Berlin 2012 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 15: Graphene: Structure and Theory I

HL 15.1: Talk

Monday, March 26, 2012, 15:00–15:15, EW 201

Functional Polymer Brushes on Graphene — •Max Seifert¹, Amelie Koch¹, Frank Deubel², Tobias Simmet¹, Lucas Hess¹, Martin Stutzmann¹, Ian Sharp¹, and Jose Antonio Garrido¹ — ¹Walter Schottky Institut, TU München, Germany — ²Wacker-Lehrstuhl für Makromolekulare Chemie, TU München, Germany

The use of graphene in biosensing applications requires a well-defined functionalization method in order to introduce sensing specificity and improve device sensitivity. It has been shown that direct photo-grafting and photo-polymerization of styrene yields covalently bound polystyrene brushes on graphene without significantly disrupting its basal plane conjugation. We have previously suggested that hydrogen-containing defects sites can act as initiation centers for the surface polymerization. In this contribution, we demonstrate by Raman spectroscopy that the density of such hydrogen defect sites can be finely controlled by exposing the pristine CVD grown graphene sheets to a hydrogen plasma at room temperature, resulting in a tunable polymer brush grafting density. However, pure polystyrene brushes exhibit very low chemical reactivity for further functionalization. Thus, we have developed a procedure for the copolymerization of styrene and different acrylates, paving the way towards a graphene-based platform for highly sensitive and specific biosensor devices.