Berlin 2015 – wissenschaftliches Programm
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MI: Fachverband Mikrosonden
MI 4: On-Surface Polymerization (contributed Session to the Symposium SYOP, joint Session with CPP)
MI 4.2: Vortrag
Dienstag, 17. März 2015, 09:45–10:00, C 243
Polymerization of polyelectrolyte poly-L-lysine on charge-patterned silicon wafers — •Heidemarie Schmidt1, Martin Müller2, K. Wiesenhütter3, B. Urban2, A.-D. Müller4, I. Skorupa1,3, W. Skorupa3, M. Rüb5, and O.G. Schmidt1,6 — 1TU Chemnitz — 2IPF Dresden — 3HZDR — 4Anfatec Instruments AG — 5FH Jena — 6IFW Dresden
The local modification of silicon surfaces by adsorbing polyelectrolytes has been predicted to become ubiquitous in the engineering of smart carriers for biosensors, tissue engineering, and directed cell growth [1]. We have implanted phosphorous ions in ca. 200-1000 nm thick layers of a silicon wafer, in order to realize a defined stripe-like microscopic pattern of surface-near electrostatic forces [2]. The estimated density of localized charges between the ca. 2-3 nm thick native silicon dioxide and the silicon wafer ranges from 10^14 to 10^18 m^-2 and is much larger and stable than charges from silanol groups at an ordinary silicon dioxide surface. Using combined Atomic and Kelvin probe force microscopy measurements we could show that cationic model polyelectrolyte poly-L-lysine (PLL) [3] with a single chain length of 200 nm is preferentially adsorbed in agglomerates with chain lengths of 1-2 micrometer on the implanted microsized regions of the silicon carrier at pH = 11. The unimplanted regions of the silicon wafer were comparatively weakly adsorbing the PLL. [1] H. Schmidt et al., Appl. Surf. Sci. 281 (2013) 24-29, [2] C. Baumgart et al., Phys. Rev. B. 80 (2009) 085305, [3] Advances in Polymer Science 255 & 256 (Ed.: Martin Müller), Springer, 2014