Polystyrene nanoparticles doped with a luminescent europium complex

► Polymer nanoparticles can be doped during miniemulsion polymerization. ► PS particles can be doped with Eu(tta)3phen at levels up to 2% by weight. ► Luminescence of the complex is unchanged by the polymer matrix. ► No self-quenching is found despite relatively high local Eu3+ concentrations.