Supramolecular DNA Machines and Circuits

杜兰大学的Janarthanan Jayawickramarajah教授得到了化学系大分子、超分子和纳米化学（MSN）项目的支持，设计和研究纳米机器的动力学和可编程特性，这些纳米机器可以将输入信号转换为特定的输出，如运动和形状变化。引入不同的合成主客体成分，最大限度地减少对昂贵的长DNA链的依赖，扩大了纳米机器中可以利用的输入类型，并增加了它们的多功能性。潜在的应用包括开发具有催化和化学传感功能的DNA机器。除了直接影响纳米技术外，该项目还广泛影响多个科学学科，并提供设备开发所需的多功能性，如逻辑门器件、传感/诊断代理和自主系统。在进行这个项目的过程中，学生们接受了跨学科化学研究的教育和训练。此外，通过以化学为基础的服务学习课程，研究与教学和社区服务相结合，该课程涉及杜兰大学本科生在新奥尔良K-12公立学校进行示范。此外，该项目还包括为邻近的泽维尔大学（Xavier University）的少数族裔学生提供暑期本科生研究体验。本项目开发基于葫芦脲7 （CB7）的主客驱动脚位介导链位移（TMSD）作为实现动态超分子DNA机器的指导原则。虽然传统的基于沃森-克里克的TMSD已经成为开发优雅分子设备的基础（比如运载和分类货物的马达，控制蛋白质活动的自主机器人，以及执行计算任务的系统），但这些DNA纳米机器有一个缺点，即它们只利用遗传分子识别，因此系统可以整合（或响应）的输入范围很大程度上限于核酸序列。该项目利用合成的超分子替代物，可以取代（或以互补的方式服务）沃森-克里克碱基配对驱动的TMSD，从而产生对更广泛的刺激有反应的纳米机器，同时也最大限度地减少了所使用的DNA结构域的长度。此外，除了其他突出的超分子化学概念（包括多价和熵驱动的产物形成）外，通过利用基于主-客的TMSD，该项目开发了(a)由客链DNA催化的高阶超分子DNA电路和(b)具有催化放大荧光信号能力的非酶传感器。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Professor Janarthanan Jayawickramarajah of Tulane University is supported by the Macromolecular, Supramolecular, and Nanochemistry (MSN) Program of the Division of Chemistry to design and study the dynamics and programmable nature of nanomachines that can transduce input signals into specific outputs, such as motion and shape change. The introduction of different synthetic host-guest components, minimizes the dependence on costly long DNA chains, expands the types of inputs that can be utilized within the nanomachines and increases their versatility. Potential applications include the development of DNA machinery that have catalytic and chemical sensing functions. In addition to directly impacting nanotechnology, the project broadly impacts multiple scientific disciplines and provides the versatility needed for device development, such as logic gate devices, sensing/diagnostic agents, and autonomous systems. During the course of conducting this project, students are educated and trained in inter-disciplinary chemical research. Furthermore, research is integrated with teaching and community service via a chemistry-based service-learning course that involves Tulane undergraduate students conducting demonstrations at New Orleans K-12 public schools. In addition, the project includes a summer undergraduate research experience for diverse groups of students from mostly underrepresented minorities at neighboring Xavier University.This project develops cucurbituril 7 (CB7) based host-guest driven toehold mediated strand displacement (TMSD) as a guiding principle to achieve dynamic supramolecular DNA machines. While conventional Watson-Crick based TMSD has been foundational in the development of elegant molecular devices (such as motors to carry and sort cargo, autonomous robots that control protein activity, and systems that conduct computing tasks), these DNA nanomachines have the drawback that they only harness genetic molecular recognition and thus the scope of inputs that the systems can incorporate (or respond to) is largely limited to nucleic acid sequences. This project utilizes synthetic supramolecular surrogates that can replace (or serve in a complementary fashion to) Watson-Crick base-pairing driven TMSD and thus generates nanomachines that are responsive to a broader variety of stimuli whilst also minimizing the length of the DNA domains that are used. Furthermore, by harnessing host-guest based TMSD, in addition to other salient supramolecular chemistry concepts (including multivalency and entropy-driven product formation), the project develops (a) higher-order supramolecular DNA circuits that are catalyzed by guest-linked DNA and (b) non-enzyme based sensors with the capacity for catalytically amplified fluorescence signaling.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.