Lafon, O., Rosay, M., Aussenac, F., Lu, X., Trébosc, J., Cristini, O., Kinowski, C., Touati, N., Vezin, H., and Amoureux, J.-P. (2011) Beyond the Silica Surface by Direct Silicon-29 Dynamic Nuclear Polarization, Angew. Chem. Int. Ed., n/a-n/a.
http://dx.doi.org/10.1002/anie.201101841
Buried truth: High-field magic angle spinning dynamic nuclear polarization (MAS DNP) enhances the sensitivity of solid-state NMR spectroscopy, but only for protonated surfaces. Direct 29Si DNP using the biradical TOTAPOL circumvents this limitation by producing a 30-fold enhancement of subsurface 29Si NMR signals in mesoporous silica, a material with applications in photonics, nanotechnology and catalysis.