pH-Controlled Off-On-Off Switch Based on Cu2+-Mediated Pyrene Fluorescence in a PAA-SDS Micelle Aggregated Supramolecular System

We report herein the fluorescence response of pyrene in the presence of sodium dodecyl sulfate (SDS) micelle and poly(acrylic acid) (PAA) with Cu2+ as an ionic quencher. Pyrene present in the PAA-SDS complex is quenched by Cu2+ at pH similar to 2 (off state). Quenched pyrene emission is recovered at pH similar to 8 (on state). Due to easy protonation and deprotonation of the PAA chain in aqueous solution, this pH-controlled micellar ternary system exhibits a highly reversible off-on-off switch of the pyrene emission.