title: Facile and rapid direct gold surface immobilization with controlled orientation for carbohydrates.
abstract: Effective surface immobilization is a prerequisite for numerous carbohydrate-related studies including carbohydrate-biomolecule interactions. In the present work, we report a simple and rapid modification technique for diverse carbohydrate types in which direct oriented immobilization onto a gold surface is accomplished by coupling the amine group of a thiol group-bearing aminophenyl disulfide as a new coupling reagent with an aldehyde group of the terminal reducing sugar in the carbohydrate. To demonstrate the generality of this proposed reductive amination method, we examined its use for three types of carbohydrates: glucose (monosaccharide), lactose (disaccharide), and GM1 pentasaccharide. Through successful mass identifications of the modified carbohydrates, direct binding assays on gold surface using surface plasmon resonance and electrochemical methods, and a terminal galactose-binding lectin assay using atomic force microscopy, we confirmed several advantages including direct and rapid one-step immobilization onto a gold surface and exposure of functional carbohydrate moieties through oriented modification of the terminal reducing sugar. Therefore, this facile modification and immobilization method can be successfully used for diverse biomimetic studies of carbohydrates, including carbohydrate-biomolecule interactions and carbohydrate sensor or array development for diagnosis and screening.
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Korea.
authors.forename: Jeong Hyun
authors.initials: JH
authors.lastname: Seo
authors.forename: Kyouichi
authors.initials: K
authors.lastname: Adachi
authors.forename: Bong Kuk
authors.initials: BK
authors.lastname: Lee
authors.forename: Dong Gyun
authors.initials: DG
authors.lastname: Kang
authors.forename: Yeon Kyu
authors.initials: YK
authors.lastname: Kim
authors.forename: Kyoung Ro
authors.initials: KR
authors.lastname: Kim
authors.forename: Hea Yeon
authors.initials: HY
authors.lastname: Lee
authors.forename: Tomoji
authors.initials: T
authors.lastname: Kawai
authors.forename: Hyung Joon
authors.initials: HJ
authors.lastname: Cha
mesh_terms: D002241:Carbohydrates / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D015394:Molecular Structure; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D020349:Surface Plasmon Resonance; D013499:Surface Properties; D013997:Time Factors
chemical_list: D002241:Carbohydrates; D005663:Furans; D006046:Gold