Development of Cavity-Enhanced Single-Molecule Electronic and Vibrational Spectroscopy for Mechanistic Studies of Biomolecules

用于生物分子机理研究的腔增强单分子电子和振动光谱学的发展

• 批准号: 10251006
• 负责人: Randall H Goldsmith
• 金额: $ 28.04万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-05 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10251006
• 关键词: Biochemical; Biological; Chemicals; Cobalt; Complex; Coupling; Development; Devices; Diagnostic; Dyes; Environment; Evaluation; Fiber; Film; Fluorescence; Geometry; Glass; In Vitro; Individual; Investigation; Label; Learning; Light; Measurement; Metals; Methods; Microbubbles; Molecular; Monitor; Optics; Performance; Polymers; Positioning Attribute; Production; Property; Pump; Raman Spectrum Analysis; Sampling; Series; Signal Transduction; Specificity; Spectrum Analysis; Surface; System; Techniques; Technology; Temperature; Testing; Thermometers; Time; Vitamin B 12; absorption; aqueous; biomaterial compatibility; biophysical techniques; chemical bond; chemical reaction; design; indexing; insight; instrumentation; metalloenzyme; molecular dynamics; nanoparticle; oxidation; particle; photonics; plasmonics; silicon nitride; single molecule; tool; vibration

Development of Cavity-Enhanced Single-Molecule Electronic and Vibrational Spectroscopy for Mechanistic Studies of Biomolecules Single-molecule (SM) measurements are a powerful mechanistic tool because they allow multi-step unsynchro- nized dynamics to be directly observed. However, most SM observations rely on fluorescence, which lacks the sensitivity to determine oxidation state, the chemical specificity to elucidate distortion of a particular chemical bond, and requires a fluorescent label. Such information would revolutionize how biochemical mechanisms are determined and could be provided by a method of performing electronic absorption and vibrational spectroscopy on single operational biomolecules. However, surface-enhanced Raman spectroscopy (SERS) is not is suited for probing complex biomolecules, as the method requires intimate contact between the part of the biomolecule to be probed (which may be at the interior), and a metal surface. Similarly, methods exist for performing SM elec- tronic absorption spectroscopy but they lack the required sensitivity or biocompatibility for biomolecules. Thus, a new method is needed to allow SM investigations of in vitro molecular dynamics for mechanistic investigations. We propose the use of optical microcavities as platforms for ultrasensitive SM electronic and vibrational spectroscopy. In one geometry, microcavities are used as highly sensitive thermometers, capable of detecting the heat dissipated by non-fluorescent molecules upon photoexcitation. In this way, non-fluorescent and potentially even weakly absorbing spectral features, such as those diagnostic of the coordination environment of a metal- loenzyme can be elucidated. In a second complimentary geometry we take advantage of the Purcell Effect, which can significantly enhance scattering rates in optical microcavities with small mode volumes and high Quality factors. While SERS requires essentially Van der Waals contact with a plasmonic surface, the microcavity en- hancement can act at a distance of up to ~100 nm from a dielectric surface, making it suitable for probing bio- molecules without significant perturbation. We have now demonstrated the core concepts behind these two strat- egies. In Specific Aims 1-3, we will bring online and evaluate three new microcavity systems that promise to significantly enhance our measurement capacity enough to lay a concrete path to biomedical applications: planar silicon nitride ring resonators (SA 1), fiber Fabry-Perot microcavities (SA 2), and silicon nitride nanobeams (SA3). In all cases we will perform spectroscopy on a series of particles and molecules of increasing challenge, pushing toward the monitoring of a single working metalloenzyme. Supporting calculations suggest that these new resonator geometries will increase our molecular signals by orders of magnitude. Our long-term objective is to bring a new, highly informative, and even disruptive biophysical technique to bear on biological molecules to understand how they operate, change in time, are regulated, and fail.

开发腔体增强的单分子电子和振动光谱法 生物分子的机械研究 单分子（SM）测量是一种强大的机械工具，因为它们允许多步不同步 直接观察到的动力学。但是，大多数SM观察都取决于缺乏的荧光 确定氧化态的敏感性，阐明特定化学化学的化学特异性 键，需要荧光标签。这些信息将彻底改变生化机制 确定并可以通过执行电子吸收和振动光谱的方法提供 在单一作战生物分子上。但是，表面增强的拉曼光谱法（SER）不适合 探测复杂的生物分子，因为该方法需要在生物分子的一部分与 探测（可能在内部）和金属表面。同样，存在执行SM Elec-的方法 扭曲吸收光谱，但缺乏对生物分子的敏感性或生物相容性。因此， 需要一种新方法来允许对体外分子动力学进行SM研究以进行机理研究。 我们建议将光学微腔用作超敏感的SMETROC和振动的平台 光谱法。在一个几何形状中，微腔用作高度敏感的温度计，能够检测 光激发后非荧光分子散发的热量。这样，非荧光和潜在的 即使是弱吸收的光谱特征，例如诊断金属的协调环境的光谱特征 可以阐明叶酶。在第二个免费几何形状中，我们利用了Purcell效应， 可以显着提高具有较小模式和高质量的光学微腔的散射速率 因素。尽管SERS基本上需要范德华与等离子体表面接触，但微腔内 Hancement可以在距介电表面的距离内作用约100 nm，因此适合探测生物 分子没有明显的扰动。我们现在已经证明了这两个阶层背后的核心概念 耶稣。在特定的目标1-3中，我们将在线携带并评估三个新的微腔系统，以确保有望 显着增强了我们的测量能力足以为生物医学应用奠定混凝土路径：平面 氮化硅环谐振器（SA 1），纤维Fabry-Perot微腔（SA 2）和氮化硅纳米梁 （SA3）。在所有情况下 向监测单个工作金属酶。支持计算表明这些 新的谐振器几何形状将通过数量级增加我们的分子信号。我们的长期目标 是为了携带一种新的，高度的信息，甚至是破坏性的生物物理技术来实现生物分子 了解它们的操作方式，时间变化，受到监管和失败。