Potential-modulated fluorescence spectroscopy of the membrane potential-sensitive dye di-4-ANEPPS at the 1,2-dichloroethane/water interface.
The spectrofluorometric behavior of a membrane potential-sensitive dye, 1-(3-sulfonatopropyl)-4-[beta-{2-(di-N-butylamino)-6-naphthyl}vinyl]pyridinium betaine (di-4-ANEPPS), at the polarized 1,2-dichloroethane/water interface was studied by means of potential-modulated fluorescence (PMF) spectroscopy. The results, combined with those from cyclic and alternating current voltammetry, clearly suggested that the dye adsorbed at the interface underwent a reorientation with increasing the interfacial potential, giving a well-developed PMF response as well as a voltammetric response. In addition to the PMF response, another PMF response was observed by addition of dilauroyl phosphatidylcholine (DLPC). This additional response was well explained in terms of a reorientation of di-4-ANEPPS at the interface, which would be induced by the potential-dependent desorption of DLPC from the interface. Thus, the present study supported the reorientation/solvatochromic mechanism for the membrane potential-sensitive dye rather than the electrochromic mechanism.
Osakai
Toshiyuki
T
Department of Chemistry, Graduate School of Science, Kobe University, Nada, Kobe, 657-8501, Japan. osakai@kobe-u.ac.jp
Sawada
Junpei
J
Nagatani
Hirohisa
H
D005025:Ethylene Dichlorides / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D008564:Membrane Potentials; D010713:Phosphatidylcholines / Q000737:chemistry; D011726:Pyridinium Compounds / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
D005025:Ethylene Dichlorides; D005456:Fluorescent Dyes; D010713:Phosphatidylcholines; D011726:Pyridinium Compounds; D014867:Water; C015153:1,2-dilauroylphosphatidylcholine; C024565:ethylene dichloride; C050019:1-(3-sulfonatopropyl)-4-(beta)(2-(di-n-butylamino)-6-naphthylvinyl)pyridinium betaine