A. Lesage et al., Surface enhanced NMR Spectroscopy by Dynamic Nuclear Polarization, J. Am. Chem. Soc., 2010, 132(44), 15459-15461
It is shown that surface NMR spectra can be greatly enhanced using dynamic nuclear polarization. Polarization is transferred from the protons of the solvent to the rare nuclei (here carbon-13 at natural isotopic abundance) at the surface, yielding at least a 50-fold signal enhancement for surface species covalently incorporated into a silica framework.