Jerome Wenger NanoBioPhotonics

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!

Gold nanoclusters (AuNCs) have garnered significant attention for their unique photoluminescent properties, holding large promise across a spectrum of applications. However, our understanding of their rapid photodynamics has remained elusive due to limitations posed by ensemble-averaged spectroscopy techniques.

To address this knowledge gap, we use fluorescence correlation spectroscopy (FCS) to delve into the photoluminescence dynamics of colloidal Au₁₈(SG)₁₄ nanoclusters. We address questions surrounding blinking behavior, brightness per nanocluster, and the influence of excitation power and ligands in a recent Nanoscale Advances publication. Notably, our findings reveal the distinctive quantum nature of the photoluminescence process, establishing each AuNC as an individual quantum source with a single emitting center.

In a second study published in BBA General Subjects, we combine water-soluble Au₁₈(SG)₁₄ gold nanoclusters with two organic fluorescent dyes, Alexa Fluor 647 and CF640R, presenting a ternary mixture of fluorescent emitters with nearly identical emission spectra. This work extends the capabilities of fluorescence lifetime correlation spectroscopy (FLCS) for the first time to a ternary mixture, surpassing traditional multiplexing limitations associated with distinct fluorescent dyes across the visible spectrum. Additionally, we demonstrate the suitability of gold nanoclusters for FLCS multiplexing applications, highlighting their microsecond lifetime and stable emission characteristics as valuable additions to the FLCS probe repertoire.
Our research contributes to the understanding of AuNC photodynamics, fostering the development of AuNCs in biosensing and imaging applications where single emitter resolution matters.

Both papers published open access. Open science matters.

Jerome will be co-chairman of the fourth edition of The Single-Molecule Sensors and NanoSystems International Conference which will be held in the historical center of Paris on October 28-30, 2024 at Chimie Paristech (11 rue Pierre et Marie Curie, 75005 Paris, France). Check the conference website here.

This conference brings together the leaders to discuss the most recent and exciting developments in the field of single molecules and nanosystems, covering detection and light-matter interactions from the molecular to the mesoscales.

The programme for S3IC2024 is building up fast, confirmed plenary speakers for 2024 are: Stefan Hell, Thomas Ebbesen, Philipp Tinnefeld, Philipp Kukura, Fedor Jelezko, Ronald Walsworth, Reuven Gordon, Laura Na Liu and Jeremy Baumberg. We also proudly have a very solid list of confirmed invited speakers, more on the conference website.

Important deadlines:

Early bird Submission - April 26, 2024
Early bird Registration - May 24, 2024
Submission -  July 5, 2024
Notification to authors - July 17, 2024
Registration - September 20, 2024
Conference - October 28-30, 2024