Karlsruher Institut für Technologie, Physikalisches Institut, Wolfgang-Gaede-Str. 1, 76131, Karlsruhe, Germany.
Fakultät für Physik, Ludwig-Maximilians-Universität, Schellingstraße 4, 80799, München, Germany.
Nat Commun. 2021 Nov 4;12(1):6385. doi: 10.1038/s41467-021-26719-5.
The dynamics of nanosystems in solution contain a wealth of information with relevance for diverse fields ranging from materials science to biology and biomedical applications. When nanosystems are marked with fluorophores or strong scatterers, it is possible to track their position and reveal internal motion with high spatial and temporal resolution. However, markers can be toxic, expensive, or change the object's intrinsic properties. Here, we simultaneously measure dispersive frequency shifts of three transverse modes of a high-finesse microcavity to obtain the three-dimensional path of unlabeled SiO nanospheres with 300 μs temporal and down to 8 nm spatial resolution. This allows us to quantitatively determine properties such as the polarizability, hydrodynamic radius, and effective refractive index. The fiber-based cavity is integrated in a direct-laser-written microfluidic device that enables the precise control of the fluid with ultra-small sample volumes. Our approach enables quantitative nanomaterial characterization and the analysis of biomolecular motion at high bandwidth.
溶液中的纳米系统动力学包含了丰富的信息，这些信息与从材料科学到生物学和生物医学应用等多个领域都有关联。当纳米系统被荧光团或强散射体标记时，就有可能跟踪它们的位置，并以高时空分辨率揭示内部运动。然而，标记物可能具有毒性、昂贵，或者改变物体的固有性质。在这里，我们同时测量了一个高精细微腔的三个横向模式的色散频率移动，以获得未标记的 SiO 纳米球的三维路径，时间分辨率为 300μs，空间分辨率低至 8nm。这使我们能够定量确定诸如极化率、流体力学半径和有效折射率等性质。基于光纤的微腔集成在直接激光写入的微流控装置中，该装置能够以超小的样品体积精确控制流体。我们的方法能够实现高通量的纳米材料特性分析和生物分子运动分析。
