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Tracking Brownian motion in three dimensions and characterization of individual nanoparticles using a fiber-based high-finesse microcavity

Kohler, Larissa; Mader, Matthias; Kern, Christian; Wegener, Martin; Hunger, David

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 SiO2 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.

Verlagsausgabe §
DOI: 10.5445/IR/1000139630
Veröffentlicht am 05.11.2021
Cover der Publikation
Zugehörige Institution(en) am KIT Physikalisches Institut (PHI)
Karlsruhe School of Optics & Photonics (KSOP)
Institut für Quantenmaterialien und -technologien (IQMT)
Institut für Angewandte Physik (APH)
Institut für Nanotechnologie (INT)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2021
Sprache Englisch
Identifikator ISSN: 2041-1723
KITopen-ID: 1000139630
HGF-Programm 47.11.05 (POF IV, LK 01) Towards Quantum and Neuromorphic Computing Functionalities
Erschienen in Nature Communications
Verlag Nature Research
Band 12
Heft 1
Seiten Article no: 6385
Vorab online veröffentlicht am 04.11.2021
Nachgewiesen in Web of Science
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