Jerome Wenger NanoBioPhotonics

Plasmonic optical nanoantennas have revolutionized the control of light-matter interactions at the nanoscale. However, until now, their exploration has been largely restricted to the visible and near-infrared regions, overlooking the immense potential of the ultraviolet range, which boasts the strongest absorption for most molecules. In a recent ACS Nano article, entitled “Ultraviolet Resonant Nanogap Antennas with Rhodium Nanocube Dimers for Enhancing Protein Intrinsic Autofluorescence” we overcome the materials and technical limitations of UV nanophotonics and report the first experimental realization of UV resonant nanogap antennas.

Our design relies on the directed self-assembly of rhodium nanocubes into dimer nanogap antenna. We pioneer the use of rhodium as a robust alternative to aluminum, offering enhanced stability in aqueous environments and ensuring reliable UV performance. Our results demonstrate the pivotal role played by the nanogap and stand in excellent agreement with numerical simulations.

We apply the UV nanoantennas to enhance the UV autofluorescence from single label-free proteins, and achieve unprecedented enhancement factors up to 120 fold together with zeptoliter detection volumes. By enhancing the protein autofluorescence signal by up to two orders of magnitude, our results unlock powerful perspectives for local measurements of concentration, mobility, brightness, and stoichiometry of label-free proteins, circumventing the need for external fluorescent labels.

This work broadens the scope of applicability for plasmonic nanoantennas into the deep UV range, unlocking novel avenues to take maximum advantage of the strong molecular response in the UV regime.

Open access on ACS Nano website. Also available through ArXiv 2309.04152. Enjoy!

Two positions are currently open with funding from China Scholarship Council CSC and Groupe Ecoles Centrales GEC-CSC:

- One for a PhD: "Optically-controlled thermal nanotweezers to manipulate single nano-objects"

- One for a postdoc: "Deep UV optical nanoantennas to enhance the ultraviolet autofluorescence of single proteins"

Find them on the https://gec-csc.fr/ website with application form, section Natural & Life sciences: Physics & Astronomy. Application deadline January 10 2024!

We're thrilled to introduce the latest addition to our research family, Hamza Khelidj! Hamza joins our team with a passion for nanoscience and a keen interest in the development of zero-mode waveguide nanoapertures.

Hamza's expertise in nanofabrication promises to be a game-changer in our ongoing quest for cutting-edge research and innovation. We're excited to see the incredible contributions that Hamza will make to our team and to the field of nanoscience as a whole. Together, we're destined to create a future filled with breakthroughs and discoveries.

We are pleased to announce the arrival of  Xinyu Fang, who will be joining us as a PhD student for the next four years with CSC-Centrale funding. She will be working with us on a research project on ultraviolet autofluorescence imaging.

We would like to extend a warm welcome to Xinyu and encourage you to reach out to her with any questions or for collaboration opportunities.

In a recent breakthrough, the journal Communication Physics published a study titled "Experimental evidence of Förster energy transfer enhancement in the near field through engineered metamaterial surface waves." This research delves into the intriguing interplay between surface plasmons and Förster resonant energy transfer (FRET), shedding light on a relatively unexplored phenomenon.

Through microwave experiments, the study reveals that by exciting surface waves on a specialized metasurface, FRET can be greatly enhanced in the near-field region. In essence, this means that energy transfer between two emitters, when separated by distances smaller than the wavelength of light, can be efficiently controlled.

The key to this breakthrough lies in the metasurface—a carefully designed interface that can regulate dipole-dipole energy transfer. By harnessing metamaterials, researchers crafted this metasurface to act as a conduit for precise FRET manipulation.

The implications of this discovery are vast and hold the potential to impact various fields from advanced lighting to photovoltaics.