TY  - JOUR
AU  - Schmidt, Andreas
AU  - Adelabu, Isaiah
AU  - Nelson, Christopher
AU  - Nantogma, Shiraz
AU  - Kiselev, Valerij G
AU  - Zaitsev, Maxim
AU  - Abdurraheem, Abubakar
AU  - de Maissin, Henri
AU  - Rosen, Matthew S
AU  - Lehmkuhl, Sören
AU  - Appelt, Stephan
AU  - Theis, Thomas
AU  - Chekmenev, Eduard Y
TI  - 13C Radiofrequency Amplification by Stimulated Emission of Radiation Threshold Sensing of Chemical Reactions.
JO  - Journal of the American Chemical Society
VL  - 145
IS  - 20
SN  - 0002-7863
CY  - Washington, DC
PB  - ACS Publications
M1  - DKFZ-2023-00963
SP  - 11121-11129
PY  - 2023
N1  - 2023 May 24;145(20):11121-11129
AB  - Conventional nuclear magnetic resonance (NMR) enables detection of chemicals and their transformations by exciting nuclear spin ensembles with a radio-frequency pulse followed by detection of the precessing spins at their characteristic frequencies. The detected frequencies report on chemical reactions in real time and the signal amplitudes scale with concentrations of products and reactants. Here, we employ Radiofrequency Amplification by Stimulated Emission of Radiation (RASER), a quantum phenomenon producing coherent emission of 13C signals, to detect chemical transformations. The 13C signals are emitted by the negatively hyperpolarized biomolecules without external radio frequency pulses and without any background signal from other, nonhyperpolarized spins in the ensemble. Here, we studied the hydrolysis of hyperpolarized ethyl-[1-13C]acetate to hyperpolarized [1-13C]acetate, which was analyzed as a model system by conventional NMR and 13C RASER. The chemical transformation of 13C RASER-active species leads to complete and abrupt disappearance of reactant signals and delayed, abrupt reappearance of a frequency-shifted RASER signal without destroying 13C polarization. The experimentally observed 'quantum' RASER threshold is supported by simulations.
LB  - PUB:(DE-HGF)16
C6  - pmid:37172079
DO  - DOI:10.1021/jacs.3c00776
UR  - https://inrepo02.dkfz.de/record/276057
ER  -