Articles récents

Fast interaction dynamics of G-quadruplex and RGG-rich peptides unveiled in zero-mode waveguides

3 Janvier 2022 , Rédigé par JW

G-quadruplex structures of DNA are promising target sites for anticancer therapy. However, the interaction of G-quadruplex with proteins remains poorly understood, notably the association and dissociation kinetics.

In a recent Nucleic Acid Research publication entitled “Fast interaction dynamics of G-quadruplex and RGG-rich peptides unveiled in zero-mode waveguides”, we use 120nm nanoapertures to measure the interaction dynamics between G-quadruplexes and peptides at micromolar concentration.

Significance:

- The association and dissociation kinetics of the interaction are fully characterized for the first time and discussed in perspective of the nature and specificity of this interaction.

- Our approach using ZMW combined with FCCS-FRET opens up a new technique to investigate the previously unexplored interactions of DNA structures with a library of peptides at µM concentration. This is important to develop the antiviral and anticancer drug therapy applications involving G-quadruplexes.

Open access direct from the publisher or from our academic repository HAL.

 

Open position: contractual researcher plasmonic optical nanotweezers

12 Novembre 2021 , Rédigé par JW

We are opening a position for postdoctoral fellowship: experimental nanophotonics and plasmonic nano-optical tweezers.

Read the details and apply through the CNRS institutional website: https://bit.ly/3HiobDC

Position filled and no longer available. Contact Jerome Wenger for enquiries.

 

Single Photon Source from a Nanoantenna-Trapped Single Quantum Dot

27 Septembre 2021 , Rédigé par JW

Plasmonics can be used to enhance the emission properties of single quantum nano-objects and use them as bright ultrafast single photon sources. However, plasmonic trapping single quantum objects has remained highly challenging so far.

In a recent Nano Letters publication, we introduce a dedicated plasmonic nanoantenna design to trap single colloidal quantum dots and enhance their single photon emission. The nano-optical trapping automatically locates the quantum emitter at the nanoantenna hotspot where the emission enhancement is maximum.

Novelty and Impact:

- Enhanced single photon brightness is demonstrated from a trapped single quantum dot, together with strongly reduced blinking and accelerated lifetime. This provides a significant advance over previous reports lacking a clear demonstration of antibunching.

- Our novel nanoantenna design achieves the highest trap stiffness reported so far for individual quantum dots, allowing to reduce the trapping intensity and mitigate the thermal effects.

Preprint also freely available on ArXiv 2108.06508

 

European Researchers Night 2021

16 Septembre 2021 , Rédigé par JW

Back into direct physical format, Jerome will participate to the next "Nuit Européenne des Chercheurs" at Aix en Provence on Sept. 24th. More details and program here.

 

Purcell radiative rate enhancement of label-free proteins with ultraviolet aluminum plasmonics

26 Août 2021 , Rédigé par JW

Ultraviolet plasmonics has attracted recently a growing attention owing to the possibility to take advantage of increased light-matter interaction in the UV range. However, the core question of demonstrating the capacity of UV plasmonic structures to enhance the radiative emission rate of proteins has remained unproven yet.

In a recent article published in J . Phys D Appl. Phys, we report the first complete demonstration of the Purcell radiative rate enhancement for label-free proteins in plasmonic aluminum nanoapertures. Regardless of the complexity of protein structure and its low intrinsic emission quantum yield, we can clearly show that the aluminum plasmonic nanoapertures can significantly enhance the spontaneous UV emission rate of proteins. Our results show that concepts developed for single quantum sources in the visible can still be applied on complex proteins containing thousands of aminoacids.

Open access paper also freely available on arXiv 2107.06357

 

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