QuSeC-TAQS: Optically Hyperpolarized Quantum Sensors in Designer Molecular Assemblies

该项目将开发和演示在金属-有机骨架(MOF)分子组装的有机连接物组件中实现量子传感的方法。这项工作将通过建立模型来促进科学的进步，这些模型揭示了MOF的合成参数如何决定量子相干和其他支持其用作传感器的性质。通过这种新发现的理解，研究人员将能够设计出具有优化的量子传感性能的MOF设计，从而建立基于MOF的新型量子传感工具，这些工具立即适用于通用化学传感和量子信息科学(QIS)的基础研究，性能与现有工具相当或更高。除了一般用途，这些基于MOF的量子传感器将作为一种新的强大手段来询问和表征MOF本身，将产生进一步的影响；由于MOF在催化、碳捕获、能量储存和体外生化传感等领域具有广泛的变革应用潜力，这一新型表征工具有望加速应用MOF造福社会的研究。该项目还将有助于扩大对科学教育和科学工作人员的参与。这个团队将让本科生研究人员参与该项目的所有方面，并通过将数据和设计应用到课程材料中来扩大研究活动的教育影响。此外，该团队将建立一个导师项目，通过加州大学伯克利分校化学学院的量子力学课程为社区大学转学学生(主要是第一代)提供支持，该团队将利用每个项目的成果，向旧金山湾区以本科生为主的机构开展外联活动。该项目将基于MOF中的超极化核自旋开发设计量子传感器平台。这种新的自下而上的方法利用MOF的能力来维持原子上精确的3D量子传感器阵列，并对传感器间距、晶体拓扑、浓缩和传感器间耦合进行精细的综合控制。此外，MOF的高内表面积及其由此产生的吸收客体分子的能力将产生比传统方法具有更高的灵敏度和分辨率的体作为表面的量子传感器。MOF中的有机连接体元素可以容纳光学可极化电子，这些电子可以使自旋极化转移到MOF结构本身或客体分子中的周围核自旋。皮阿霍伊最近证明了超极化核自旋的长达90秒的自旋相干寿命，这将使这些原子核能够作为高灵敏度的磁强计，并通过传递核磁共振光谱数据作为量子化学传感器。该团队将结合一系列参数的自下而上的MOF合成，结合材料项目开发的电子和振动现象的第一性原理计算模型，以及实验光谱和其他表征数据，以确定合成参数对所得MOF的物理、化学和量子相干特性的影响，以优化传感平台。加州大学伯克利分校最近开发的独特仪器将允许在不同温度和磁场下通过核磁共振和电子顺磁共振(EPR)进行相干测量。该项目还将研究2D MOF和插层化合物作为风险缓解措施，并更深入地了解影响一致性和传感器性能的因素。该团队基于MOF的量子传感方法将比目前依靠表面附近的电子自旋进行传感的方法(例如NV中心)具有典型性的进步：MOF的高孔隙率和可调的化学亲和力将允许整个材料块有效地执行传感，而与晶体取向无关将允许将传感器部署到感兴趣的位置。以原子精度在3D中排列量子传感器，并通过合成控制其拓扑、浓缩和传感器间耦合的能力，为量子传感的“设计者”平台开辟了道路。在MOF中使用核自旋超极化，以及利用核自旋获得的长相干时间，将进一步有助于提高灵敏度和传感分辨率，实现变革性应用的目标。该团队预计，这些传感器将能够确定MOF主客体化学过程中的物理吸附和合作结合机制，从而产生用于碳捕获和能量储存的新的优化材料。这些量子传感器在生物学中的应用可能包括使用超极化的13CO2分子作为体内pH化学传感器或体外氧化应激传感器。这一奖项反映了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。

This project will develop and demonstrate methods which implement quantum sensing in the organic linker components of metal-organic framework (MOF) molecular assemblies. This work will serve to promote the progress of science by producing models which reveal how the synthesis parameters of MOFs determine the quantum coherence and other properties underpinning their use as sensors. Through this newfound understanding, researchers will be able to engineer MOF designs with optimized quantum sensing performance and thereby establish novel MOF-based quantum sensing tools which are immediately applicable both for general-purpose chemical sensing and for fundamental research in quantum information science (QIS), with performance equal or superior to existing tools. Beyond generic uses, these MOF-based quantum sensors will have further impact as a new and powerful means to interrogate and characterize the MOFs themselves; as MOFs have broad potential for transformative applications across catalysis, carbon capture, energy storage, and ex-vivo biochemical sensing, among other fields, this novel characterization tool is poised to accelerate research which applies MOFs for the benefit of society. This project will also help to broaden participation in science education and the science workforce. This team will involve undergraduate researchers in all aspects of the project, and extend the educational impact of research activities by adapting data and designs into course materials. Further, this team will institute a mentorship project where they support community college transfer students (largely first generation) through quantum mechanics courses in UC Berkeley’s College of Chemistry, and the team will perform outreach to predominantly undergraduate institutions in the San Francisco Bay Area, drawing upon this project’s outputs in each case.This project will develop designer quantum sensor platforms based on “hyperpolarized” nuclear spins in MOFs. This novel bottom-up approach leverages the ability of MOFs to maintain atomically precise 3D arrays of quantum sensors, with fine synthetic control of sensor spacing, crystal topology, enrichment, and inter-sensor coupling. Moreover, the high internal surface area of MOFs and their resultant ability to imbibe guest molecules will yield “bulk-as-a-surface” quantum sensors with far greater sensitivity and resolution for chemo-sensing than conventional approaches. Organic linker elements in MOFs can host optically polarizable electrons which can be made to transfer spin polarization to surrounding nuclear spins either in the MOF structure itself or in guest molecules. The long ~90s spin coherence lifetimes of hyperpolarized nuclear spins recently demonstrated by PI Ajoy will enable these nuclei to serve as highly sensitive magnetometers and as quantum chemical sensors by relaying nuclear magnetic resonance (NMR) spectral data. The team will combine bottom-up synthesis of MOFs across a range of parameters, first principles computational models of electronic and vibrational phenomena developed in concert with the Materials Project, and experimental spectroscopic and other characterization data to determine the impact of synthetic parameters on the physical, chemical, and quantum coherence properties of the resulting MOF to optimize sensing platforms. Unique instrumentation recently developed in UC Berkeley will allow coherence measurements via NMR and electron paramagnetic resonance (EPR) at various temperatures and magnetic fields. This project will also investigate 2D MOFs and intercalation compounds as risk mitigation and to gain deeper insights into factors impacting coherence and sensor performance. This team's quantum sensing approach based on MOFs will introduce a paradigmatic advance over current methods (e.g. NV centers) that rely on electronic spins near surfaces for sensing: the high porosity and tunable chemical affinity of MOFs will allow the entire material bulk to usefully perform sensing, while independence from crystal orientation will allow deployment of sensors to locations of interest. The ability to array quantum sensors in 3D with atomic precision and control their topology, enrichment, and inter-sensor coupling through synthesis opens avenues for “designer” platforms for quantum sensing. The use of nuclear spin hyperpolarization in MOFs and the long coherence times attainable with nuclear spins will further aid sensitivity and sensing resolution toward the goal of transformative applications. The team anticipates these sensors will allow determination of the physisorption and cooperative binding mechanisms central to MOF host-guest chemistries, thereby yielding new optimized materials for carbon capture and energy storage. Applications of these quantum sensors in biology may include employing hyperpolarized 13CO2 molecules as in-vivo pH chemical sensors, or oxidative stress sensors ex-vivo.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.