Detection of sulfate surface-active substances via fluorescent response using new amphiphilic thiacalix[4]arenes bearing cationic headgroups with Eosin Y dye

Abstract

© 2016 Elsevier B.V.New ammonium-containing derivatives of p-tert-butylthiacalix[4]arene in 1,3-alternate stereoisomeric form were synthesized via copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction of corresponding azides with N-propargyl-N,N,N-triethylammonium bromide. Critical aggregation concentration (CAC) of new amphiphilic thiacalixarenes 1-3 (with butyl, octyl and tetradecyl substituents) determined by pyrene micellization method are 91, 59 and 33 μM, respectively. According to DLS data the diameter of these aggregates is around 130 nm. Anionic dye Eosin Y (EY) forms the associates with positive charged thiacalixarenes 1-3, shifts CAC to the low concentration region (2 μM) and decreases nanoaggregates size up to 90 nm. Thiacalixarene/EY associates were investigated as fluorescent probe for the determination of different surface active substances (SAS) in the solution. It was found that only sodium dodecyl sulfate (SDS) and sodium laureth sulfate (SLES) causes EY release, while other anionic, cationic and zwitterionic SAS form only mixed aggregates. Fluorescent response of thiacalixarene/EY associates is considerable from 3.5 μM concentration of SDS