CAS: Elucidating How Nanocrystal Structure Controls Electron Flow in Nanocrystal-Enzyme Complexes

CAS：阐明纳米晶体结构如何控制纳米晶体-酶复合物中的电子流

• 批准号: 2204639
• 负责人: Gordana Dukovic
• 金额: $ 49.97万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2204639&HistoricalAwards=false
• 关键词: CAS; Elucidating; How; Nanocrystal; Structure

With support from the Macromolecular, Supramolecular, and Nanochemistry (MSN) program in the Division of Chemistry, Professor Gordana Dukovic of University of Colorado Boulder is combining synthesis, advanced laser techniques, and high-resolution microscopy to follow the flow of electrons in nanocrystal-enzyme complexes capable of light-driven hydrogen production. To make hydrogen, the nanocrystal is first excited by light, increasing the energy of its electrons. These excited electrons must then hop from the nanocrystal to the enzyme, and then make their way to the enzyme's reaction center by hopping from one site to another, like crossing a stream by jumping from stone to stone. Each of these electron hops is important for hydrogen production, but they are difficult to observe and control. Professor Dukovic and her students will measure the times of the critical electron hopping events, and how they depend on nanocrystal structure, surface properties, and binding to the enzyme. Their discoveries could lead to new ways to use sunlight to make chemicals, including solar fuels. Additionally, the project is helping to foster the Nation's science, technology, engineering, and mathematics (STEM) workforce by supporting career development of junior faculty and scientists, as well as the undergraduate education of students from a variety of backgrounds. This project will elucidate the electron pathways involved in photochemical H2 generation that occurs when photoexcited semiconductor nanocrystals transfer electrons to the adsorbed enzyme hydrogenase, which catalyzes proton reduction to H2. The project will examine how properties of nanocrystalline quantum dots (QDs) such as composition, diameter, and surface chemistry impact the QD binding with the enzyme, the transfer of photoexcited electrons, and other critical processes for H2 production, such as hole scavenging and back-electron transfer from the enzyme. The outcome of the project will be an improved understanding of how nanocrystals drive enzyme catalysis. This, in turn, will lead to design principles for how to use the immense tunability of nanocrystal structure and properties to adapt them to drive complex, multi-step light-driven chemistry.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.

在化学系大分子、超分子和纳米化学(MSN)计划的支持下，科罗拉多大学博尔德大学的Gordana Dukovic教授正在结合合成、先进的激光技术和高分辨率显微镜来跟踪能够光驱动制氢的纳米晶体-酶复合体中的电子流动。为了制造氢气，纳米晶体首先被光激发，增加其电子的能量。然后，这些被激发的电子必须从纳米晶体跳到酶上，然后通过从一个位置跳到另一个位置来到达酶的反应中心，就像通过从一个石头跳到另一个石头来跨越一条小河一样。这些电子跃迁中的每一个对氢气的产生都很重要，但它们很难观察和控制。杜科维奇教授和她的学生将测量关键电子跳跃事件的时间，以及它们如何依赖于纳米晶体结构、表面属性和与酶的结合。他们的发现可能会带来利用阳光制造包括太阳能燃料在内的化学品的新方法。此外，该项目通过支持初级教师和科学家的职业发展以及对不同背景的学生的本科教育，帮助培养国家的科学、技术、工程和数学(STEM)劳动力。本项目将阐明当光激发半导体纳米晶体将电子转移到吸附的酶氢酶时，光化学生成H2所涉及的电子路径，该酶催化质子还原为H2。该项目将研究纳米晶体量子点(QD)的组成、直径和表面化学等性质如何影响QD与酶的结合、光激发电子的转移以及其他产生氢气的关键过程，如清除空穴和酶的背电子转移。该项目的成果将是对纳米晶体如何驱动酶催化的更好理解。这反过来将导致如何利用纳米晶体结构和性质的巨大可调性来使其适应复杂的、多步骤光驱动化学的设计原则。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。