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Microscopie de nano-objets individuels pour la neurobiologie

Abstract : In this manuscript a new optical method is introduced to detect single metal nanoparticles for biological and biochemical applications. This method called LISNA (Laser Induced Scattering around a NanoAbsorber) takes advantage of absorbing properties of metal nanoparticles near their plasmon resonance.We first show that it can be used on fixed samples such as in in vitro biochemistry experiments. We then show that this technique can also be used efficiently to study dynamic phenomena through two modes. First, it allows to record the trajectories of 2D-diffusing nanoparticles using a triangulation scheme (Single Nanoparticle Photothermal Tracking – SNaPT). We thus could track postsynaptic receptors labelled with 5 nm gold beads on live neurons for several minutes. To characterize the diffusion of faster nanoparticles, we have developed a new approach based on the analysis of signal correlations as nanoparticles go through the detection volume. This method (Absorption Correlation Spectroscopy – ACS) gives precise information about the hydrodynamic radius of the objects that are observed, but should also find interesting applications in live cell studies by giving access to long time scales that are not accessible for standard FCS experiments. Finally, we demonstrate that mitochondria (some absorbing cellular organelles) could be imaged using LISNA on live cells without extrinsic labelling, and the origin of the signal was studied.
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https://tel.archives-ouvertes.fr/tel-00258911
Contributor : David Lasne <>
Submitted on : Tuesday, February 26, 2008 - 9:33:56 AM
Last modification on : Monday, January 22, 2018 - 11:02:02 AM
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  • HAL Id : tel-00258911, version 1

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David Lasne. Microscopie de nano-objets individuels pour la neurobiologie. Biophysique [physics.bio-ph]. Université Sciences et Technologies - Bordeaux I, 2007. Français. ⟨tel-00258911⟩

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