title: Combined use of two membrane-potential-sensitive dyes for determination of the Galvani potential difference across a biomimetic oil/water interface.
abstract: The fluorescence behavior of anionic membrane-potential-sensitive dyes, bis-(1,3-dibutylbarbituric acid) trimethine oxonol (DiBAC4(3)) and bis-(1,3-diethylthiobarbituric acid)trimethine oxonol (DiSBAC2(3)), at a biomimetic 1,2-dichloroethane (DCE)/water (W) interface was studied by the mean of potential-modulated fluorescence (PMF) spectroscopy. The respective dyes gave a well-defined PMF signal due to the adsorption/desorption at the DCE/W interface. It was also found that the potentials where the two dyes gave the PMF signals were different by about 100 mV. We then attempted a combined use of the two dyes for determination of the Galvani potential difference across the DCE/W interface. When 40 μM DiBAC4(3) and 15 μM DiSBAC2(3) were initially added to the W phase, distinctly different spectra were obtained for different interfacial potentials. The ratio of the PMF signal intensities at 530 and 575 nm (the fluorescence maximum wavelengths for the respective dyes) showed a clear dependence on the interfacial potential. These results suggested the potential utility of the combined use of two dyes for the determination of membrane potentials in vivo.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kobe University, Nada, Kobe, 657-8501, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Yoshimura
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Nagatani
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Osakai
mesh_terms: D000327:Adsorption; D001463:Barbiturates / Q000737:chemistry*; D032701:Biomimetics; D002623:Chemistry Techniques, Analytical; D004563:Electrochemistry; D005025:Ethylene Dichlorides / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D007555:Isoxazoles / Q000737:chemistry*; D008564:Membrane Potentials; D015394:Molecular Structure; D009821:Oils; D013050:Spectrometry, Fluorescence; D014867:Water / Q000737:chemistry
chemical_list: D001463:Barbiturates; D005025:Ethylene Dichlorides; D005456:Fluorescent Dyes; D007555:Isoxazoles; D009821:Oils; D014867:Water; C052795:bis(1,3-dibutylbarbiturate)trimethine oxonol; C024565:ethylene dichloride