Karl Franzens University Graz
Graz University of Technology
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Karl Franzens University Graz | Graz University of Technology | |
Structure and Self‐organization of Organic and Bio‐molecules Deposited on Surfaces: From Fundamental Information towards Real Applications Self-assembly and self-organization of molecules are the main strategies used in nature to permit life to emerge from its building blocks, and have inspired new trends in nanotechnology based on a bottom-up approach. Understanding the structure of molecular layers on surfaces is of a great importance because its atomic arrangement determines the mechanical properties, electronic behavior and reactivity of surfaces. Surface science techniques, XPS, LEED, DFT and particularly STM, present a great sensitivity that make them suitable to find out structure, chemical interaction and growth mode of molecular layers on surfaces. The kind of molecule-surface bonding is one of the key-points for the molecular structure. In this presentation we will review different complex molecular systems on surfaces, and we will classify them by the strength of the molecule-surface interaction. Single layers of PTCDA molecules on single-crystal metal surfaces, as Au(111), are an example of a low-interacting system, in which we can tailor the dimensionality of the layer [1] Another interesting systems are the bio-molecules covalently bound to metallic surfaces through a thiol-motif [3]. Particularly we will see a basic case of cysteine on gold, and an application derived from it, as self-assembled layers of DNA and PNA on gold for biosensing applications. We look to correlate the structural properties of the layer with the biosensing activity. We have found that molecular orientation of PNAs strongly depends on surface coverage and the interaction with the substrate [2]. At last we will focus on a highly interacting systems. A surface catalyzed cyclodehydrogenation process of polycyclic aromatic hydrocarbons can be used form fullerenes and other related materials directly on surfaces[4]. This reaction at surfaces emerges as a new methodology for a rational synthesis of fullerenes. |