我们请到了瑞士联邦理工（ETH Zurich）Renato Zenobi教授来bw必威西汉姆联官网交流访问。Zenobi教授将于11月15日（周五）上午10:00在唐仲英楼B501做题为“Chemical Analysis on the Nanometer Scale”的学术报告，欢迎各位老师及同学参加！
Zenobi教授是近场光学（Near-field Optics）和质谱（Mass Spectrometry）领域的国际知名学者。是针尖增强拉曼光谱学（Tip-enhanced Raman spectroscopy）的主要发明人，在质谱离子源的机理与应用等方向作出过杰出贡献。Zenobi教授是ETH的分析中心创建人之一，并于1995-2007年任中心主任；2010至今，任美国化学会Analytical Chemistry杂志编委。
报告题目：Chemical Analysis on the Nanometer Scale
摘要：
In this presentation, I will discuss the development optical near-field methods to obtain molecular information on the nanometer scale. The talk will focus on Tip-enhanced Raman Spectroscopy (TERS) and near-field laser ablation-mass spectrometry (LA-MS).
TERS is the spectroscopic “cousin” of AFM and STM. The principle is very similar to SERS, where metallic nanostructures on a surface, onto which a sample film is deposited, leads to a huge enhancement (1000 – 10^6 times) of the normally quite weak Raman scattering. TERS can be viewed as “SERS upside down”: instead of bringing the sample to the enhancing SERS substrate, a single metallic nanostructure is brought by means of a scanning microscope tip to the sample of interest. With the introduction of highly enhancing TERS tips, fast CCD detectors, and advanced scanning probe microscopy techniques, true spectroscopic imaging has become a reality. Images can now be recorded with full spectral information at every pixel, using large pixel numbers, within minutes. This will be exemplified with spectroscopic maps obtained on mixed dye layers, segregated lipid domains, self-assembled monolayers, and graphene.
In LA-MS, pulsed laser ablation is performed at atmospheric conditions via a near-field optical probe, followed by ionization of the ablation products and transport into a mass spectrometer for analysis. The key challenge lies in the extremely small amount of material that is available for analysis, and the sometimes inefficient transport of ions. This can be addressed by an "active" interface that performs both functions, ion formation and transport, at the same time.
