With support from the Chemical Measurement and Imaging Program, Professors Carlos A. Meriles (City College of New York) and Jeffrey A. Reimer (University of California at Berkeley), in collaboration with Delaware Diamond Knives, are working to enhance the sensitivity of nuclear magnetic resonance (NMR), an important chemical analysis tool used for wide-ranging applications that include determination of protein structure and folding dynamics; medical imaging (MRI); and probing porous rocks in search of oil. For all such applications, the limited sensitivity of NMR imposes restrictions on the minimum amount of sample that can be detected, and can result in long measurement times and limited access to expensive instrumentation. The Meriles/Reimer team is studying and utilizing interactions between light and engineered diamond crystals to enhance the sensitivity of NMR by several orders of magnitude under ambient conditions. Their multi-pronged approach - combining both fundamental and applied science - is enabling a wider range of applications and development of new contrast agents for multi-modal in-vivo imaging. This multi-institutional project is providing training opportunities targeting a diverse STEM workforce, including a number of educational opportunities at the undergraduate and high-school levels.
The Meriles and Reimer groups are pursuing a novel route to generating augmented nuclear spin polarization by leveraging the singular properties of nitrogen-vacancy (NV) centers, a paramagnetic defect in diamond that can be completely polarized via optical excitation under ambient conditions. Specific aims include (i) defect engineering in diamond and systematic characterization of nuclear polarization buildup; (ii) development of novel, enhanced spin polarization transfer schemes tailored to both single-crystal and powdered diamond; and (iii) proof-of-principle demonstrations of polarization transfer from diamond to solid and fluid targets. The approach employs low magnetic fields (~10 mT), ambient (or near-ambient) temperature, and mild optical excitation, circumventing the need for complex, expensive hardware while offering regimes of spin polarization dynamics not explored in the past. The partnership with Delaware Diamond Knives is providing access to a broad set of diamond samples, whose characteristics (nitrogen content, 13C enrichment, surface termination, single crystal or variable-particle-size powder, etc.) are specifically tailored to attain optimal polarization transfer. The work aims to enable studies of molecular moieties in trace concentrations (typical in biochemistry), investigation of mass-limited systems (often found in synthetic chemistry), and high-throughput characterization of molecular libraries (as required in the pharmaceutical industry).
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.