TY - JOUR
T1 - Single-Particle Dynamic Light Scattering
T2 - Shapes of Individual Nanoparticles
AU - Guerra, Luis F.
AU - Muir, Tom W.
AU - Yang, Haw
N1 - Funding Information:
This research was supported by a grant from the Gordon and Betty Moore Foundation (4741) and by the National Science Foundation Graduate Research Fellowship Program under Grant DGE-1656466 (to L.F.G.). The authors acknowledge the use of Princeton’s Imaging and Analysis Center, which is partially supported by the Princeton Center for Complex Materials, a National Science Foundation (NSF)-MRSEC program (DMR-1420541).
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/8/14
Y1 - 2019/8/14
N2 - Metallic nanoparticles (MNPs) are prevalent in modern nanotechnologies due to their unique optical properties, chemical and photostability, and ease of manipulation. In particular, many recent advances have highlighted the importance of fundamentally understanding dynamic reconfiguration in MNP morphologies and compositions. Techniques to measure the shape of a single particle are lacking, however, often requiring immobilization, extensive numerical simulations, and irreversible alterations of the particle or its environment. In this work, we introduce "single-particle dynamic light scattering" (SP-DLS) as a far-field technique capable of analyzing the shape of individual, freely diffusing MNPs. Assuming symmetric-top rotors for MNPs and passively confining them to the focal volume of a dark-field microscope for long-term observation, we directly relate polarization dynamic fluctuations in the scattered light to the relative difference between the nondegenerate axes of individual particles. Our results show remarkable agreement with transmission electron microscopy analyses of the same population and allow for unprecedented measurements of the extent of prolate or oblate asphericity of nominally spherical MNPs in solution where the current implementation affords an asphericity detection limit of ∼2.5% assuming a 10% relative error. SP-DLS should serve as a powerful, nondestructive technique for characterizing the shapes of individual MNPs and other nanostructures.
AB - Metallic nanoparticles (MNPs) are prevalent in modern nanotechnologies due to their unique optical properties, chemical and photostability, and ease of manipulation. In particular, many recent advances have highlighted the importance of fundamentally understanding dynamic reconfiguration in MNP morphologies and compositions. Techniques to measure the shape of a single particle are lacking, however, often requiring immobilization, extensive numerical simulations, and irreversible alterations of the particle or its environment. In this work, we introduce "single-particle dynamic light scattering" (SP-DLS) as a far-field technique capable of analyzing the shape of individual, freely diffusing MNPs. Assuming symmetric-top rotors for MNPs and passively confining them to the focal volume of a dark-field microscope for long-term observation, we directly relate polarization dynamic fluctuations in the scattered light to the relative difference between the nondegenerate axes of individual particles. Our results show remarkable agreement with transmission electron microscopy analyses of the same population and allow for unprecedented measurements of the extent of prolate or oblate asphericity of nominally spherical MNPs in solution where the current implementation affords an asphericity detection limit of ∼2.5% assuming a 10% relative error. SP-DLS should serve as a powerful, nondestructive technique for characterizing the shapes of individual MNPs and other nanostructures.
KW - 3D tracking
KW - Metallic nanoparticle
KW - plasmonic
KW - rotational diffusion
KW - single-particle spectroscopy
KW - translational diffusion
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U2 - 10.1021/acs.nanolett.9b02066
DO - 10.1021/acs.nanolett.9b02066
M3 - Article
C2 - 31272153
AN - SCOPUS:85070536644
VL - 19
SP - 5530
EP - 5536
JO - Nano Letters
JF - Nano Letters
SN - 1530-6984
IS - 8
ER -