Perspectives of functionalized probes in SNOM and TERS. E.G. Bortchagovsky 1, U. Fischer 2, T. Schmid 3, and R. Zenobi 3 1 Institute of Semiconductor Physics of NAS of Ukraine, pr.Nauki 41, Kiev 03028, Ukraine 2 Physikalisches Institut, Westfälischen Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 10, Münster, Germany 3 Laboratorium für Organische Chemie, ETH Zürich, CH-8093 Zürich, Switzerland Funcrionalized tip – Raman probe Raman signal of functionalized tips should depend on their local environment. TERS of molecules adsorbed on a surface (black) and on a tip (red). Red spectra are intentionally shifted by 20 cm −1 + results for molecules deposited on or picked up by tips of B.Pettinger or T.Schmid and R.Zenobi Molecules on tips also give recordable TERS signal. Stains allMalachite greenThiophenol “equidistant” (?)   8.4 cm -1   6 cm -1 2 d point Tip covered by thiophenol, substrate – clean fresh striped-off gold Different points1 st point Spectra at different points have visible differences and even the position of lines are slightly different. Spectra at the same point are reproducible even in subtle details. Perspectives Reaction on: - field intensity; - chemical binding; - physical binding; - conformation; - mechanical forces; … Internal standard for TERS pH-sensitiv 4-mercaptobenzoic acid Monitoring of single proton pump? Chemical binding molecular recognition by specific binding complimentary single strands of a DNA – binding No binding! It exhibits in Raman spectra! TERS-assisted force spectroscopy! molecular recognition! Physical bindingStructural conformation retinol Even fatty acids demonstrate such a behavior Molecular ruler Fantastic? But: O-46 Tapping AFM based TERS microscopy for high resolution Raman analysis Taro Ichimura Osaka University profiling spectral change due to force effect - low EM enhancement - enhanced only in contact region attributed to force effect - low EM enhancement - enhanced only in contact region attributed to force effect G-band Raman shift [cm -1 ] tip-sample distance [nm] integration of G-band intensity integration of G-band intensity ◆ sample: SWNT (different from the previous one) Ref.: Yano, et al. Nano Lett. (2006). far near d : tip-sample distance T. Ichimura, T. Yano, P. Verma, S. Kawata NFO-11 Standard Raman is the analytical method but enhanced Raman is not! Intensity is defined by “the amount of an analyte” x “local enhancement” It is necessary to determine the distribution of the local enhancement! Possible solution is the constant amount of an reference material at each point of measurements. Inclusion of it into the substrate or substrate material – suffer from roughness; deposition of it on the surface – no guaranty of the uniformity and contamination; delivering of it on a tip – elegant solution! All normalized results differ from the registered maps of the Raman signal from specimens. Areas covered by specimens but hidden by low enhancement are revealed demonstrating the real relative distribution.. E.B. acknowledges a guest fellowship from the German Research Council (DFG) and Swiss National Science Foundation. E. G. Bortchagovsky and U. C. Fischer, “The concept of a near-field Raman probe” Nanoscale 4 (2012) E. Bortchagovsky, T. Schmid and R. Zenobi, “Internal standard for tip- enhanced Raman spectroscopy”, Appl. Phys. Lett. 103 (2013)