Thèse

Jeudi 23 Juillet 2026 à 14h00.

Photoluminescence in Atomically Precise Ligand Protected Metal Nanoclusters: Elucidating Mechanism and Applications in Sensing and Bio-Imaging

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Directeur de thèse / thesis director :
Rodolphe ANTOINE

Membres du jury / jury members :
Corinne CHANEAC. Professeure des Universités, Sorbonne-Université. Rapporteure
Valérie MARCHI. Directrice de Recherche CNRS, Université de Rennes. Rapporteure
David AMANS. Professeur des Universités, Lyon 1 Universite Claude Bernard. Examinateur
Sanjun ZHANG. Professeur des Universités, East China Normal University, Shanghai, China. Examinateur
Isabelle RUSSIER-ANTOINE. Maître de Conférences, Lyon 1 Universite Claude Bernard. Examinatrice
Rodolphe ANTOINE. Directeur de Recherche CNRS, Lyon 1 Universite Claude Bernard. Directeur de thèse

Résumé / Abstract :
Positioned between organometallic complexes and plasmonic nanoparticles, atomically precise metal nanoclusters exhibit discrete electronic structures, ultrasmall size, atomically well-defined structures, and tunable optical properties, particularly photoluminescence in both linear and nonlinear optical regimes, making them attractive candidates for bioimaging and phototherapy. The main objective of this thesis is to elucidate how atomic composition, ligand environment, and biomolecular protection govern both radiative and non-radiative photophysical processes, including photoluminescence, photothermal conversion, and reactive oxygen species generation, and to exploit these properties for optical and biomedical applications.

To achieve this goal, a multidisciplinary approach combining synthesis, structural characterization, mass spectrometry, steady-state and time-resolved spectroscopy, transient absorption, nonlinear optical measurements, and bioimaging techniques was employed. Particular emphasis is placed on establishing the relationships between atomic structure, excited-state dynamics, photophysical properties, and biofunctionalities. This work investigates the photoluminescence mechanism of atomically precise ligand-protected metal nanoclusters, the modulation of nonlinear optical responses through ligand engineering, the structure-dependent non-radiative relaxation pathways responsible for photothermal conversion and reactive oxygen species generation, and representative applications in antibacterial therapy and two-photon fluorescence bioimaging.

During the defense, I will mainly illustrate these research themes through the representative example of protein-directed metal nanoclusters, showing how their synthesis, structural characterization, and excited-state photophysics contribute to understanding their photoluminescence mechanism and enable their application in bioimaging.

Overall, this thesis establishes strong structure–property relationships linking atomically precise structures, excited-state dynamics, photophysical processes, and biofunctionalities in metal nanoclusters. Beyond providing fundamental insights into their optical behavior, this work offers rational design strategies for developing multifunctional metal nanoclusters for imaging, sensing, nonlinear optics, and phototherapy.

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