Fluorescence and Light Scattering Studies on Indole-3-Acetic Acid in Micellar Media

Indole-3-Acetic Acid (I-3-AA) is a phytochrome auxin found in tulip bulbs, in unripe pea seeds, in fungi and in rice cells. It is a plant growth hormone and is biologically and analytically an important molecule. Even small traces of I-3-AA can be assayed by using fluorimetric method. The enhanced fluorescence emission intensity as well as quantum yield values in microheterogeneous micellar environment prove that the suspending hydrophobic I-3-AA molecules are solubilized. The solubilizing action of surfactants on I-3-AA has been supplemented by light scattering studies and some theoretically calculated spectral parameters like empirical fluorescence coefficient (k_f), fluorescence quantum yield (σ_f), molar extinction coefficient (ε) and Stokes' shift values.