Weil directs the Synthesis of Macromolecules department at the MPI for Polymer Research in Mainz (co-located with JGU, with which the department collaborates closely). The quantum-sensing core of her programme is nanodiamond: in 2026 her group published a bottom-up route that converts molecularly defined nanographenes into ultrasmall, size-uniform nanodiamonds under HPHT, incorporating SiV and GeV colour centres during synthesis rather than by post-hoc implantation -- addressing the long-standing problem that milled detonation nanodiamonds have poor size control and damaged surfaces. Alongside this sits a mature nanodiamond biosensing line: surface bioconjugation and nanogel encapsulation, T1 relaxometry for free-radical detection in single mitochondria and in cells, nanoscale thermometry and photothermal theranostics. Relative to the established NV-ensemble quantum-sensing playbook (DEER, nanoscale NMR, T1 relaxometry at pT/sqrt(Hz) ensemble sensitivity), this group is attacking the material bottleneck directly -- if you want NV/SiV ensembles with controlled size, surface and coherence for in-cell sensing, this is the synthesis end of that pipeline, and it feeds spin-readout collaborators at Ulm (Jelezko/Kubanek).