Publications

2023

• Simple Postsynthesis Thermal Treatment toward High Luminescence Performance of Rare Earth Vanadate Nanoparticles
  
  • Perrella Rafael Vieira
  • Mohammedi Rabei
  • Kuhner Robin
  • Cardone Christophe
  • Larquet Eric
  • Alexandrou Antigoni
  • de Sousa Filho Paulo Cesar
  • Gacoin Thierry
  Crystal Growth & Design, American Chemical Society, 2023, 23 (8), pp.5389-5396. Optical applications of colloidal oxide nanoparticles are often limited by low luminescence efficiencies caused by poor crystallinity and surface quenching. Bulk oxides prepared via conventional high-temperature annealing offer intense luminescence but commonly fail to yield stable colloidal dispersions. Coupling the best of these two situations to afford highly crystalline, dispersible nanoparticles with luminescence performance exceeding bulk solids is still challenging, thus requiring new safe, scalable, and reproducible methodologies. Herein we report a silicate-coating strategy followed by aggregate elimination to recover stable colloids of 40-150 nm single crystalline rare earth vanadates after unprotected annealing (800-1000 °C). Eu3+-doped nanoparticles showed enhanced photostability and ~50% emission quantum yields in water (λexc=280 nm), while Dy3+-, Tm3+-, and Yb3+/Er3+-doped vanadates provided remarkably intense multicolour emissions via downshift or upconversion luminescence. We correlated spectroscopic properties of pristine and annealed solids to microstructural characteristics to explain the superior emission features, opening new perspectives for sensing applications. (10.1021/acs.cgd.3c00308)
  DOI : 10.1021/acs.cgd.3c00308
• Evaluation of Slowfade Diamond as a buffer for STORM microscopy
  
  • Boukhatem Hadjer
  • Durel Beatrice
  • Raimbault Manon
  • Laurent Audrey
  • Olivier Nicolas
  Biomedical optics express, Optical Society of America - OSA Publishing, 2023, 14 (2), pp.550. We study the potential of the commercial mounting medium Slowfade diamond as a buffer for STORM microscopy. We show that although it does not work with the popular far-red dyes typically used for STORM imaging, such as Alexa Fluor 647, it performs really well with a wide variety of green-excited dyes such as Alexa Fluor 532, Alexa Fluor 555 or CF 568. Moreover, imaging can be performed several months after the samples are mounted in this environment and kept in the fridge, providing a convenient way to preserve samples for STORM imaging, as well as to keep calibration samples, for example for metrology or teaching in particular in imaging facilities. (10.1364/BOE.473463)
  DOI : 10.1364/BOE.473463
• Collective cell migration due to guidance-by-followers is robust to multiple stimuli
  
  • Müller Robert
  • Boutillon Arthur
  • Jahn Diego
  • Starruß Jörn
  • David Nicolas B
  • Brusch Lutz
  Frontiers in Applied Mathematics and Statistics, Frontiers Media S.A, 2023, 9, pp.1163583. Collective cell migration is an important process during biological development and tissue repair but may turn malignant during tumor invasion. Mathematical and computational models are essential to unravel the mechanisms of self-organization that underlie the emergence of collective migration from the interactions among individual cells. Recently, guidance-by-followers was identified as one such underlying mechanism of collective cell migration in the embryo of the zebrafish. This poses the question of how the guidance stimuli are integrated when multiple cells interact simultaneously. In this study, we extend a recent individual-based model by an integration step of the vectorial guidance stimuli and compare model predictions obtained for different variants of the mechanism (arithmetic mean of stimuli, dominance of stimulus with largest transmission interface, and dominance of most head-on stimulus). Simulations are carried out and quantified within the modeling and simulation framework Morpheus. Collective cell migration is found to be robust and qualitatively identical for all considered variants of stimulus integration. Moreover, this study highlights the role of individual-based modeling approaches for understanding collective phenomena at the population scale that emerge from cell-cell interactions. (10.3389/fams.2023.1163583)
  DOI : 10.3389/fams.2023.1163583