129Xe NMR Relaxation-Based Macromolecular Sensing

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• 作者：Muller D. Gomes ; Phuong Dao ; Keunhong Jeong ; Clancy C. Slack ; Christophoros C. Vassiliou ; Joel A. Finbloom ; Matthew B. Francis ; David E. Wemmer ; Alexander Pines
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：August 10, 2016
• 年：2016
• 卷：138
• 期：31
• 页码：9747-9750
• 全文大小：222K
• 年卷期：0
• ISSN：1520-5126

文摘

We report a ¹²⁹Xe NMR relaxation-based sensing approach that exploits changes in the bulk xenon relaxation rate induced by slowed tumbling of a cryptophane-based sensor upon target binding. The amplification afforded by detection of the bulk dissolved xenon allows sensitive detection of targets. The sensor comprises a xenon-binding cryptophane cage, a target interaction element, and a metal chelating agent. Xenon associated with the target-bound cryptophane cage is rapidly relaxed and then detected after exchange with the bulk. Here we show that large macromolecular targets increase the rotational correlation time of xenon, increasing its relaxation rate. Upon binding of a biotin-containing sensor to avidin at 1.5 μM concentration, the free xenon T₂ is reduced by a factor of 4.