【摘 要】
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Nanodiamond (ND) polarizer can be used for dynamic nuclear polarization (DNP),owing to unpaired electrons provided by surface defects.However,1H enhancement via Overhauser DNP (ODNP) using ND in-situ liquid has been found much smaller than traditional rad
【机 构】
：
State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics,Wuhan Center for Magneti
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Nanodiamond (ND) polarizer can be used for dynamic nuclear polarization (DNP),owing to unpaired electrons provided by surface defects.However,1H enhancement via Overhauser DNP (ODNP) using ND in-situ liquid has been found much smaller than traditional radicals.Herein,we study the surface prop-erties of ND using electron spin resonance (ESR) and Raman methods firstly.Then the enhancement of 1H 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 sp2/sp3 hybridization are approximate negative correlation and pos-itive correlation to enhancement,respectively.Furthermore,there is no significant enhancement in the oxidation group,and a-22.5-fold 1H 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.
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