Self-reporting and refoldable profluorescent single-chain nanoparticles.

We pioneer the formation of self-reporting and refoldable profluorescent single-chain nanoparticles (SCNPs) the light-induced reaction ( = 320 nm) of nitroxide radicals with a photo-active crosslinker. Whereas the tethered nitroxide moiety in these polymers fully quenches the luminescence ( fluorescence) of the aromatic backbone, nitroxide trapping of a transient C-radical leads to the corresponding closed shell alkoxyamine thereby restoring luminescence of the folded SCNP. Hence, the polymer in the folded state is capable of emitting light, while in the non-folded state the luminescence is silenced.

Stepwise Unfolding of Single-Chain Nanoparticles by Chemically Triggered Gates.

The orthogonal, stepwise, and order-independent unfolding of single-chain nanoparticles (SCNPs) is introduced as a key step towards actively controlling the folding dynamics of SCNPs. The SCNPs are compacted by multiple hydrogen bonds and host-guest interactions. Well-defined diblock (AB) and tetrablock (ABCD) copolymers are equipped with orthogonal recognition motifs via modular ligation along the lateral chain.