Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, 10691, Stockholm, Sweden.
Angew Chem Int Ed Engl. 2017 May 8;56(20):5561-5564. doi: 10.1002/anie.201702263. Epub 2017 Apr 10.
The importance of identifying DNA bases at the single-molecule level is well recognized for many biological applications. Although such identification can be achieved by electrical measurements using special setups, it is still not possible to identify single bases in real space by optical means owing to the diffraction limit. Herein, we demonstrate the outstanding ability of scanning tunneling microscope (STM)-controlled non-resonant tip-enhanced Raman scattering (TERS) to unambiguously distinguish two individual complementary DNA bases (adenine and thymine) with a spatial resolution down to 0.9 nm. The distinct Raman fingerprints identified for the two molecules allow to differentiate in real space individual DNA bases in coupled base pairs. The demonstrated ability of non-resonant Raman scattering with super-high spatial resolution will significantly extend the applicability of TERS, opening up new routes for single-molecule DNA sequencing.
在许多生物学应用中，识别单分子水平的 DNA 碱基的重要性是众所周知的。尽管可以通过特殊设置的电学测量来实现这种识别，但由于衍射极限，仍然不可能通过光学手段在真空中识别单个碱基。在此，我们展示了扫描隧道显微镜（STM）控制的非共振尖端增强拉曼散射（TERS）的卓越能力，能够以低至 0.9nm 的空间分辨率明确区分两个单独的互补 DNA 碱基（腺嘌呤和胸腺嘧啶）。为这两种分子鉴定的独特拉曼指纹可以区分在真空中相互偶联的碱基对中的单个 DNA 碱基。所展示的具有超高空间分辨率的非共振拉曼散射的能力将极大地扩展 TERS 的适用性，为单分子 DNA 测序开辟新途径。
