Ultrafast Dynamics of Solute Molecules Probed by Resonant Optical Kerr Effect Spectroscopy
Ultrafast Dynamics of Solute Molecules Probed by Resonant Optical Kerr Effect Spectroscopy
复制标题
共振光学克尔效应光谱探测溶质分子的超快动力学
DOI：
10.1021/acs.jpclett.2c02461
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发表时间：
2022
影响因子：
4.4
通讯作者：
Thomas W. Ebbesen
中科院分区：
文献类型：
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作者：
Soh Kushida;Kuidong Wang;Cyriaque Genet;Thomas W. Ebbesen
流体中的超快分子动力学在许多生物和化学系统中非常重要。尽管已经通过各种方法探索了散装液体中的这种动力学，但揭示溶剂化溶质动力学的实验工具仍然有限。在这项工作中，我们开发了共振光学克尔效应光谱（ROKE），它是光学克尔效应光谱的类似物，可测量溶液中稀溶质的重新取向弛豫。通过在溶质的共振吸收带处调节泵浦和探针波长，可以轻松地将溶质的时间响应与溶剂的可忽略信号区分开来。 ROKE 的外差检测能够确定重定向弛豫时间常数，精度为 2.6%。信噪比足够高（平均~26.7），即使从 10 μM 溶液中也能获得足够的信号。因此，ROKE 是一个强大的工具，可以在广泛的应用中以高灵敏度研究溶质动力学。
Ultrafast molecular dynamics in fluids is of great importance in many biological and chemical systems. Although such dynamics in bulk liquids has been explored by various methods, experimental tools that unveil the dynamics of solvated solutes are limited. In this work, we have developed resonant optical Kerr effect spectroscopy (ROKE), which is an analogue of optical Kerr effect spectroscopy that measures the reorientational relaxation of a dilute solute in solution. By adjusting the pump and probe wavelengths at the resonant absorption band of a solute, the time response of the solute was distinguished easily from the negligible signal of the solvent. The heterodyne detection of ROKE enables the determination of reorientational relaxation time constants with an accuracy of 2.6%. The signal-to-noise ratio was high enough (average ∼26.7) to obtain an adequate signal from even a 10 μM solution. Thus, ROKE is a powerful tool to study solute dynamics with high sensitivity in a broad range of applications.