JEOL Ltd., Akishima, Tokyo196-8558, Japan.
RIKEN-JEOL Collaboration Center, Yokohama, Kanagawa230-0045, Japan.
Chem Rev. 2023 Feb 8;123(3):918-988. doi: 10.1021/acs.chemrev.2c00197. Epub 2022 Dec 21.
Solid-state NMR spectroscopy is one of the most commonly used techniques to study the atomic-resolution structure and dynamics of various chemical, biological, material, and pharmaceutical systems spanning multiple forms, including crystalline, liquid crystalline, fibrous, and amorphous states. Despite the unique advantages of solid-state NMR spectroscopy, its poor spectral resolution and sensitivity have severely limited the scope of this technique. Fortunately, the recent developments in probe technology that mechanically rotate the sample fast (100 kHz and above) to obtain "solution-like" NMR spectra of solids with higher resolution and sensitivity have opened numerous avenues for the development of novel NMR techniques and their applications to study a plethora of solids including globular and membrane-associated proteins, self-assembled protein aggregates such as amyloid fibers, RNA, viral assemblies, polymorphic pharmaceuticals, metal-organic framework, bone materials, and inorganic materials. While the ultrafast-MAS continues to be developed, the minute sample quantity and radio frequency requirements, shorter recycle delays enabling fast data acquisition, the feasibility of employing proton detection, enhancement in proton spectral resolution and polarization transfer efficiency, and high sensitivity per unit sample are some of the remarkable benefits of the ultrafast-MAS technology as demonstrated by the reported studies in the literature. Although the very low sample volume and very high RF power could be limitations for some of the systems, the advantages have spurred solid-state NMR investigation into increasingly complex biological and material systems. As ultrafast-MAS NMR techniques are increasingly used in multidisciplinary research areas, further development of instrumentation, probes, and advanced methods are pursued in parallel to overcome the limitations and challenges for widespread applications. This review article is focused on providing timely comprehensive coverage of the major developments on instrumentation, theory, techniques, applications, limitations, and future scope of ultrafast-MAS technology.
固态核磁共振波谱学是最常用的技术之一,用于研究各种化学、生物、材料和制药系统的原子分辨率结构和动力学,这些系统跨越多种形态,包括结晶态、液晶态、纤维态和无定形态。尽管固态核磁共振波谱学具有独特的优势,但它的光谱分辨率和灵敏度较差,严重限制了该技术的应用范围。幸运的是,近年来探头技术的发展使得样品能够以 100 kHz 及以上的速度快速旋转,从而获得具有更高分辨率和灵敏度的“类似溶液”的固体 NMR 谱,为开发新型 NMR 技术及其在研究包括球状和膜相关蛋白、自组装蛋白聚集体(如淀粉样纤维)、RNA、病毒组装体、多晶型药物、金属有机骨架、骨材料和无机材料在内的多种固体方面的应用开辟了许多途径。虽然超快速 MAS 仍在不断发展,但该技术具有样品量小、射频要求高、较短的循环延迟时间以实现快速数据采集、质子检测的可行性、质子光谱分辨率和极化转移效率的提高以及单位样品的高灵敏度等显著优势,这一点在文献报道的研究中得到了证明。尽管对于某些系统来说,非常低的样品量和非常高的射频功率可能是限制因素,但这些优势激发了固态 NMR 对越来越复杂的生物和材料系统的研究。随着超快速 MAS NMR 技术在多学科研究领域的广泛应用,仪器设备、探头和先进方法的进一步发展也在同步进行,以克服广泛应用的限制和挑战。本文综述聚焦于提供固态核磁共振波谱学领域的重大发展的及时、全面的综述,包括仪器设备、理论、技术、应用、局限性和未来发展前景。