Synthesis, characterization and electropolymerization of functionalized organic salt − anilinium saccharinate and electrochemically controlled release of saccharinate anions

In this work, a novel functionalized organic salt − anilinium saccharinate ([HANI][Sac]) was synthesized by the ion exchange method, and its composition and properties were characterized by 1H NMR, 13C NMR, ESI/MS and TG-DSC techniques. [HANI][Sac] can be used as both monomer and supporting electrolyte for efficient electrosynthesis of polyaniline (PANI) in acetonitrile. The obtained PANI has hierarchical porous structure and its doping degree with saccharinate anion ([Sac]-) is as high as 33.5%. The resulting [Sac]--doped-PANI (PANI-[Sac]) can be used as an electrochemically controlled drug delivery system. The in vitro release kinetics of [Sac]- under different potential stimuli conditions showed that, at a given time, the release rate of [Sac]- and its release percentage (ratio of the amount released to that loaded) increase with the negative shift of the applied potential. The amount of [Sac]- loaded and/or released can also be regulated by varying the charge for PANI electropolymerization. The present work provides a new strategy for the facile construction of conducting polymer-based electrochemically controlled drug release system.