Nanoscale PDA disassembly in ionic liquids: structure-property relationships underpinning redox tuning.
Nanoscale disassembly of mussel-inspired polydopamine (PDA) in ionicliquids (ILs) was recently shown to induce an electron paramagnetic resonance (EPR)-detectable reorganization of free radical centers in the resulting nanoparticles (NPs) in an IL-controlled manner. Herein, we report electrical impedance spectroscopy (EIS) data showing that PDA NPs produced by suspending samples obtained in Tris and bicarbonate buffer (PDA-T and PDA-C) in a series of different ILs, display different redox activity as a result of structural control combined with surface-IL interactions. A remarkable correlation was found between spin density and susceptibility to oxidation,in a manner that was finely tuned by interaction of PDA with the ion pairs in IL. The observed structural control over free radical properties and redox behavior of PDA NPs in ILs opens novel perspectives for the rational design of functional nanovectors of possible interest for drug delivery and theranostic applications.