Spontaneous increasing of sensitivity and resolution in parahydrogen-induced hyperpolarization by RASER  

作　　者：Zeyu Zheng Qiwei Peng Huijun Sun Xinchang Wang Zhong Chen 

机构地区：[1]Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance,Department of Electronic Science,Xiamen University,Xiamen,361005,China [2]State Key Laboratory of Physical Chemistry of Solid Surfaces,Xiamen University,Xiamen,361005,China

出　　处：《Magnetic Resonance Letters》2025年第1期1-11,共11页磁共振快报(英文)

基　　金：supported by the National Natural Science Foundation of China(grant number:22274050);the Shanghai Science and Technology Commission(contract number:23J21900300);the Fundamental Research Funds for the Central Universities.

摘　　要：Enhancing the sensitivity of nuclear magnetic resonance(NMR)technology has been the focus of NMR research for decades,which offers the potential to significantly expand its applications in chemistry,biology,and medical imaging.Parahydrogen-induced polarization(PHIP)emerges as a cost-effective approach to substantially enhance the sensitivity of NMR.Nevertheless,the amplification of the ^(1)H signal in PHIP is susceptible to interference from the thermal polarization state ^(1)H NMR signal.Employing RASER(radiofrequency amplification by stimulated emission of radiation)proves effective in mitigating such interference,which can reduce the linewidth and increase the sensitivity at the same time.In this work,we utilized PHIP and RASER to enhance the signal-to-noise ratio(SNR)of a series of biocompatible alkynyl organic acid molecules.The alkynyl acid with the highest enhancement factor was first identified through PASADENA(parahydrogen and synthesis allow dramatically enhanced nuclear alignment)experiments.Subsequently,RASER experiments were carried out through hyperpolarization of 5-hexynoic acid,exploring its signal characteristics under varying flow rates and pressures.The SNR of proton signals of 5-hexynoic acid surpassed 150,000,an 18.62-fold improvement compared with traditional hyperpolarized signals in PASADENA,and a markedly narrowed linewidth of 0.06 Hz.

关 键 词：Nuclear magnetic resonance Parahydrogen-induced polarization PASADENA RASER Alkynyl acid 

分 类 号：O57[理学—粒子物理与原子核物理]