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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 12: Organic Thin Films
CPP 12.10: Vortrag
Montag, 16. März 2015, 17:45–18:00, H 2032
Cross-linking-induced disappearance of surface-enhanced Raman scattering in aromatic self-assembled monolayers — •André Beyer1, Marcel Mainka1, Xianghui Zhang1, Thomas Huser2, and Armin Gölzhäuser1 — 1Physics of Supramolecular Systems, University of Bielefeld, 33615 Bielefeld, Germany — 2Biomolecular Photonics, University of Bielefeld, 33615 Bielefeld, Germany
Surface-enhanced Raman scattering (SERS) spectra from aromatic self-assembled monolayers (SAMs) were recorded with the assistance of gold nanoparticles in different geometries. SAMs on planar gold surfaces with gold nanoparticles on top as well as SAMs on gold nanoparticles yielded comparable spectra with high signal-to-noise ratios. The cross-linking of aromatic SAMs by electron exposure results in the formation of carbon nanomembranes (CNMs). We demonstrate the formation of CNM-shells due to electron exposure of SAM-covered gold nanoparticles. Surprisingly, no Raman scattering in the range between 200 – 3100 cm−1 was detectable from any aromatic SAM after cross-linking in the different SERS detection geometries. This finding was supported by performing SERS measurements on CNM/SAM samples which yielded no signal from the CNM but an intense signal from the SAM. Implications, possible mechanisms, and potential applications of this effect will be discussed.