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3D Spectroscopic Tracking of Individual Brownian Nanoparticles during Galvanic Exchange

Soft Condensed Matter 2022-09-23 v1 Chemical Physics Optics

Abstract

Monitoring chemical reactions in solutions at the scale of individual entities is challenging: single particle detection requires small confocal volumes which are hardly compatible with Brownian motion, particularly when long integration times are necessary. Here, we propose a real-time (10 Hz) holography-based nm-precision 3D tracking of single moving nanoparticles. Using this localization, the confocal collection volume is dynamically adjusted to follow the moving nanoparticle and allow continuous spectroscopic monitoring. This concept is applied to the study galvanic exchange in freely-moving collo{\"i}dal silver nanoparticles with gold ions generated in-situ. While the Brownian trajectory reveals particle size, spectral shifts dynamically reveal composition changes and transformation kinetics at the single object level, pointing at different transformation kinetics for free and tethered particles.

Keywords

Cite

@article{arxiv.2209.11167,
  title  = {3D Spectroscopic Tracking of Individual Brownian Nanoparticles during Galvanic Exchange},
  author = {Minh-Chau Nguyen and Pascal Berto and Fabrice Valentino and Jean-François Lemineur and Jean-Marc Noel and Frédéric Kanoufi and Gilles Tessier},
  journal= {arXiv preprint arXiv:2209.11167},
  year   = {2022}
}

Comments

ACS Nano, American Chemical Society, 2022