Produção Nacional
Revisado por pares
Correlative cellular ptychography with functionalized nanoparticles at the Fe L-edge
2017; Nature Portfolio; Volume: 7; Issue: 1 Linguagem: Inglês
10.1038/s41598-017-04784-5
ISSN2045-2322
AutoresMarcus Gallagher-Jones, Carlos Sato Baraldi Dias, Alan Pryor, Karim Bouchmella, Lingrong Zhao, Yuan Hung Lo, Mateus Borba Cardoso, David A. Shapiro, José A. Rodríguez, Jianwei Miao,
Tópico(s)Advanced Electron Microscopy Techniques and Applications
ResumoAbstract Precise localization of nanoparticles within a cell is crucial to the understanding of cell-particle interactions and has broad applications in nanomedicine. Here, we report a proof-of-principle experiment for imaging individual functionalized nanoparticles within a mammalian cell by correlative microscopy. Using a chemically-fixed HeLa cell labeled with fluorescent core-shell nanoparticles as a model system, we implemented a graphene-oxide layer as a substrate to significantly reduce background scattering. We identified cellular features of interest by fluorescence microscopy, followed by scanning transmission X-ray tomography to localize the particles in 3D, and ptychographic coherent diffractive imaging of the fine features in the region at high resolution. By tuning the X-ray energy to the Fe L-edge, we demonstrated sensitive detection of nanoparticles composed of a 22 nm magnetic Fe 3 O 4 core encased by a 25-nm-thick fluorescent silica (SiO 2 ) shell. These fluorescent core-shell nanoparticles act as landmarks and offer clarity in a cellular context. Our correlative microscopy results confirmed a subset of particles to be fully internalized, and high-contrast ptychographic images showed two oxidation states of individual nanoparticles with a resolution of ~16.5 nm. The ability to precisely localize individual fluorescent nanoparticles within mammalian cells will expand our understanding of the structure/function relationships for functionalized nanoparticles.
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