In the present contribution, specifically designed single-stranded DNA (ssDNA) sequences composed of adenine and cytosine were used as nanometric rulers to target the maximum achievable spatial resolution of tip-enhanced Raman spectroscopy (TERS) under ambient conditions. By stepping along a strand with a TERS tip, the obtained spectra allowed for a clear spectral discrimination including conformational information of the nucleobases, and even sharp adenine-cytosine transitions were detected repeatedly with a spatial resolution below 1 nm.
@article{arxiv.1604.06598,
title = {Direct Base-to-Base Transitions in ssDNA Revealed by Tip-Enhanced Raman Scattering},
author = {Xiu-Mei Lin and Tanja Deckert-Gaudig and Prabha Singh and Michael Siegmann and Stephan Kupfer and Zhenglong Zhang and Stefanie Gräfe and Volker Deckert},
journal= {arXiv preprint arXiv:1604.06598},
year = {2016}
}