PPSM Laboratory: Innovating at the frontier of materials and light to meet the challenges of tomorrow

08/11/2024

The Supramolecular and Macromolecular Photophysics and Photochemistry Laboratory (PPSM) focuses its research on the study of molecules and materials that can be activated by photo-induced phenomena, electrons, ions or biological activity. This work is integrated into crucial fields such as the environment, health, information technology and heritage. These research activities in photochemistry, electrochemistry, nanomaterials and ancient materials are carried out by 44 researchers and doctoral students.

Molecules to detect and protect the environment

One of PPSM's priorities is the development of new fluorescent molecular probes for the detection of environmental pollutants. Fluorescent molecules capable of detecting toxic metal ions such as cesium or cadmium at very low concentrations, or pesticides (atrazine, glyphosate), have been or are currently being developed. These systems pave the way for promising applications in contaminated water monitoring, with unrivalled sensitivity, notably through devices integrated into microfluidic chips that enable the design of miniaturized sensors.

Towards innovative luminescent devices

The laboratory is also interested in applications related to luminescent devices. PPSM researchers are working on electrofluorochromic materials and molecules with specific emission properties for display, sensor and security technologies. For example, the misting of fluorophores synthesized in the laboratory for fingerprint detection represents a major breakthrough in forensic science. This process can be used directly in the field, without prior treatment, while increasing detection sensitivity.

A multidisciplinary approach to pioneering solutions

In collaboration with other disciplines such as the humanities and social sciences, PPSM is involved in a wide range of projects, including heritage restoration. The study of ancient materials using photoluminescence techniques provides a better understanding of ancient conservation practices for works of art and archaeological textiles, paving the way for more ecological restoration methods. This specialization reinforces the laboratory's interdisciplinary dimension by combining chemistry and cultural heritage.

Biological and biomedical applications

Another dimension of PPSM's research involves biology and medicine. Researchers have designed fluorescent probes for imaging. These molecules are used to monitor biological processes such as neuronal transmission or to detect disease, as well as to photo-deliver active ingredients. They are also exploring the synthesis of new molecules and materials capable of enhancing energy storage and conversion in biomedical contexts, with applications ranging from neurotransmitter detection to contrast agents for imaging.

Advances in fundamental knowledge

PPSM's research contributes significantly to the advancement of knowledge in key scientific fields such as photochemistry, fluorescence and molecular recognition, as well as the development of specific instrumentation coupling several techniques. By combining these fields with skills in organic synthesis and electrochemistry, the laboratory plays a fundamental role in the design of new molecules and materials, while studying their properties at different spatio-temporal scales thanks to these instrumentations, ranging from the detection of individual molecules to complex devices.

New lines of research

PPSM continues to explore intelligent materials capable of responding to mechanical, light or electrical stimuli. Researchers are currently working on photomechanical systems, where light can induce changes of shape in materials. This advance could pave the way for applications in optical devices or artificial muscles. In addition, research into the combination of plasmonic nanomaterials and redox and/or fluorescent molecules promises breakthroughs in ultra-sensitive detection, notably for biological and environmental sensors, and all-optical control of light conversion phenomena.

Highlights

One of PPSM's flagship achievements is the creation of fluorescent probes capable of detecting toxic compounds in a variety of media, with applications in environmental protection. At the same time, the unit has succeeded in designing photochromic (light-activated) and electrofluorochromic (electrically activated) systems, with applications in security, display and energy storage. These successes have strengthened international collaborations, notably with teams in Japan and the USA, paving the way for new high-performance devices.

Collaborations with companies

The PPSM (ENS Paris-Saclay, CNRS) collaborates with several companies to accelerate the application of its scientific discoveries. Key collaborations include

Crime Science Technology - In partnership with this forensic science company, PPSM has developed an innovative method for detecting latent fingerprints. This technology is based on the fogging of a fluorophore to rapidly reveal invisible fingerprints at crime scenes, saving time and increasing accuracy for law enforcement agencies.
Safran - As part of its research into photochromic materials for optical and energy applications, the laboratory is collaborating with Safran. This partnership has led to the development of “all-optical” neuromorphic materials, capable of modulating their color according to ambient light, an advantage for aeronautics and other industries requiring intelligent systems.
SATT Paris-Saclay - Thanks to the support of this technology transfer accelerator, PPSM has been able to develop detection devices for the agri-food industry, notably for detecting odorous compounds such as boar smell in pork.

Collaborations with research organizations

In addition to its industrial collaborations, PPSM works with several research organizations to further its discoveries and develop new scientific applications:

CEA Saclay - In collaboration with the CEA, PPSM is working on the development of chiral luminescent materials for use in innovative optoelectronic devices. This research focuses in particular on the creation of more efficient systems for energy storage and conversion technologies.
ESRF, Grenoble and Synchrotron SOLEIL - The PPSM is actively involved in research into ancient materials and works of art. Thanks to these large-scale facilities and an ongoing European contract, the laboratory has been able to deepen its studies into ancient textile and painting conservation practices, in conjunction with more environmentally-friendly restoration approaches.

International collaborations

The PPSM relies on strong international collaborations, notably with:

Kumamoto University, Aoyama Gakuin University, Nara Institute of Science and Technology, Japan - These collaborations focus on fluorescence amplification in photocommutable systems. Researchers have developed molecules capable of complete fluorescence quenching and restoration under irradiation, paving the way for super-resolved imaging technologies.
CNR Lecce, Italy - This collaboration involves the development of emissive molecular materials for optoelectronic applications.
University of Seville, Spain - This collaboration concerns the synthesis of photocommutable sugars and their use in cells for the treatment of certain diseases.

These academic and industrial partnerships, at both national and international level, reinforce PPSM's position as a major player in scientific and technological innovation in all fields where fluorescence can provide a solution to the challenges of energy detection, imaging, conversion or storage.