UMR 5182

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Hybrid organic-gold nanoparticles

F. Lerouge, F. Chaput, S. Parola, C. Andraud, P. Baldeck, N. Lascoux

Gold nanoshellsGold nano-shells: transparent plasmonic nano-container

FDTD calculation on Gold nanoshellsFD-TD calculation on Gold nano-shells

We designed nanoplatforms for dyes transport in biological media in the form of nanocarriers, consisting in either chromophores encapsulated in the liquid core of gold shells (Nanoletter 2011, 11 (5), 2043) conferring high photostability and brightness, or shells of luminescent polymers grafted on gold nano-spheres, -bipyramids or -stars which could be used to load therapeutic molecules before triggering the cell death with a similar efficiency of the polymer conjugate alone, but with advantage of high loading of photosensitizers (70000/particle) combined with high efficiency (concentration in the picomolar range for efficient PDT). We were able to optimize the structures and observe the first efficient emission enhancement with anisotropic nanoparticles such as bipyramids and stars. (Biomaterials 2013, 34, 8344; Nanoscale 2014, 6, 5138).

Bipyramid preparation

Bipyramid preparation: seed-mediated growth approach

Spectroscopic properties of Gold bipyramids

Gold bipyramids spectrscopic properties

We will continue to study the effects of strong coupling between fluorescent organic molecules and gold nanoparticules. In optimized coupling geometries, nanoparticules act as efficient mediators between the electromagnetic far field (excitation and emission) and molecules. Enhanced excitation fields, and shorter excited-state lifetimes lead to improved fluorescence properties of molecules, i.e. enhanced brightness, higher fluorescence quantum yield, and improved photobleaching resistance.

Fluorescent enhancement

Fluorescence enhancement with Gold nano-bipyramids

We will pursue our study on the effect of molecular direct grafting on nonspherical gold nanoparticules (bipyramids, nanostars,..), and on molecular inclusion inside noncristalline naoparticules (collaboration with D. Avnir, Jerusalem).

fluorescent polymer on gold nanoparicles

Fluorescent polymer grafted on Gold NPs