title: Longitudinal diffusion behavior of hemicyanine dyes across phospholipid vesicle membranes as studied by second-harmonic generation and fluorescence spectroscopies.
abstract: The adsorption and longitudinal diffusion behaviors of a series of hemicyanine dyes to phospholipid vesicle membranes were studied by second-harmonic generation (SHG) and fluorescence spectroscopies. It was observed that the longitudinal diffusion of cationic hemicyanine dyes takes place immediately after the initial adsorption of these dyes to the outer surface of the vesicle membrane. In contrast, hardly any amount of a zwitterionic hemicyanine dye with a sulfonate group diffused across the vesicle membrane within the measurement time (<2000 s). Based on the difference in the time-course responses of SHG and fluorescence spectroscopies for all of the hemicyanine dyes tested, we propose that hydration of the sulfonate group is mainly responsible for the low diffusivity of the zwitterionic hemicyanine dye.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan. akira@anal.chem.tohoku.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Yamaguchi
authors.forename: Masaki
authors.initials: M
authors.lastname: Nakano
authors.forename: Kimihisa
authors.initials: K
authors.lastname: Nochi
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Yamashita
authors.forename: Kotaro
authors.initials: K
authors.lastname: Morita
authors.forename: Norio
authors.initials: N
authors.lastname: Teramae
mesh_terms: D002232:Carbocyanines / Q000737:chemistry* / Q000145:classification; D004058:Diffusion; D005456:Fluorescent Dyes; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D015394:Molecular Structure; D010743:Phospholipids / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D002232:Carbocyanines; D005456:Fluorescent Dyes; D008051:Lipid Bilayers; D008081:Liposomes; D010743:Phospholipids