Title: Ligand impact on reactive oxygen species generation of Au10 and Au25 nanoclusters upon one- and two-photon excitation
Authors: Hussein Fakhouri, Martina Perić Bakulić, Issan Zhang, Hao Yuan, Dipankar Bain, Fabien Rondepierre, Pierre-François Brevet, Željka Sanader Maršić, Rodolphe Antoine, Vlasta Bonačić-Koutecký, Dusica Maysinger
DOI: https://doi.org/10.1038/s42004-023-00895-5
Date: 22/05/2024
Working Group: WG3
Grant Period: 1
Grant Period Goal (number): GAPG-4
Covered deliverables from the MoU (number): 3.2, 2.6.3
Countries involved: Croatia, France, Canada
Number of female/young/ITC coauthors: 5
Abstract: In photodynamic therapy (PDT), light-sensitive photosensitizers produce reactive oxygen species (ROS) after irradiation in the presence of oxygen. Atomically-precise thiolate-protected gold nanoclusters are molecule-like nanostructures with discrete energy levels presenting long lifetimes, surface biofunctionality, and strong near-infrared excitation ideal for ROS generation in PDT. We directly compare thiolate-gold macromolecular complexes (Au10) and atomically-precise gold nanoclusters (Au25), and investigate the influence of ligands on their photoexcitation. With the ability of atomically-precise nanochemistry, we produce Au10SG10, Au10AcCys10, Au25SG18, and Au25AcCys18 (SG: glutathione; AcCys: N-acetyl-cysteine) fully characterized by high-resolution mass spectrometry. Our theoretical investigation reveals key factors (energetics of excited states and structural influence of surface ligands) and their relative importance in singlet oxygen formation upon one- and two-photon excitation. Finally, we explore ROS generation by gold nanoclusters in living cells with one- and two-photon excitation. Our study presents in-depth analyses of events within gold nanoclusters when photo-excited both in the linear and nonlinear optical regimes, and possible biological consequences in cells.
