Photodegradable and size-tunable single-chain nanoparticles prepared from a single main-chain coumarin-containing polymer precursor.

A polyester bearing coumarin moieties in the main chain was used to prepare photodegradable single-chain nanoparticles (SCNPs) of variable sizes. While the intra-chain photodimerization of the chromophore determines the size of SCNPs, the photocleavage occurring under UV irradiation at a different wavelength breaks down the ultra-small nanoparticles.