  We demonstrate an emulsion-polymerisation technique to embed
dibenzoterrylene-doped anthracene nanocrystals in polymethyl methacrylate
(PMMA) nanocapsules. The nanocapsules require no further protection after
fabrication and are resistant to sublimation compared to unprotected
anthracene. The room temperature emission from single dibenzoterrylene
molecules is stable and when cooled to cryogenic temperatures we see no change
in their excellent optical properties compared to existing growth methods.
These now robust nanocapsules have potential for surface functionalisation and
integration into nanophotonic devices, where the materials used are compatible
with incorporation in polymer-based designs.
