Lanthanide near infrared imaging in living cells with Yb^sup 3+^ nano metal organic frameworks

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 110; no. 43; p. 17199
• Main Authors: Foucault-Collet, Alexandra, Gogick, Kristy A, White, Kiley A, Villette, Sandrine, Pallier, Agnès, Collet, Guillaume, Kieda, Claudine, Li, Tao, Geib, Steven J, Rosi, Nathaniel L, Petoud, Stéphane
• Format: Journal Article
• Language: English
• Published: Washington National Academy of Sciences 22-10-2013
• Subjects: Chemical elements; Cytoplasm; Hydrocarbons; Infrared imaging systems; Metals; Microscopy; Molecular chemistry; Nanomaterials
• ISSN: 0027-8424; 1091-6490

We have created unique near-infrared (NIR)-emitting nanoscale metal-organic frameworks (nano-MOFs) incorporating a high density of Yb^sup 3+^ lanthanide cations and sensitizers derived from phenylene. We establish here that these nano-MOFs can be incorporated into living cells for NIR imaging. Specifically, we introduce bulk and nano-Yb-phenylenevinylenedicarboxylate-3 (nano-Yb-PVDC-3), a unique MOF based on a PVDC sensitizer-ligand and Yb^sup 3+^ NIR-emitting lanthanide cations. This material has been structurally characterized, its stability in various media has been assessed, and its luminescent properties have been studied. We demonstrate that it is stable in certain specific biological media, does not photobleach, and has an IC^sub 50^ of 100 μg/mL, which is sufficient to allow live cell imaging. Confocal microscopy and inductively coupled plasma measurements reveal that nano-Yb-PVDC-3 can be internalized by cells with a cytoplasmic localization. Despite its relatively low quantum yield, nano-Yb-PVDC-3 emits a sufficient number of photons per unit volume to serve as a NIR-emitting reporter for imaging living HeLa and NIH 3T3 cells. NIR microscopy allows for highly efficient discrimination between the nano-MOF emission signal and the cellular autofluorescence arising from biological material. This work represents a demonstration of the possibility of using NIR lanthanide emission for biological imaging applications in living cells with single-photon excitation. [PUBLICATION ABSTRACT]