Background‐Free Proton NMR Spectroscopy with Radiofrequency Amplification by Stimulated Emission Radiation
Abstract
We report on the utility of Radiofrequency Amplification by Stimulated Emission Radiation (RASER) for background‐free proton detection of hyperpolarized biomolecules. We performed hyperpolarization of ≈0.3 M ethyl acetate via pairwise parahydrogen addition to vinyl acetate. A proton NMR signal with signal‐to‐noise ratio exceeding 100 000 was detected without radio‐frequency excitation at the clinically relevant magnetic field of 1.4 T using a standard (non‐cryogenic) inductive detector with quality factor of Q=68. No proton background signal was observed from protonated solvent (methanol) or other added co‐solvents such as ethanol, water or bovine serum. Moreover, we demonstrate RASER detection without radio‐frequency excitation of a bolus of hyperpolarized contrast agent in biological fluid. Completely background‐free proton detection of hyperpolarized contrast agents in biological media paves the way to new applications in the areas of high‐resolution NMR spectroscopy and in vivo spectroscopy and imaging.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 30, 2021
- Source ID
- 10.1002/ange.202108939
Entities
People
- Baptiste Joalland
- Eduard Y. Chekmenev
- Stephan Appelt
- Thomas Theis
Organizations
- Congressionally Directed Medical Research Programs
- Edward Mallinckrodt Jr. Foundation
- National Cancer Institute
- National Heart, Lung, and Blood Institute
- National Institute of Biomedical Imaging and Bioengineering
- National Science Foundation Directorate for Mathematical & Physical Sciences
- North Carolina Biotechnology Center
- North Carolina State University
- RWTH Aachen University
- Russian Academy of Sciences
- Wayne State University