Probing molecular dynamics at the nanoscale via an individual paramagnetic centre

Authors

T. Staudacher, University of Stuttgart
N. Raatz, University of Leipzig
S. Pezzagna, University of Leipzig
J. Meijer, University of Leipzig
F. Reinhard, University of Stuttgart
C. A. Meriles, CUNY City CollegeFollow
J. Wrachtrup, University of Stuttgart

Document Type

Article

Publication Date

October 2015

Abstract

We demonstrate a protocol using individual nitrogen-vacancy centres in diamond to observe the time evolution of proton spins from organic molecules located a few nanometres from the diamond surface. The protocol records temporal correlations among the interacting protons, and thus is sensitive to the local dynamics via its impact on the nuclear spin relaxation and interaction with the nitrogen vacancy. We gather information on the nanoscale rotational and translational diffusion dynamics by analysing the time dependence of the nuclear magnetic resonance signal. Applying this technique to liquid and solid samples, we find evidence that liquid samples form a semi-solid layer of 1.5-nm thickness on the surface of diamond, where translational diffusion is suppressed while rotational diffusion remains present. Extensions of the present technique could be exploited to highlight the chemical composition of molecules tethered to the diamond surface or to investigate thermally or chemically activated dynamical processes such as molecular folding.

Comments

This work was originally published in Nature Communicatins, available at doi:10.1038/ncomms9527.