New fluorescent probes applicable to aggregates of fluorocarbon surfactants.

ABSTRACT

We developed new benzofurazan (NBD) labeled probes for fluorocarbon surfactant systems. The fluorescence behavior depended on the solubilization site of the fluorescent probes in the surfactant aggregates. The NBD-labeled probes suffered virtually complete reduction in the presence of Na(2)S(2)O(4) owing to the solubilization at the surface of 2-hydroxy-1,1,2,3,3-pentahydroperfluoroundecyldiethylammonium bromide (FC(8)DAB) aggregates. On the other hand, N-(3-sulfopropyl)acridinium (SPA) in FC(8)DAB aggregates showed residual fluorescence in spite of NaBH(4) addition. The large vesicles of FC(8)DAB were confirmed by DLS measurements. These facts suggest that SPA is solubilized in an inner water phase of the vesicles. The NBD labeled fluorescence probe is quite effective for the study of the aggregation behavior of fluorocarbon surfactants.