Time-resolved total-internal-reflection fluorescence study on molecular interactions at liquid/liquid interfaces

Abstract

Molecular interactions proceeding at a water/CCl4 interface were investigated directly by means of time-resolved total-internal-reflection (TIR) fluorescence spectroscopy. The TIR fluorescence decay profiles and fluorescence dynamic anisotropy decays of Riboflavin (RF) in the presence or absence of a N,N-dioctadecyl-[1,3,5]triazine-2,4,6-triamine (DTT) as a guest in the CCl 4 phase indicated that molecular recognition mediated by complementary triple hydrogen bonding took place effectively at the water/CCl4 interface. Furthermore, the photoreaction mechanisms of the RF-DTT hydrogen-bonded complex that proceeded at the water/CCl4 interface were considered based on results observed by steady state and dynamic fluorescence measurements of the RF-DTT complex under the TIR conditions. Hybridization of complementary single-stranded DNAs at a water/CCl4 interface was also studied by the fluorescence dynamics of ethidium bromide as a probe for the DNA structure. The structures of double-stranded DNA at the interface were analyzed. © 2005 The Japan Society for Analytical Chemistry.