NCCR Bio-Inspired Materials researchers have developed a groundbreaking imaging method. Based on the use of a single-photon camera, it can characterize thousands of molecules quickly and simultaneously.

This innovation, inspired by an imaging technique first developed more than 30 years ago, takes ultraprecise measurements of a molecule’s unique light-emission signature at the scale of a billionth of a second. At its heart is a high-tech single-photon avalanche diode (SPAD) camera, equipped with nearly one million tiny sensors capable of detecting photons with exquisite sensitivity. By analyzing how molecules emit light after being stimulated with laser pulses, scientists can rapidly identify and study individual molecules. This fluorescence lifetime imaging, which is slightly less accurate but far faster than existing methods, substantially cuts analysis time, enabling rapid analyses of large protein samples.

Led by NCCR PI Aleksandra Radenovic at Lausanne’s Federal Institute of Technology (EPFL), the development benefited from extensive teamwork among research groups and engineering specialists. The collaboration also included NCCR PI Guillermo Acuña’s group at the University of Fribourg, highlighting once again the benefits of the Center’s collaborative research approach.

The researchers have also adapted the method to measure the nanoscale distances between molecules using Förster resonance energy transfer (FRET), offering a powerful tool for studying dynamic biological phenomena. This approach hinges on the fact that the fluorescence lifetime of a “donor” molecule changes if an “acceptor” molecule is nearby.

Measuring the fluorescence lifetime of a pair of molecules provides information on the distance between them at a scale of just a few nanometers. The current approach can only be applied to small samples but could be expanded to allow for the rapid study of dynamic phenomena on thousands of molecules.

The new single-photon imaging method is not just faster, according to the researchers, it opens doors to large-scale studies of entire sets of biological molecules, such as genes, proteins, and metabolites, in a living system.

Original story: EPFL

Reference: Ronceray, N.; Bennani, S.; Mitsioni, M. F.; Siegel, N.; Marcaida, M. J.; Bruschini, C.; Charbon, E.; Roy, R.; Dal Peraro, M.; Acuna, G. P.; Radenovic, A. Wide-Field Fluorescence Lifetime Imaging of Single Molecules with a Gated Single-Photon Camera. Light Sci Appl 2025, 14 (1), 1–11. https://doi.org/10.1038/s41377-025-01901-2.