学术活动发布与订制系统

Visualizing individual molecules with chemical recognition is a longstanding target in catalysis, bio-science, nanotechnology, and materials science. Molecular vibrations provide a valuable “fingerprint” for this identification. The spectroscopy based on tip-enhanced Raman scattering (TERS) has opened a path to obtain enhanced vibrational signals thanks to the strong localized plasmonic field originated at the tip apex. In this talk, I shall demonstrate single-molecule Raman spectroscopic mapping with unprecedented spatial resolution down to sub-nm, resolving even the inner structure of a single molecule and its configuration on the surface [1]. This is achieved by a delicate spectral-matching technique that invokes a double-resonance process and resultant nonlinear optical effect, thanks to the exquisite tuning capability provided by low-temperature ultrahigh-vacuum scanning tunneling microscopy. Our nonlinear TERS technique features the use of only a continuous wave laser rather than two pulse lasers. The central message delivered from our findings is: Raman spectromicroscopy has gone intra-molecular and sub-nanometer, which opens up a new avenue to probe surface chemical reactions, nonlinear optical processes, photochemistry, and bio-imaging at the single-molecule scale.

[1] R. Zhang, Y. Zhang, Z. C. Dong*, S. Jiang, C. Zhang, L. G. Chen, L. Zhang, Y. Liao, J. Aizpurua, Y. Luo, J. L. Yang , and J. G. Hou*, "Chemical mapping of a single molecule by plasmon enhanced Raman scattering", Nature 498 (2013) 82-86.

Dr. Zhen-Chao Dong is currently a full professor at Hefei National Laboratory for Physical Sciences at the Microscale (HFNL), University of Science and Technology of China (USTC). He graduated from Sichuan University in 1983 and received his M.S. degree in Xiamen University in 1987. After obtaining his Ph.D. from Fujian Institute on the Structure of Matter, Chinese Academy of Sciences in 1990, he worked in the same institute as an assistant professor. From 1992 to 1995, he was a postdoctoral research associate at Iowa State University / Ames Laboratory, USA. In 1996, he joined the National Institute for Materials Science (NIMS), Japan, where he was appointed as Senior Researcher and later promoted to be Theme Leader. In 2004, Dong joined USTC as a full professor. He is now serving as the Director of Division of Atomic and Molecular Sciences at HFNL. His research interest is in the field of single-molecule optoelectronics and nanoplasmonics, particularly on STM based single-molecule electroluminescence and single-molecule Raman scattering. The aim of his research is 1) to understand the underlying physics that governs the optoelectronic behavior of single molecules at the nanoscale, particularly on the light manipulation and energy transfer in a plasmonic nano-environment, and 2) to explore scientific basis for future technology related to information, energy, and bio-science. Dong is currently the PI of several research projects supported by the Ministry of Science and Technology, the Chinese Academy of Sciences, and the National Natural Science Foundation of China. He is one of the scientists in China with international influence. He has published more than 120 papers indexed by SCI (H-factor=27), including 8 first-author or corresponding-author papers in Nature, Nature Photonics, Phys. Rev. Lett., J. Am. Chem. Soc., and Angew. Chem. He has presented many invited talks in prestigious international conferences, including APS, ACS, IVC, ICN+T, NFO, NANOMETA, PIER, ChinaNANO, ACSIN/ICSPM, and FOP. He is the recipient of "National Outstanding Scientific and Technological Workers Award" from CAST in 2010 and a couple of other awards and honors in 2013, including "the CAIA Outstanding Award", "USTC President Award for Outstanding Research Achievements", "Top 10 Advances in China's Science" and "Top 10 Advances in Science and Technology of China".