Liebel will develop a phototransient microscope (PIROscope): an innovative biomedical imaging platform that will provide chemically resolved images of biological materials such as cells, bacteria or tissue. He hopes to visualize molecular details of breast cancer tissue at high resolution and the metabolic activity of bacteria following antibiotics treatment.
Routine diagnostics in hospitals often rely on dyes to stain and visualize key cellular building blocks. The PIROscope identifies these structures based on their vibrational or chemical fingerprint. This approach eliminates complex, costly and often error-prone sample preparation steps and further measures the mass of the individual components. This quantity is very difficult to access with conventional techniques, but it contains important information as the severity of a condition is often linked to the absolute amount, and not just the mere presence of a marker.
Method
PIRO is the combination of two lines of research: femtosecond spectroscopy and interferometric, phase-sensitive, imaging. The first uses very short pulses of light to record stop-motion images of molecules, essentially a very fast camera with an ultra-short flash for chemistry. The latter uses a property of light called "phase", basically a memory of the path the light traveled from its source, such as a laser or a lamp, to the camera: it can be used to reconstruct the weight of an object by shining light through it.
The PIROscope combines these two concepts: it uses short infrared pulses to heat the molecules in biological samples by a few degrees. It then captures an image of the light’s phase passing through the sample to infer the local temperature change. This measurement directly reveals the chemical composition of the sample. One of the most important aspects is that everything happens on very fast time scales: "We heat and measure before the sample cools down. Like this, we ensure that none of the crucial information is lost", says Liebel.
About the Starting Grant
The ERC uses the Starting Grants to support talented early-career scientists to carry out pioneering projects for a period of five years. A total of 408 early-stage researchers have been awarded ERC Starting Grants. More information can be found in ERC's press release.