The interfacial environment of AOT based reverse micelle (RM), which has similarity with bio-membranes, has been probed by measuring: (1) magnetic field effect (MFE) on Pyrene-DMA exciplex luminescence; (2) wavelength-dependence of the exciplex lifetime. At least two different types of exciplexes have been identified at different locations within the RM interface. Among these, only the red edge component of the emission centered at similar to500 nm (Ex(500)) is field-sensitive. It makes sense to presume that the Ex(500) is localized at the mobile zone of the interface while the other field-insensitive one, centered at similar to430 nm (Ex(430)) resides at the immobile zone of the interface. Time resolutions of luminescence at different wavelengths indicate that the field-sensitive exciplex is formed at the expense of Ex(430). (C) 2005 Elsevier B.V. All rights reserved.