Photodissolution of ultrasmall maghemite nanoparticles
Dmitrii Tsiurko1, Ekaterina Moiseeva1, Sergei German1,2, Daria Terentyeva1, Arsen Zotov3, Alina Platonova1,3, Vsevolod Skribitsky4, Alexey Lipengolts4, Zhanna Bochkova1,5, Semen Domarev6, Nadezhda Brazhe5, Anna Orlova6, Dmitry Gorin1,2.
1Center for Photonic Science and Engineering, Skolkovo Institute of Science and Technology, 143026 Moscow, Russia | 2Central University, 125047 Moscow,
Russia | 3A.M. Prokhorov Institute of General Physics of the Russian Academy of Sciences (IGF RAS), 119991 Moscow, Russia | 4N.N. Blokhin National Med-
ical Research Center of Oncology, 115522 Moscow, Russia 5Faculty of Physics, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia | 6International Research and Education Centre for Physics of
Nanostructures, ITMO University, 197101 Saint Petersburg, Russia |
Abstract
The controlled release of iron ions from nanoparticles is critical for biomedical applications, including ferroptosis induction. Here, we demonstrate near-complete (~100%) photodissolution of 4 nm maghemite (γ-Fe₂O₃) nanoparticles under visible light (460 nm and 530 nm) mediated by citrate ligands. Using real-time dynamic light scattering (DLS) and spectrophotometry, we reveal a two-stage dissolution process: rapid iron ions release followed by slowdown upon nanoparticle aggregation. Strikingly, solution conductivity decreases linearly with Fe-ion release (1/conversion ∝ conductivity), providing the first experimental evidence of charge-carrier immobilization during photodissolution. Dark controls show ~15% conversion of dissolution, confirming light dependence. This system achieves spatiotemporal control of iron delivery with tunable kinetics (80 min for 460 nm vs. 240 min for 530 nm), offering a platform for on-demand ferroptosis studies. The inverse conductivity-conversion relationship establishes a novel real-time dissolution marker, potentially transferable to other redox-active nanomaterials. It was established how the citric acid concentration governs the balance between dissolution and aggregation, revealing its dual role as both a stabilizer and a chelator. This work advances our understanding of light-driven nanomaterial transformations while establishing practical tools for their control and monitoring.
This work was supported by Russian Science Foundation (RSF) grant No 26-14-00273.
Speaker
Dmitrii Tsiurko
Skolkovo Institute of Science and Technology
Russian Federation
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