Novel Fluorescence Spectral Deconvolution Method for Determination of Critical Micelle Concentrations Using the Fluorescence Probe PRODAN

A simple yet novel method for the determination of critical micelle concentrations is introduced. In this method, the fluorescence spectrum of a probe molecule is deconvoluted into constituent spectra consisting of that from the surfactant free probe and that from the micelle-bound probe molecule. There is no assignment of arbitrary shape functions to the spectra in this process. Using the probe molecule PRODAN, the deconvolution method is compared with the more traditional fluorescence spectral maximum shift method for the cmc determination of aqueous surfactants including sodium dodecyl sulfate (SDS), Brij 35, and reverse micelles of Triton X-100 (TX-100) in cyclohexane/hexanol solution. Finally, to help determine its position in the micellar environment, fluorescence quenching experiments were performed on PRODAN in aqueous SDS and TX-100 reverse micelle solutions.