Noninvasive probing of aqueous Triton X-100 with steady-state and frequency-domain fluorometry

Most fluorescence spectroscopic methods that investigate the properties of surfactant-based systems are invasive in nature as they rely on information afforded by an externally-introduced probe. External probes may adversely affect the colloidal property of interest. Information from chromophoric surfactants as endogenous probes of micellization process is presented. Fluorescence from phenyl moiety of a common nonionic surfactant Triton X-100 in water is demonstrated to be rich in information on surfactant aggregation. While Triton X-100 concentration-dependent fluorescence emission and excitation can be effectively used to monitor the presence of micelles, frequency-domain excited-state fluorescence intensity decay data affords key dynamic parameters characterizing Triton X-100 micelles.