QuantERA project EXTRASENS: Color centers in diamond nanoneedles for intra- and extra-cellular quantum sensing

Fundamental life science and practical medicine need tools to probe the physical characteristics of the media inside the living cells. Each cell is an individual organism, and its health can be controlled via measuring the electromagnetic field, temperature, and pH values. Notably, it is important to know these values in different parts of the cell – the nucleus, the membrane, mitochondria, etc – to localize the sign of pathology within the cell with the best possible precision. Recent advances in solid state physics have resulted in discovery of objects that can operate as atomic size pH-meter, magnetometer or thermometer. These are so-called nitrogen-vacancy (NV) and silicon-vacancy (SiV) color centers in diamond single crystals. Like many other quantum systems these vacancy color centers (VCCs) absorb light quanta of specific energies and can radiate light quanta with smaller energies back. The difference in energy corresponds to a certain quantum transition within such systems. This is called photoluminescence. A peculiarity of the diamond NV and SiV centers is that the intensity, and frequency of the photoluminescence is very sensitive to the mentioned characteristics of the medium around the vacancy center. EXTRASENS project will employ these unique properties to create a novel multimodal quantum biosensor complemented with super resolution bioimaging functionality. The VCCs will be incorporated into single crystal nanoneedles (DNNs) functionalized the way to be delivered to particular cells or even cell parts. This will allow for the measurements of targeted physical values with a special resolution less than 20 nm. EXTRASENS technology and its integral parts, will provide direct benefits for European society and citizens enabling in the middle-to-long run new strategies and standards for disease diagnosis, prognosis, and (crucially) prevention, and as a result improving wellbeing. Consortium will contribute to EU strategic autonomy in quantum technology materials and applications, being the added value of transnational EU cooperation in the quantum domain.