RUI: Characterizing the birth of a nanoparticle: toward molecular control over nanoparticle synthesis

RUI：表征纳米粒子的诞生：对纳米粒子合成的分子控制

• 批准号: 1764441
• 负责人: Krista Vikse
• 金额: $ 24.48万
• 依托单位: San Francisco State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2019-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1764441&HistoricalAwards=false
• 关键词: RUI; Characterizing; birth; nanoparticle; toward

Scientists are striving to gain precise control over the creation of nanoparticles and nanomaterials. If this goal is achieved, society will gain access to customizable nanomaterials that can be made-to-order for applications including targeted drug delivery, diagnostic imaging and chemical separations. However, while scientists understand how nanoparticles grow in size, it is still not clear how nanoparticles are born. Without understanding this very first step of nanoparticle formation, scientists cannot rationally design protocols that will deliver custom nanomaterials. In this project, Professor Krista Vikse of San Francisco State University conducts experiments to uncover the exact details of how the seed of a nanoparticle forms. At the same time, Professor Vikse is developing enhanced educational infrastructure for undergraduate students who are working in an active chemical research laboratory for the first time. Scannable Quick Response (QR) codes are being incorporated into the physical research space. Using their cell phones, student can scan these codes to link to relevant virtual training materials on-demand. In this way, Dr. Vikse is aiming to make STEM research more accessible and less intimidating for all students, with a particular focus on groups of students who are underrepresented in the field of chemistry.With funding from the Macromolecular, Supramolecular and Nanochemistry Program of the NSF Chemistry Division, Professor Krista Vikse of San Francisco State University is elucidating the atomically precise mechanism for the early reduction and nucleation events in gold citrate nanoparticle formation. The focus is on the first stage of formation as the clusters grow from 2 - 10 metal atoms. To this end, nanoparticle synthesis reaction mixtures are monitored in operando using pressurized sample infusion mass spectrometry (PSI-MS). Kinetic data are collected for all reactive species. Key intermediates are intercepted within the mass spectrometer and gas-phase ion-molecule reactions are conducted to probe the structure and inherent reactivity of each intermediate. Finally, Density Functional Theory (DFT) calculations elucidate detailed structure-activity relationships based on the experimentally collected gas-phase data. A complete molecular understanding of the formation of gold nanoparticles facilitates the rational design of metallic nanoparticle cores and also informs the field of metal cluster catalyzed reactions. As an integral part of this project, Dr. Vikse and her students develop and test educational infrastructure for undergraduate students who are working in an active research laboratory for the first time. Scannable Quick Response (QR) codes are placed in key locations around the laboratory giving students direct, on-demand access to virtual instructional materials using their cell phones. This allows for increased accessibility to standardized training and timely reminders of best practices in the laboratory. The goal is to improve student confidence in a STEM laboratory setting and ultimately attract students to the STEM profession.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.

科学家们正在努力获得对纳米粒子和纳米材料产生的精确控制。如果这一目标得以实现，社会将获得可定制的纳米材料，这些纳米材料可以用于包括靶向药物输送、诊断成像和化学分离在内的应用。然而，虽然科学家们了解纳米粒子是如何在尺寸上增长的，但他们仍然不清楚纳米粒子是如何诞生的。如果不了解纳米粒子形成的第一步，科学家就无法合理地设计出定制纳米材料的方案。在这个项目中，旧金山州立大学的克里斯塔·维克斯教授通过实验揭示了纳米粒子种子形成的确切细节。与此同时，Vikse教授正在为首次在活跃的化学研究实验室工作的本科生开发增强的教育基础设施。可扫描的快速响应（QR）码正被纳入物理研究空间。学生可以用手机扫描这些代码，按需链接到相关的虚拟培训材料。通过这种方式，Vikse博士的目标是让STEM研究对所有学生来说更容易获得，更不令人生畏，特别关注那些在化学领域代表性不足的学生群体。在美国国家科学基金会化学部大分子、超分子和纳米化学项目的资助下，旧金山州立大学的Krista Vikse教授正在阐明柠檬酸金纳米颗粒形成过程中早期还原和成核事件的原子精确机制。重点是在2 - 10个金属原子形成团簇的第一阶段。为此，使用加压样品输注质谱（PSI-MS）在operando中监测纳米颗粒合成反应混合物。收集了所有反应物质的动力学数据。在质谱仪内截取关键中间体，并进行气相离子分子反应，以探测每种中间体的结构和固有反应性。最后，密度泛函理论（DFT）计算阐明了基于实验收集的气相数据的详细构效关系。对金纳米颗粒形成的完整的分子理解有助于金属纳米颗粒芯的合理设计，也为金属团簇催化反应领域提供了信息。作为该项目的一个组成部分，Vikse博士和她的学生为第一次在活跃的研究实验室工作的本科生开发和测试教育基础设施。可扫描的快速响应（QR）码放置在实验室周围的关键位置，让学生使用手机直接按需访问虚拟教学材料。这样可以增加标准化培训的可及性，并及时提醒实验室的最佳实践。目标是提高学生对STEM实验室环境的信心，并最终吸引学生从事STEM职业。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。