title: Protein adsorption to graphene surfaces controlled by chemical modification of the substrate surfaces.
abstract: We have investigated effects of the support substrate surfaces on properties of the attached graphene flakes by observing protein adsorption to the graphene surfaces on SiO2/Si substrates that are modified with self-assembled monolayers to control their hydrophilicity. Using atomic force microscopy operated in aqueous environment, we found that high-density clusters of agglomerated avidin molecules form on the graphene flakes in the areas supported by a hydrophobic substrate surface, whereas very low density of large avidin clusters form at the edge of graphene flakes in the area supported by a hydrophilic surface. These results demonstrate that hydrophilicity of the support surface affects hydrophilicity of the graphene surface also in aqueous environment and that surface modification of the support substrate is a useful technique to control protein adsorption phenomena on graphene surfaces for realization of high sensitive graphene biosensors.
authors.affiliation: Yokohama National University, 79-5, Tokiwadai, Hodogaya, Yokohama 240-8501, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Kamiya
authors.affiliation: Yokohama National University, 79-5, Tokiwadai, Hodogaya, Yokohama 240-8501, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamazaki
authors.affiliation: Yokohama National University, 79-5, Tokiwadai, Hodogaya, Yokohama 240-8501, Japan. Electronic address: togino@ynu.ac.jp.
authors.forename: Toshio
authors.initials: T
authors.lastname: Ogino
mesh_terms: D000327:Adsorption; D001360:Avidin / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods; D006108:Graphite / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions
chemical_list: D001360:Avidin; D006108:Graphite
keywords: Biointerfaces; Graphene; Protein adsorption; Self-assembled monolayers