This lecture will introduce how tip-enhanced Raman spectroscopy (TERS)can be used for analytical applications, in particular to investigate the nanometer scale spatial organization of delicate 2-dimensional molecular systems. TERSis ideally suited for this purpose because itoffers excellent spatial resolution (≈ 10 nm) and sensitivity (down to single molecules for strong Raman scatterers), spectroscopic identification of molecular species without any labelling, and the ability to work in situ. In fact, TERS has become the method of choice for studying nanoscale defects, strain, and edge effects in graphene and carbon nanotubes. However, these are robust materials that are not easily decomposed by intense local electromagnetic fields. In contrast, sensitive 2D structures such as synthetic 2D-polymers and biological membranes and their components (lipids, proteins, glycans) are notoriously difficult to study by TERS, because extended laser irradiation and intense local fields lead to their decomposition. Thus, powerful methods for their analysis and imaging with molecular selectivity and sufficient spatial resolution are still lacking. Conducting TERS experiments in liquids (the natural environment for membranes), the use of protected tips, and a new proposal to carry out TERS in a pulsed fashion are methodological innovations that should expand the scope of materials accessible to investigation by TERS. These innovations are expected to solve the problem of energy dissipation and avoid photodamage, currently the major limitation for performing high-resolution TERS on delicate chemical and biological systems.
Prof. Renato Zenobi was born in Zurich in 1961, received a M.S. degree from the ETH Zurich in 1986, and a Ph.D. at Stanford University in the USA in 1990. This was followed by two postdoctoral appointments at the University of Pittsburgh (1990 - 1991) and at the University of Michigan (1991). Prof. Zenobi returned to Switzerland in 1992 as a Werner Fellow at the EPFL, Lausanne where he is a full professor of Analytical Chemistry at ETH Zürich since 2000. He was chairman of the Organic Chemistry Laboratory in 2002-2003 and 2011-2012, served as the president of ETH’s university assembly from 2006-2008, and of the lecturer’s conference at ETH Zürich from 2006-2010. In 2010 he was appointed Associate Editor of Analytical Chemistry (American Chemical Society). His research areas include laser-based analytical chemistry, electrospray and laser-assisted mass spectrometry, ambient mass spectrometry, and near-field optical microscopy and spectroscopy. He has made important contributions to the understanding of the ion formation mechanism in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, and to ambient ionization methods. He is well known for the development of analytical tools for the nanoscale, in particular TERS (tip-enhanced Raman spectroscopy), a spectroscopic methodology with ≈ 10 nm spatial resolution.
Prof. Zenobi has received many awards for his scientific work, including the Thomas Hirschfeld Award (1989), an Andrew Mellon Fellowship (1990), the Ruzicka Prize (1993), the Heinrich Emanuel Merck-Prize (1998), the Redwood Lectureship from the Royal Society of Chemistry (2005), the Michael Widmer Award (2006), a honorary Professorship at East China Institute of Technology (2007), the Schulich Graduate Lectureship (2009), a honorary membership of the Israel Chemical Society (2009), honorary professorships at the Chinese Academy of Sciences (Changchun), at Hunan University, and at Changchun University of Chinese Medicine (2010), the Mayent-Rothschild Fellowship (Institut Curie, Paris; 2010), the Fresenius Lectureship from the German Chemical Society (2012), the Thomson Medal (International Mass Spectrometry Foundation, 2014), the RUSNANO prize (2014), the Fresenius Prize (German Chemical Society, 2015) and Xing Da Lectureship at Peking University (2017).