two-enzyme electrochemically-modulated reaction systems are being coupled to individual reactions in a spatially coordinated manner and used to deliver the reaction products to a downstream collection point. This project has impact outside the principal discipline of chemical analysis, especially in the general area of cascade reactions - powerful constructs in chemical synthesis that are used, for example, in enzymatic biofuel cells to capture the full electrochemical reducing power of fuel sources.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.