Accueil › IMPORT ne pas tenir compte de cet espace

Nanoantenna enhanced fluorescence

Antennas in nanobiophotonics

Nanophotonics offer new opportunities to further improve single molecule optical detection beyond the diffraction limit. The main goal is to tailor the electromagnetic environment by the use of an optical antenna to concentrate the light on a tiny spot and simultaneously enhance the molecular emission. Single molecule spectroscopy techniques, FRET and FCS can greatly benefit from photonic nanoantennas to enter a new dimension of higher sensitivities at molecular concentrations reaching physiological conditions.

Photonic engineering of fluorescent dyes

In a collaboration between the Fresnel Institute and ICFO-the Institute for Photonic Sciences, we develop a novel “antenna-in-box” platform for single molecule fluorescence detection with unprecedented resolutions and sensitivity. The innovative approach combines a plasmonic gap antenna for ultra-high fluorescence enhancement with a metal nanoaperture for optimized background-free operation. It allows for 1100-fold fluorescence brightness enhancement together with detection volumes down to 58 zeptoliters (1 zL = 1e-21L), realizing a gain of four orders of magnitude as compared to classical microscopes. The antenna-in-box offers a highly efficient platform for nanoscale biochemical assays with single molecule sensitivity at physiological conditions.

This research is done in close collaboration with the groups of Niek Van Hulst and Maria Garcia-Parajo at ICFO, and is part of the NANO-VISTA project, funded by the European Commission’s 7th research Framework programme.

Photonic engineering of fluorescent dyes

The development of bright water-soluble luminescent probes is a ubiquitous problem in imaging and sensing applications. Designing fluorescent dyes typically relies on a molecular engineering approach in which photophysical properties are tuned by chemical modifications.

We present a novel way of engineering the luminescence by changing the photonic environment of a chromophore while maintaining its solubility. We produce purified suspensions of gold nanoparticle dimers linked by a single DNA double strand exhibiting one a single dye molecule. Tuning the electromagnetic field enables unprecedented photophysical properties, such as decay rates and excitation cross-sections enhanced by more than one order of magnitude compared to an optimized, commercial chromophore.

This research is done in close collaboration with the group of Sebastien Bidault at Institut Langevin.

Optical antennas to tune colloidal quantum dots luminescence

We explore the interaction between colloidal quantum dots (QD) emitters and plasmonic antennas via an in-depth analysis of the QD multiply excited states. The influence of the antenna on the luminescence, excitation intensity and emission quantum yield are quantified separately. This is made only possible by combining two technological breakthroughs : (i) the custom-synthesis of colloidal QD with controlled multiply excited states, and (ii) the deterministic QD-antenna coupling via double step e-beam lithography.

A remarkable feature of this approach is that excitation enhancement can still be investigated even in the presence of strong quenching losses affecting the emission. This provides new routes to experimentally investigate the physics of optical antennas, and optimize the excitation and emission processes independently.

This research is done in close collaboration with the groups of Dan Oron at Weizmann Institute of Science and Romain Quidant at ICFO, and is conducted in the scope of the NaBi associated European laboratory.

Selected publications

  • D. Punj, P. Ghenuche, S. B. Moparthi, J. de Torres, V. Grigoriev, H. Rigneault, J. Wenger, Plasmonic antennas and zero-mode waveguides to enhance single molecule fluorescence detection and fluorescence correlation spectroscopy toward physiological concentrations, WIREs Nanomed Nanobiotechnol 6, 268 (2014).
  • D. Punj, M. Mivelle, S. B. Moparthi, T. van Zanten, H. Rigneault, N. F. van Hulst, M. F. Garcia-Parajo, J. Wenger, A plasmonic ‘antenna-in-box’ platform for enhanced single-molecule analysis at micromolar concentrations, Nature Nanotech. 8, 512-516 (2013). pdf reprint
  • M. P. Busson, B. Rolly, B. Stout, N. Bonod, J. Wenger, S. Bidault, Photonic engineering of hybrid metal-organic chromophores, Angew. Chem. Int. Ed. 51, 11083-11087 (2012)
  • E. Bermúdez Ureña, M. P. Kreuzer, S. Itzhakov, H. Rigneault, R. Quidant, D. Oron, J. Wenger, Excitation enhancement of a quantum dot coupled to a plasmonic antenna, Adv. Mater. 24, OP314-OP-320 (2012).

The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) / ERC Grant agreements 278242 (ExtendFRET).