title: Graft linker immobilization for spatial control of protein immobilization inside fused microchips.
abstract: Fused silica glass microchips have several attractive features for lab-on-a-chip applications; they can be machined with excellent precision down to nanospace; are stable; transparent and can be modified with a range of silanization agents to change channel surface properties. For immobilization, however, ligands must be added after bonding, since the harsh bonding conditions using heat or hydrofluoric acid would remove all prior immobilized ligands. For spatial control over immobilization, UV-mediated immobilization offers several advantages; spots can be created in parallel, the feature size can be made small, and spatial control over patterns and positions is excellent. However, UV sensitive groups are often based on hydrophobic chemical moieties, which unfortunately result in greater non-specific binding of biomolecules, especially proteins. Here, we present techniques in which any -CH(x) (x=1,2,3) containing surface coating can be used as foundation for grafting a hydrophilic linker with a chemical anchor, a carboxyl group, to which proteins and amine containing molecules can be covalently coupled. Hence, the attractive features of many well-known protein and biomolecule repelling polymer coatings can be utilized while achieving site-specific immobilization only to pre-determined areas within the bonded microchips.
authors.affiliation: Department of Applied Chemistry, School of Engineering, The University of Tokyo, Hongo, Bunkyo, Tokyo, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Shirai
authors.forename: Björn
authors.initials: B
authors.lastname: Renberg
authors.forename: Kae
authors.initials: K
authors.lastname: Sato
authors.forename: Kazuma
authors.initials: K
authors.lastname: Mawatari
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Konno
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ishihara
authors.forename: Takehiko
authors.initials: T
authors.lastname: Kitamori
mesh_terms: D020100:Hydrogels; D056656:Lab-On-A-Chip Devices; D011506:Proteins / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D020100:Hydrogels; D011506:Proteins