Results' overview:
-Novel control schemes for enhanced sensitivity and polarization transfer, with rate improved by over a factor of 2.
-Demonstration of NV magnetic sensing with compressed sensing, achieving improved bandwidth of over a factor of 4 for similar sensitivity.
-Study of multiple spin baths - characterization of radicals through noise on shallow NVs, demonstrating a sensitivity of ~10 nMol/Hz^½ with sub-micron resolution.
-AZE-related sensitivity enhancements up to ≥500-fold reductions in the effective acquisition times for NMR experiments involving RNA imino protons, like those forming the genome of the SARS-CoV-2 viruses.
-Temperature sensing (with possible application in biological samples) based on ODMR measurement (sensitivity 5 mK/Hz^½) in bulk diamond.
-ODMR sensing protocols with NV centres showing 40 nT/Hz^1/2 magnetic sensitivity in continuous excitation (70 nT/Hz^½ in biocompatible conditions).
-A complex molecular environment (as murine brain) was explored using both in and ex vivo at high (14.1 15.2T) fields, using both conventional 2D NMR and our new AZE technique. In conjunction, these high field experiments have revealed ca. 10 and 29 metabolites in in- and ex-vivo, respectively, and lead to the assignment of 137 cross-peaks in total.
-Neuronal temperature variation (1K) at single-cell level correlated to modified network firing pattern detected via nanodiamond sensor based on ODMR.
-Theoretical and experimental demonstration of NV-spin coherence time enhancement by 10^3 due to nuclear spin bath noise filtering via AZE measurements.
-Enhanced coupling and polarization transfer between NV and the surrounding nuclear spin bath, through tuning the magnetic field through the level anticrossing, leading to longer coherence times (T2*, by up to almost a factor of 2).
-Enhanced ODMR magnetic sensing via both compressed sensing and machine learning schemes - achieve nearly order-of-magnitude improvement in the sensitivity-bandwidth product.
-Advanced implementations of noise sensing to singlet-triplet transitions in retinal excitation dynamics and to noise in magnetic excitations.
-AZE was used to optimize heteronuclear polarization transfer in the presence of fast solvent chemical exchanges, via J-based cross polarization (CP) strategies.
-In the area of biomolecule/pharmaceutical NMR, it was realized that the repolarization effects used so far on the basis of water exchanges, could also be leveraged in the presence of paramagnetic centers and/or when targeting low-abundance species like 13C in organic molecules.
-About x200 enhancement in SNR per sqrt unit time for certain 2D NMR experiments on nucleus acids. About x50 for certain 2D protein experiments. Enabling 17O and 14N MRI based on water detection.
-Characterization of nanodiamond ODMR temperature sensors to be used in Ramos’ cells after internalization with endocytosis, via a home-built scanning confocal microscope with capabilities of delivering microwave (MW) pulses to a diamond sample.
-In ND-based thermometry, by exploiting our ODMR technique in the weak orthogonal regime we improved the coherence time to T_2^*=2 µs, much longer than the standard high field states (T_2^*=0.88 µs). This implies an improvement in the temperature sensitivity of a factor \sqrt{2}.
-ML algorithms allowed us to get a x3 reduction in the number of required measurements for noise spectroscopy experiments via a single NV center in diamond (at room temperature).
-In NV-based magnetic sensing, our ML approach error scales better than the traditional raster scan, with an error of about 1 MHz with just 10 percent of the data points.
-Combining our advanced decoupling sequences with the pulsePol sequence for polarization transfer improves achievable target spin polarization by approx. x10.
-We have demonstrated robust noise characterization in the presence of coherent errors, with significantly improved robustness compared to standard techniques (in this case Ramsey interferometry). In this context, we demonstrated up to x2 better accuracy in the extracted T2*.
Their Exploitation and Dissemination are shown in www.pathos-fetopen.eu.
