Structure and dynamics of micelle-based fluorescent sensor for transition metals

A structural model of the fluorescent supramolecular sensor Triton X-100:pyrene:dodecyl-dioxo-2,3,2 is proposed, based on a micellar approach. Under the experimental conditions, phase behavior of the micellar solution restricts ligand:surfactant ratio to 1:10. Thermodynamic and kinetic data indicate that the quenching mechanism involved in the ON–OFF response is intramicellar, and selective compartmentalization of fluorophore and quencher inside micelles can affect effective collisions. An oblate ellipsoid is proposed as the most suitable structure for this micellar-based sensor. Main structural properties of surfactant aggregates and the complex itself are not affected by this assembling, suggesting that the micelle acts as a dynamic substrate.