title: Synthesis and characterization of tri(ethylene oxide)-attached poly(amidoamine) dendrimer layers on gold.
abstract: This paper describes the synthesis of a tri(ethylene oxide)-attached fourth-generation poly(amidoamine) dendrimer (EO3-dendrimer) and the characterization of its layers on gold. NMR analysis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry revealed that about 61 amine groups of a G4 PAMAM dendrimer were covalently conjugated with tri(ethylene oxide) units, accounting for a 95% modification level. Layers of the EO3-dendrimer were formed on gold, and the resulting surface was characterized by infrared reflection absorption spectroscopy, ellipsometry, and contact angle goniometry. The EO3-dendrimer resulted in more hydrophilic and less compact layers with no substantial deformation of the molecule during layer formation by virtue of the EO3 units, compared to a PAMAM dendrimer. Interestingly, the specific binding of avidin to the biotinylated layers of the EO3-dendrimer approached a surface density of 5.2 +/- 0.2 ngmm-2, showing about 92% of full surface coverage. The layers of the EO3-dendrimer were found to be more resistant to nonspecific adsorption of proteins than PAMAM dendrimer layers when bovine serum albumin and serum proteins were tested.
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology 373-1, Kusung-dong, Yusung-ku, Taejon 305-701, South Korea.
authors.forename: Mi-Young
authors.initials: MY
authors.lastname: Hong
authors.forename: Young-Ja
authors.initials: YJ
authors.lastname: Kim
authors.forename: Jae Wook
authors.initials: JW
authors.lastname: Lee
authors.forename: Kimoon
authors.initials: K
authors.lastname: Kim
authors.forename: Jung-Hwa
authors.initials: JH
authors.lastname: Lee
authors.forename: Jong-Shin
authors.initials: JS
authors.lastname: Yoo
authors.forename: Sung-Hun
authors.initials: SH
authors.lastname: Bae
authors.forename: Byong-Seok
authors.initials: BS
authors.lastname: Choi
authors.forename: Hak-Sung
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000327:Adsorption; D000818:Animals; D001360:Avidin / Q000737:chemistry; D001710:Biotin / Q000737:chemistry; D001798:Blood Proteins / Q000737:chemistry; D002417:Cattle; D016650:Fluorescein-5-isothiocyanate; D006046:Gold / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D011108:Polymers / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001798:Blood Proteins; D011108:Polymers; D001360:Avidin; D012710:Serum Albumin, Bovine; D001710:Biotin; D006046:Gold; D016650:Fluorescein-5-isothiocyanate