Bulky Counterions: Enhancing the Two-Photon Excited Fluorescence of Gold Nanoclusters

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Nonlinear Refraction and Absorption of Ag 29 Nanoclusters: Evidence for Two-Photon Absorption Saturation

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Ag31(SG)19 and Ag15(SG)11

We report a simple synthesis of silver:glutathione (Ag:SG) clusters using a cyclic reduction under oxidative conditions. Two syntheses are described which lead to solutions containing well-defined Ag31(SG)19 and Ag15(SG)11 clusters that have been characterized by mass spectrometry. The optical properties of silver:glutathione (Ag:SG) cluster solutions have been investigated experimentally. In particular, the solution containing Ag15(SG)11 clusters shows a bright and photostable emission. For Ag31(SG)19 and Ag15(SG)11 clusters, the comparison of experimental findings with DFT and TDDFT calculations allowed us to reveal the structural and electronic properties of such low nuclearity liganded silver clusters

Ag31(SG)19 and Ag15(SG)11

We report a simple synthesis of silver:glutathione (Ag:SG) clusters using a cyclic reduction under oxidative conditions. Two syntheses are described which lead to solutions containing well-defined Ag31(SG)19 and Ag15(SG)11 clusters that have been characterized by mass spectrometry. The optical properties of silver:glutathione (Ag:SG) cluster solutions have been investigated experimentally. In particular, the solution containing Ag15(SG)11 clusters shows a bright and photostable emission. For Ag31(SG)19 and Ag15(SG)11 clusters, the comparison of experimental findings with DFT and TDDFT calculations allowed us to reveal the structural and electronic properties of such low nuclearity liganded silver clusters

Zwitterion functionalized gold nanoclusters for multimodal near infrared fluorescence and photoacoustic imaging

International audienceGold nanoclusters (Au NCs) are an emerging type of theranostic agents combining therapeutic and imaging features with reduced toxicity. Au NCs stabilized by a zwitterion ligand with a fine control of the metal core size and the ligand coverage were synthesized by wet chemistry. Intense fluorescence signal is reported for the highest ligand coverage whereas photoacoustic signal is stronger for the largest metal core. The best Au NCs candidate with an average molecular weight of 17 kDa could be detected with high sensitivity on a 2D-NIR imaging instrument (LOD = 2.3 µM) and by photoacoustic imaging. In vitro and in vivo experiments demonstrate an efficient cell uptake in U87 cell lines, a fast renal clearance (t 1/2 α = 6.5±1.3 min) and a good correlation between near 2 infrared fluorescence and photoacoustic measurements to follow the early uptake of Au NCs in liver

pH-Induced transformation of ligated Au 25 to brighter Au 23 nanoclusters

Thiolate-protected gold nanoclusters have recently attracted considerable attention due to their size-dependent luminescence characterized by a long lifetime and large Stokes shift. However, the optimization of nanocluster properties such as the luminescence quantum yield is still a challenge. We report here the transformation of Au25Capt18 (Capt labels captopril) nanoclusters occurring at low pH and yielding a product with a much increased luminescence quantum yield which we have identified as Au23Capt17. We applied a simple method of treatment with HCl to accomplish this transformation and we characterized the absorption and emission of the newly created ligated nanoclusters as well as their morphology. Based on DFT calculations we show which Au nanocluster size transformations can lead to highly luminescent species such as Au23Capt17

Etude de microcristaux organiques luminescents (préparation assistée par des dendrimères)

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Sizing protein-templated gold nanoclusters by time resolved fluorescence anisotropy decay measurements.

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