A new strategy for the ratiometric fluorescence detection of Zn(II) in the surfactant solution

A new strategy derived from the intramolecular charge transfer mechanism was employed to create a ratiometric sensing system for Zn²⁺ in aqueous solution by using sodium dodecyl sulfate (SDS) micelles as the scaffold. The amphiphilic carboxamidoquinoline-based sensor (AQZ2Cl) was simultaneously solubilized at different locations in the SDS micelle. Some AQZ2Cl molecules were adsorbed at the micelle-water interface and emitted a fluorescence- enhancing and red-shifted signal upon binding Zn²⁺. And the others were incorporated into the palisade layer of the micelle, in which the produced bands had no appreciable changes with the addition of Zn²⁺, thus acting as an internal standard and allowing AQZ2Cl as a ratiometric sensor for the detection of Zn²⁺.