With her project SEEAFM, Estelle Lebègue, a lecturer-researcher at the CEISAM laboratory, has been selected as a laureate of the Emergence@INC 2026 call for projects. Through this scheme, CNRS Chemistry supports researchers—research fellows or associate professors recruited within the past 5 to 10 years—by funding innovative projects and encouraging scientific risk-taking.
The SEEAFM project aims to develop an experimental platform combining atomic force microscopy (AFM) and electrochemistry in order to study, at the level of individual entities, very small biological structures such as bacteria or liposomes. The objective is to understand the mechanisms of electron transfer occurring during their collision with the surface of a polarized ultramicroelectrode. SEEAFM fits within the framework of electrochemical exchanges associated with individual collisions, or nano-impacts, the analysis of which enables the identification and characterization of a wide variety of entities at ultramicroelectrodes. Unlike ensemble measurements, this approach offers the major advantage of accessing electrochemical properties at the scale of a single object. However, it also raises significant challenges, notably the analysis of charge transfer occurring over timescales shorter than half a second, particularly for soft and/or living objects.
Coupling nano-impact electrochemistry with AFM represents a major technical challenge in itself, as it involves probing mobile entities on the order of a few hundred nanometers on a polarized surface only a few micrometers in diameter. At CEISAM, progress has already made it possible to image bacteria and liposomes on disk ultramicroelectrodes, although direct correlation of these images with prior electrochemical measurements has not yet been achieved. To address this challenge, the project will rely on a collaboration with a Paris-based team with expertise in AFM–SECM applied to biological entities.
The expected outcomes of SEEAFM will make it possible to evaluate the electrochemical behavior of electroactive bacteria and redox-active liposomes at the level of individual entities, thereby pushing back the current limits of charge-transfer analysis in these complex systems. The project will also contribute to a better fundamental understanding of lipid membrane permeability and of the mechanisms by which these membranes open upon contact with a polarized electrode, particularly in the context of electroporation processes. Ultimately, these advances could pave the way for biotechnological applications in the fields of energy (biofuel cells) and health (biosensors).
