Topic coordinator: Rodolphe Jaffiol

Summary

Since 2006, we have been developing techniques based on fluorescence spectroscopy and imaging to study living cells. Our ambition is to propose different tools, allowing quantitative analysis at single cell level. Single molecule spectroscopy such as FCS (Fluorescence Correlation Spectroscopy) in diffracted limited and in sub-diffracted volume is employed to probe diffusion process at the nanoscale on cell membrane. Fluorescence nanoscopy, such as variable-angle Total Internal Reflection Fluorescence (vaTIRF) and Non-radiative Excitation Fluorescence (NEF), are used to investigate membrane/substrate interactions and cell adhesion.

Keywords: Single molecule, Fluorescence Correlation Spectroscopy (FCS), fluorescence nano-imaging, super-resolution, Förster Resonant Energy Transfer (FRET), Total Internal Reflection Fluorescence (TIRF), Cell adhesion and migration, membrane fluidity and organization.

Research highlights by keywords

Single nano-object spectroscopy

Accordion content

Nano-photochemistry and energy transfer

Plasmonics

Pictured are experimental images of electromagnetic resonances in an optical antenna based on a fractal-like design, the Cayley tree. The bottom image shows the topography of the structure as seen in scanning transmission electron microscopy. This simple iterative design, combined with the use of aluminum as the antenna material, yields a broadband operating range for the antenna, spanning energies from thermal radiation up to ultraviolet. The spatial distribution of the electromagnetic resonances inside the antenna is directly imaged using electron-energy spectroscopy (EELS), a powerful technique yielding nanoscale resolution. EELS maps of four different resonances are pictured, with increasing energies from top to bottom. Each image maps a 900 nm times 900 nm area.

Aluminum Cayley trees as scalable, broadband, multiresonant optical antennas, T. Simon, X. Li, J. Martin, D. Khlopin, O. Stéfan, M. Kociak, D. Gérard, Proc. Natl. Acad. Sci. U.S.A. 119, e2116833119 (2022)

Optical forces

Accordion content

Current research projects and related applications

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