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Updated: Jun 21, 2026

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules
Published on: April 25, 2025
Anisotropy effects on the time-resolved spectroscopy of the acoustic vibrations of nanoobjects
Aurélien Crut1, Paolo Maioli, Natalia Del Fatti
1FemtoNanoOptics Group, Université Lyon 1, CNRS, LASIM, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne, France. acrut@lasim.univ-lyon1.fr
Abstract:
The impact of spherical symmetry breaking and crystallinity on the response of the vibrational acoustic modes of a nanoobject in frequency- and time-domain experiments is investigated using the finite-element analysis method. The results show that introduction of shape anisotropy, i.e., evolution from a nanosphere to a nanorod, modifies the periods of the fundamental radial and quadrupolar modes and leads to activation of a quadrupolar-like mode in time-domain studies. In contrast, crystallinity is shown to have a negligible impact on the breathing mode frequency of a nanosphere formed by a cubic crystal and does not activate any quadrupolar mode. The effect of an anisotropic excitation in time-resolved measurements of a large nanosphere is also discussed.
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