A study on the preparation of alkyne functional nanoparticles via RAFT emulsion polymerisation

The multivalent presentation of functional groups on nanoparticle surfaces has long been exploited to attach biologically active moieties. The conventional chemistries typically used (amide, ester, disulfide) however, are non-selective and inefficient. The Huisgen azide alkyne [1,4] cycloaddition (CuAAC) 'click' reaction has paved the way for atom economic, and orthogonal conjugation chemistries, and is now widely used in nanoparticle science. In this work, alkyne functionalised nanoparticles were prepared, without lengthy post-nanoparticle synthesis modification procedures, exploiting RAFT emulsion polymerisations stabilised by functional macro-RAFT agents. Our results indicated that ester derived RAFT agents and addition of pendant charged groups are vital to retain colloidal stability and narrow molecular weight distributions. Finally the nanoparticles and model polymers were functionalised with an azido functional polymer and fluorescent dye, showing the surfaces were easily accessible for rapid and efficient post-polymerisation functionalisation.