Jerome Wenger NanoBioPhotonics

Our article entitled “Breaking the low concentration barrier of single-molecule fluorescence quantitation to the sub-picomolar range” has recently been published in Small Methods.

Until now, the concentration range for effective single-molecule fluorescence detection was largely restricted to the concentrations above 50 pM, overlooking the immense potential of the single-molecule fluorescence for biosensing applications at sub-picomolar sensitivity.

In our work, we present a simple and effective modification to a confocal microscope setup that pushes the detection limit of fluorescence lifetime correlation spectroscopy (FLCS) down to 0.1 pM, overcoming the so-called low concentration barrier without the need for complex instrumentation or preconcentration techniques.

Main elements of significance:

• Adding a diaphragm on the laser excitation beam achieves a large detection volume together with a high fluorescence brightness per molecule. This is the key to push the sensitivity towards sub-picomolar concentrations.
• For the first time, we clearly discuss the physical parameters setting the lower the limit of quantification in FLCS and we introduce a universal figure of merit allowing to compare between experimental configurations.
• We demonstrate the effectiveness of our approach by monitoring the interaction dynamics of biotin-streptavidin binding, a highly relevant biochemical system yet challenging to measure on conventional systems due to its exceptionally high affinity.

These results open new avenues for applying single-molecule fluorescence detection to biosensing at sub-picomolar concentrations, with significant implications for biological and medical diagnostics.

Open access at Small Methods and available on the repository HAL 05043006.

We are glad to announce that Jerome Wenger has been elected to the rank of Fellow of Optica (formerly OSA) in recognition of his contributions to the field of optics and photonics. The citation reads: “For pioneering contributions to nanophotonics and optical nanoantennas to enhance single molecule fluorescence.”

As ChatGPT writes it: "This prestigious honor reflects Jerome’s impactful research at the intersection of nanophotonics and single-molecule spectroscopy. His work on designing and using optical nanoantennas to control light at the nanoscale has opened new frontiers for enhancing fluorescence signals, enabling more sensitive and precise measurements in biological and chemical systems.

Being named a Fellow is a significant milestone, reserved for individuals who have made distinguished contributions to optics and photonics. Optica Fellows represent the top 10% of the society’s membership, selected through a rigorous peer review process. Congratulations, Jerome, on this well-deserved recognition!"

Thanks ChatGPT that is so heart-warming 😊

Our recent work, “Watching lanthanide nanoparticles one at a time: characterization of their photoluminescence dynamics at the single nanoparticle level,” has been accepted for publication in Nanoscale.  

Lanthanide nanoparticles (LnNPs) are gaining attention for their potential in biosensing and bioimaging, but until now, their photoluminescence behavior at the single nanoparticle level remained poorly understood. In this study, we go beyond traditional ensemble measurements by using fluorescence correlation spectroscopy (FCS) and photoluminescence burst analysis to explore the emission dynamics of Sm and Eu-based LnNPs with single-particle sensitivity and microsecond resolution. Our results reveal key insights into the brightness, emission stability, and the number of emitting centers within individual nanoparticles.

Most importantly, we demonstrate the ability to detect and analyze single LnNPs—an exciting step forward for high-precision sensing and imaging applications. This work helps bridge the gap between ensemble-averaged spectroscopy and single-molecule techniques, opening new possibilities for the use of LnNPs in next-generation bioanalytical tools.

Read the preprint on ArXiv 2412.07443

Our account @Photonicsnano was essentially on hold over the last year, waiting to see how X/twitter evolves. Thanks Elon for making things evidently clear by using a sign instantly recognisable by (almost) everybody on this planet.

We don't recognize ourselves in the values displayed by X/twitter and its president. Our account has been definitely closed. At least I can think of my grandfather without feeling ashamed about myself.

We are pleased to announce the arrival of  Jinchao Chen within our team for his M2 master thesis. Jinchao will be on a research project on thermoplasmonics and nano-optical trapping.

We would like to extend a warm welcome to Jinchao and are looking forward to stimulating discussions!