Jerome Wenger NanoBioPhotonics

Metal oxide nanoparticles play a pivotal role across many fields of nanoscience and nanotechnology, yet their detection remains challenging, requiring expensive SEM or TEM microscopies. Moreover, metal oxide nanoparticles generally form complex nanoaggregates of different sizes and morphologies, requiring experiments to be performed at the level of a single nanoaggregate to yield meaningful information.

In our recent article published in Particle & Particle Systems Characterization, we detail a novel application of ultraviolet (UV) microscopy for detecting metal oxide nanoparticles with high sensitivity and versatility. By leveraging the strong absorption of metal oxides in the UV spectral range, we demonstrate robust detection capabilities, validated through correlative electron microscopy and numerical simulations. Our results provide critical information characterizing the material and morphology parameters determining the UV response of metal oxide nanoaggregates

This work offers significant advancements for nanoparticle analysis, with potential applications spanning across material science, biotechnology, and environmental monitoring.

We are delighted to congratulate Malavika Kayyil Veedu on the successful defense of her PhD thesis, “Exploring and improving fluorescence correlation spectroscopy (FCS) sensitivity from nanoprobe to label-free proteins for biosensing and nanopore applications,” defended on January 29, 2026, at the Institut Fresnel in Marseille.

Malavika’s work explored innovative strategies to push the limits of fluorescence correlation spectroscopy (FCS) and its time-resolved variant (FLCS). By tackling key challenges such as background noise, spectral overlap, and photobleaching, she developed approaches that improve sensitivity and enable the study of weakly fluorescent nanoparticles or label-free proteins. Her research opens exciting perspectives for biosensing and nanopore-based optical detection.

The thesis jury included:

• Dr. Thomas Pons (LPEM, INSERM Paris) – Reviewer
• Dr. Karen Perronet (LuMIn, CNRS Gif-sur-Yvette) – Reviewer
• Dr. Serge Monneret (Institut Fresnel, CNRS Marseille) – Examiner
• Prof. Antoine Delon (LIPhy, Université Grenoble Alpes) – Jury President
• Dr. Jérôme Wenger (Institut Fresnel, CNRS Marseille) – Thesis Supervisor

We warmly congratulate Dr. Kayyil Veedu for her excellent work, dedication and team spirit throughout her PhD journey. We wish her all the best for her future endeavors!

Our recent publication in Small presents a new scalable way to fabricate zero-mode waveguides (ZMWs) which are metallic nanoapertures confining light into volumes 1000x smaller than the diffraction limit. These nanostructures enable single-molecule fluorescence detection at biologically relevant micromolar concentrations, something traditional microscopes cannot achieve.

By combining sol-gel nanoimprint lithography with hydrofluoric acid vapor etching, we developed a cost-effective, high-throughput process to produce high-performance ZMW arrays without expensive nanofabrication tools. Experiments with single fluorescent molecules demonstrated the effectivity and performance of our ZMWS for single molecule fluroescence detection, showing up to eightfold brightness enhancement and sub-millisecond temporal resolution across the visible spectrum.

This work opens the door to affordable, large-scale nanostructures devices, making nanophotonics techniques more accessible for applications in biophysics, biosensing, and advanced fluorescence microscopy.

Congratulations Hamza! Accessible freely through gold open access.

Two positions are open in our group for Master 2 internship in spring / first semester 2026 combined with a 3-years PhD fellowship starting in Fall 2026:

- Optical sequencing of digital polymers for molecular data storage: develop a groundbreaking optical sequencing platform that decodes fluorescently encoded polymers, paving the way for fast, high-throughput molecular data storage.

- Nanoplastics Detection Exploiting UV Autofluorescence for Enhanced Sensitivity: pioneer a groundbreaking UV autofluorescence approach that reveals and identifies nanoplastics as small as 30 nm—unlocking new frontiers in the fight against invisible plastic pollution.

Applications by email to Jerome Wenger with a CV, a letter of interest, academic transcripts and the name of a past supervisor serving as reference.

The optical detection of nanoparticles plays a pivotal role across many fields of nanoscience and nanotechnology, yet the weak optical response of single nanoparticles in the visible spectral range often challenges their detection. Dielectric materials such as polystyrene nanoparticles are especially difficult to detect as they remain nearly transparent across the visible domain.

In our recent Optics Express publication, we present a novel application of ultraviolet microscopy for detecting single nanoparticles with high sensitivity and versatility. By leveraging the strong absorption of both metallic and dielectric nanoparticles in the UV spectral range, we demonstrate robust detection capabilities, validated through correlative electron microscopy and Mie theory simulations. This work offers significant advancements for nanoparticle analysis, with potential applications spanning across material science, biotechnology, and environmental monitoring.