A highly specific gold nanoprobe for live-cell single-molecule imaging

Cecile Leduc (1) , Satyabrata Si (1) , Jérémie Gautier (2) , Martinho Soto-Ribeiro (3) , B. Wehrle-Haller (3) , Alexis Gautreau (2) , Gregory Giannone (4) , Laurent Cognet (1) , Brahim Lounis (1)

1 lp2n-04,lp2n-12
2 LEBS - Laboratoire d'enzymologie et biochimie structurales
3 University of Geneva
4 IINS - Interdisciplinary Institute for Neuroscience [Bordeaux]

Single molecule tracking in live cells is the ultimate tool to study subcellular protein dynamics, but it is often limited by the probe size and photostability. Due to these issues, long-term tracking of proteins in confined and crowded environments, such as intracellular spaces, remains challenging. We have developed a novel optical probe consisting of 5-nm gold nanoparticles functionalized with a small fragment of camelid antibodies that recognize widely used GFPs with a very high affinity, which we call GFP-nanobodies. These small gold nanoparticles can be detected and tracked using photothermal imaging for arbitrarily long periods of time. Surface and intracellular GFP-proteins were effectively labeled even in very crowded environments such as adhesion sites and cytoskeletal structures both in vitro and in live cell cultures. These nanobody-coated gold nanoparticles are probes with unparalleled capabilities; small size, perfect photostability, high specificity, and versatility afforded by combination with the vast existing library of GFP-tagged proteins.

Domaines: Biophysique [physics.bio-ph]

Cecile Leduc, Satyabrata Si, Jérémie Gautier, Martinho Soto-Ribeiro, B. Wehrle-Haller, et al.. A highly specific gold nanoprobe for live-cell single-molecule imaging. Nano Letters, 2013, ⟨10.1021/nl304561g⟩. ⟨hal-00796925⟩