Chemistry meets quantum sensing: towards atomic architectures tailored for diamond probes
Quantum sensing is a recent, dynamically expanding field affecting many scientific and industrial disciplines, including chemistry, biochemistry, biology and medicine. I have been advancing this field by developing quantum physical principles for the detection of Nitrogen‑Vacancy (NV) spin states in diamond. In my recent collaboration with the hosting supervisor, we have demonstrated that nanodiamond particles (NDs) can act as an optical probe for redox reactions reaching unprecedented sensitivity of 10 external spins. ND probes have enormous potential for instance for intracellular localized detection, but the sensitivity is limited by short NV coherence times due to subsurface defects and unsaturated bonds. Moreover, the sensor specificity and colloidal stability in the biological liquids need to be addressed. I aim to tackle these drawbacks by developing a radically novel chemical approach to remove the unpaired electrons and by engineering ultrathin polymer coatings and linking strategies. To reach the project's complex goals, a highly interdisciplinary approach is proposed. My plan is to 1) annihilate the dangling bonds and subsurface defects by controlled surface removal using radical etching in the gas phase, 2) develop colloidally stable ND probes using ultrathin polymer coating, 3) use NV spin properties to optically detect paramagnetic ions and nucleic acids in biologically relevant conditions with unprecedented sensitivity. The proposed fellowship will allow me to look at the problematics of quantum sensors from the chemical point of view, complementing my expertise in physics. Furthermore, acquiring chemical skills by working in a leading ND surface chemistry group, will improve my prospects to become a leader in the topic of quantum biological sensing, which I want to pursue further in my home country. At the same time, I would like to bring to the host group my expertise in quantum sensing methodology that will be used in the project and beyond it.