title: Formation of Ordered Phospholipid Monolayer on a Hydrophilically Modified Au(111) Substrate.
abstract: The molecular arrangement of phospholipid molecules was investigated on a hydrophilically modified gold surface within an aqueous solution by scanning tunneling microscopy. By suspending phospholipid (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, POPC) nanoparticles in the aqueous electrolyte surrounding a hydrophilically modified gold (111) substrate with 3-mercaptopropionic acid (SH-C2H4-COOH, 3-MPA), well-ordered adlattices of POPC were observed. Traces of particle fusion were visualized before formation of the adlattice. Addition of cholesterol to the suspension seems to facilitate accommodation of POPC on this surface. The observed unit cells of POPC adlattices had dimensions of 0.5 nm × 1.9-2.5 nm. By high-resolution imaging, each unit cell was discerned to be occupied by one upright POPC molecule. The POPC + cholesterol suspension also leads to formation of a flat integrated POPC layer, which may be a lipid bilayer covering the surface.
authors: RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|Department of Advanced Materials Science, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan.
authors: Hiroaki
authors: H
authors: Shimizu
authors: RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|Department of Advanced Materials Science, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan.
authors: Soichiro
authors: S
authors: Matsunaga
authors: RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors: Taro
authors: T
authors: Yamada
authors: RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors: Toshihide
authors: T
authors: Kobayashi
authors: RIKEN , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|Department of Advanced Materials Science, The University of Tokyo , 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan.
authors: Maki
authors: M
authors: Kawai
keywords: gold single-crystal surface; high-resolution imaging; hydrophilic modification; phospholipid; scanning tunneling microscopy