CAREER: Probing Quantum Coherence in Biomolecular Microenvironments via Electron Spin Molecular Quantum Sensors

美国国家科学基金会的量子飞跃计划旨在促进对量子力学在计算、建模、通信和传感等领域的理解和应用。这些领域的创新将满足社会对包括具有精致灵敏度和分辨率的传感器的技术的需求。为了应对这些挑战，分子量子信息科学(QIS)利用合成化学的精细可调性来理解、设计和利用具有可测量和可控制的量子性质的新的分子和材料。这项研究项目旨在开发新的分子系统、模型和协议，用于生物学中的量子传感，以实现原子精确的磁成像。通过该项目构建的分子和生物传感器将用于高灵敏度地研究生物系统中的化学微环境，并了解生物系统和过程中的量子效应。反过来，这项研究利用了一种互惠关系，不仅将开发用于生物应用的量子传感器，还将提高对未来分子QIS在技术设备中应用所需的量子过程的理解。通过该项目的一个教育部分，将开发开放的教育资源，通过扩大和简化接受化学教育和研究的机会，扩大这项工作的影响。这些资源将缓解限制对量子范式的理解和STEM成功的成本障碍。此外，还将开发一项新的研究培训计划，为邻近社区大学的学生提供化学技术，使历史上代表性不足、几乎没有研究经验的学生能够继续从事STEM职业。目前分子量子信息科学(QIS)的研究寻求通过化学合成和光谱表征开发用于计算、通信和传感的量子使能技术。该项目将QIS和生物物理学结合起来，从根本上了解分子内和分子间对退相干动力学的影响，并量化退相干时间的变化，以探测生化微环境。这项研究的目标是发展用于生物学的分子量子传感器，利用电子自旋退相干实现原子精确的磁共振成像。本项目包括四个目标：1)发展基于退相干的量子传感机制的理论/实验描述；2)研究分子量子传感器(Qusor)标记的膜的退相干特性；3)阐明次级球对顺磁金属蛋白活性部位退相干的贡献；以及4)选择性靶向蛋白质特定的Qusor结合。首先，建立了有机分子和低对称性过渡金属络合物的自旋-晶格和自旋-自旋弛豫时间的理论模型，然后将其扩展到大分子体系的计算。其次，将顺磁性有机分子引入到脂质组装体中，用于研究胶束形态和室温下的超快光谱界面。第三，将探索顺磁性金属蛋白及其突变体的退相干动力学，以量化二次球效应的最大距离，提高计算方法的准确性。第四，将合成和组装分子Qusor-Protein复合体，以展示感测特定结合事件的退相干效应。该项目将采用的技术包括化学合成、蛋白质表达和纯化、X射线结晶学、光学和磁谱学以及理论和计算方法。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。

The National Science Foundation’s Quantum Leap initiative seeks to promote understanding and application of quantum mechanics towards areas such as computation, modeling, communication, and sensing. Innovation in these areas will meet societal needs for technologies that include sensors with exquisite sensitivity and resolution. Towards these challenges, molecular Quantum Information Science (QIS) makes use of the fine tunability of synthetic chemistry to understand, design, and utilize new molecules and materials with measurable and controllable quantum properties. This research project aims to develop new molecular systems, models, and protocols for quantum sensing in biology towards the goal of enabling atomically-precise magnetic imaging. The molecular and biological sensors constructed through this project will be used to study chemical micro-environments in biological systems with high sensitivity and to understand quantum effects in biological systems and processes. In turn, this research utilizes a reciprocal relationship that will not only develop quantum sensors for biological applications but will also improve understanding of quantum processes needed for future applications of molecular QIS in technological devices. Through an educational component to this project, open educational resources will be developed to amplify the impact of this work by expanding and simplifying access to chemical education and research. These resources will alleviate cost barriers that limit understanding of the quantum paradigm and success in STEM. Additionally, a new research training program will bedeveloped to provide chemistry techniques to students in a neighboring community college, enabling historically underrepresented students with little to no research experience to continue in STEM careers.Current research in molecular Quantum Information Science (QIS) seeks to develop quantum-enabled technologies for computation, communication, and sensing through chemical synthesis and spectroscopic characterization. This project combines QIS and biophysics to fundamentally understand intramolecular and intermolecular effects on decoherence dynamics and to quantify changes in decoherence times for probing biochemical micro-environments. The goal of this research is the development of molecular quantum sensors for biology towards atomically-precise magnetic resonance imaging using electron spin decoherence. This project contains four objectives: 1) the development of theoretical/experimental descriptions of decoherence-based quantum sensing mechanisms, 2) the investigation of decoherence properties of molecular quantum sensor (qusor)-labeled membranes, 3) the elucidation of secondary sphere contributions to decoherence in paramagnetic metalloprotein active sites, and 4) the selective targeting of protein-specific qusor binding. First, theoretical models for spin-lattice and spin-spin relaxation times will be developed for organic molecules and low-symmetry transition metal complexes, then expanded to computations for macromolecular systems. Second, paramagnetic organic molecules will be introduced into lipid assemblies for studying micellar morphologies and interfaces with ultrafast spectroscopy at room temperature. Third, the decoherence dynamics of paramagnetic metalloproteins and their mutants will be probed to quantify the maximum distance for secondary sphere effects and to improve the accuracy of computational methods. Fourth, molecular qusor-protein complexes will be synthesized and assembled to demonstrate decoherence effects for sensing site-specific binding events. Techniques to be employed for this project include chemical synthesis, protein expression and purification, X-ray crystallography, optical and magnetic spectroscopies, and theoretical and computational methods.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.