Periodic Reporting for period 1 - FaBriCATion (Fast Brillouin microscopy for phase transition)
Reporting period: 2023-10-01 to 2025-09-30
The primary objective was to develop an advanced Brillouin microscopy platform capable of non-invasive, high-speed, and high-resolution mechanical mapping of living cells. The project's pathway to impact was designed to bridge the gap between optical engineering and clinical diagnosis. By providing a tool that can quantify the "stiffness" of protein condensates, the project aimed to provide pharmaceutical researchers with a new metric for drug efficacy. In the strategic context of the European Research Area (ERA) , this project sought to reinforce Europe's leadership in biophotonics by creating a robust infrastructure that could be shared across multidisciplinary research groups.
Deep Investigation of Coherent Detection: We conducted a systematic study of heterodyne Brillouin detection. Our research identified fundamental Signal-to-Noise Ratio (SNR) limits at bio-safe power levels, providing the community with a definitive framework for the feasibility of high-speed coherent sensing in living cells.
Engineering of an Ultra-Stable EOM Platform: To address the industry-wide problem of spectral drift, we successfully integrated an Electro-Optic Modulator (EOM) into a 780nm Brillouin microscope. We developed a custom closed-loop control system that achieved record-breaking instrumental stability (>50 hours), enabling long-term observations that were previously impossible.
Biological Discovery (Tau Protein): Using this stabilized platform, we performed mechanical mapping of Tau protein phase transitions in living SK-N-BE neuroblastoma cells. We successfully documented the mechanical hardening of protein droplets over time, correlating these shifts with molecular mobility data obtained through integrated FRAP (Fluorescence Recovery After Photobleaching) .
Infrastructure Sharing: The system's robustness allowed us to provide transnational access to three international research groups, validating the technology's utility for diverse biological models beyond the original scope.
Beyond State-of-the-Art Stability: Before this project, VIPA-based Brillouin spectrometers typically required recalibration every few hours. Our EOM-stabilized architecture represents a paradigm shift, offering a "set-and-forget" capability that is essential for high-throughput screening and long-term live-cell imaging.
Fundamental SNR Insights: Our deep study into heterodyne detection corrected common misconceptions in the field regarding the speed-power trade-off, setting a new standard for how researchers should design coherent Brillouin systems.
Potential Impacts and Future Uptake:
Clinical Diagnostics: The ability to map mechanical shifts in proteins opens a pathway for early-stage biomarker detection in neurodegenerative research.
Market Readiness: Reaching TRL 4/5 , the EOM-stabilized setup is a prime candidate for commercialization or integration into existing commercial confocal microscopes.
Future Needs: To ensure further success, the next steps include a larger-scale internationalization of the protocol and the development of standardized "mechanical phantoms" for cross-laboratory calibration.
The project has not only delivered a superior imaging tool but has also established a FAIR-compliant data repository and open-source code library, ensuring the long-term reproducibility and scientific uptake of these innovations within the global biophysics community.