| Abstract
| - Photophysical properties of 3-acetyl-4-oxo-6,7-dihydro-12H-indolo[2,3-a]quinolizine (AODIQ), a bioactivemolecule, has been investigated in well-characterized, monodispersed biomimicking nanocavities formed bysodium bis(2-ethylhexyl)sulfosuccinate (AOT) in heptane using steady-state and picosecond time resolvedfluorescence and fluorescence anisotropy. The emission behavior of AODIQ is very much dependent uponthe water/surfactant mole ratio (W), i.e., on the water pool size of the reverse micellar core. AODIQ exhibitsa sharp decrease in fluorescence anisotropy with increasing W, implying that the overall motional restrictionexperienced by the molecule is decreased with increased hydration. Some of the depth-dependent relevantfluorescence parameters, namely, fluorescence maxima and fluorescence anisotropy (r), have been monitoredfor exploiting the distribution and microenvironment around the probe in the reverse micelles. Fluorescencespectral position and fluorescence quenching studies suggest that the probe does not penetrate into the reversemicellar core; rather it binds at the interfacial region. Quantitaive estimates of the micropolarity andmicroviscosity at the binding sites of the probe molecule have been determined as a function of W.
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