SYMPOSIUM ON SURFACE SCIENCE 2011 Baqueira Beret, Lleida ...

Janus nanomembranes:
Surfaces without bulk, functionalized on both sides
Zhikun Zheng 1 , Christoph T. Nottbohm 1 , Andrey Turchanin 1 ,
Heiko Muzik 1 , André Beyer 1 , Mike Heilemann 1 , Markus Sauer 2 , Armin Gölzhäuser 1
1 Department of Physics, University of Bielefeld, Germany
2 Biotechnology & Biophysics, Julius-Maximilians-University Würzburg, Germany
A 1 nm thick free-standing membrane with amino functionalities on its top side and thiol
functionalities on its bottom side was fabricated from aromatic self-assembled monolayers.
It is demonstrated that such a bifacial Janus[1] membrane, is in fact a surface without a
bulk that can act as a two dimensional platform for the selective immobilization of
functional molecules[2]. We have functionalized both sides with different fluorescent
molecules: The amino side of the membrane is modified with tetramethylrhodamine
(TMR), the thiol side is functionalized with ATTO647N, cf. Fig.1. The successful
immobilization of molecules is proven by XPS. Functionalized Janus nanomembranes
cover areas up to several mm 2 and can be suspended over metal grids allowing a simple
fluorescence detection, cf. Fig. 2. The potential of functionalized Janus nanomembranes as
generic platform for two-dimensional directional chemistry is discussed.
[1] Janus is a Roman god with two faces, see below.
[2] Z. Zheng, C. T. Nottbohm, A. Turchanin, H. Muzik, A. Beyer, M. Heilemann, M. Sauer, A.
Gölzhäuser: Janus nanomembranes: A generic platform for chemistry in two dimensions, Angewandte
Chemie Intl. Ed. , 49, 8493 (2010).
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