Nanodiamond(ND)polarizer can be used for dynamic nuclear polarization(DNP),owing to unpaired electrons provided by surface defects.However,^(1)H enhancement via Overhauser DNP(ODNP)using ND in-situ liquid has been fou...Nanodiamond(ND)polarizer can be used for dynamic nuclear polarization(DNP),owing to unpaired electrons provided by surface defects.However,^(1)H enhancement via Overhauser DNP(ODNP)using ND in-situ liquid has been found much smaller than traditional radicals.Herein,we study the surface properties of ND using electron spin resonance(ESR)and Raman methods firstly.Then the enhancement of^(1)H ODNP is explored using ND as polarizer with different nanoparticle sizes and concentrations at home-built 0.06 T DNP spectrometer.The surface of ND with the size of 30 nm is further modification via high temperature air oxidized and the enhancement was measured.The results show that nanoparticle sizes and Raman peak intensity ratio of sp^(2)/sp^(3)hybridization are approximate negative correlation and positive correlation to enhancement,respectively.Furthermore,there is no significant enhancement in the oxidation group,and a−22.5-fold^(1)H ODNP enhancement is achieved in-situ liquid at room temperature,which demonstrate the ND can be used as an efficient enhancer.We expect ND to play a greater role in biomedical research,especially for multimodal imaging with improving the performance of ND surface.展开更多
基金supported by the National key of R&D Program of China(No.2018YFC0115000)the National Major Scientific Research Equipment Development Project of China(No.81627901)+3 种基金the Chinese Academy of Sciences(Nos.YZ201677,YZ201551,KFJ-STS-QYZD-169)the National Natural Science Foundation of China(No.11575287,11705274)Major Scientific and Technological Innovation Project in Hubei(No.2019AAA023)Application Foundation Frontier Project of WuHan(No.2019020701011450).
文摘Nanodiamond(ND)polarizer can be used for dynamic nuclear polarization(DNP),owing to unpaired electrons provided by surface defects.However,^(1)H enhancement via Overhauser DNP(ODNP)using ND in-situ liquid has been found much smaller than traditional radicals.Herein,we study the surface properties of ND using electron spin resonance(ESR)and Raman methods firstly.Then the enhancement of^(1)H ODNP is explored using ND as polarizer with different nanoparticle sizes and concentrations at home-built 0.06 T DNP spectrometer.The surface of ND with the size of 30 nm is further modification via high temperature air oxidized and the enhancement was measured.The results show that nanoparticle sizes and Raman peak intensity ratio of sp^(2)/sp^(3)hybridization are approximate negative correlation and positive correlation to enhancement,respectively.Furthermore,there is no significant enhancement in the oxidation group,and a−22.5-fold^(1)H ODNP enhancement is achieved in-situ liquid at room temperature,which demonstrate the ND can be used as an efficient enhancer.We expect ND to play a greater role in biomedical research,especially for multimodal imaging with improving the performance of ND surface.
