Synthesis of a multifunctional poly(p-phenylene ethynylene) scaffold with clickable azide-containing side chains for (bio)sensor applications

Poly(p-phenylene ethynylene) (PPE) copolymers with alternating alkoxy and azide-functionalized alkoxy side chains were efficiently synthesized via Sonogashira polymerization and the materials were fully characterized. Among the different synthetic protocols investigated, the best results were obtained when employing a pre-polymerization functionalization approach and upon implementing the azide-functionalized side chains on the diiodophenyl building block. End-capping of the conjugated polymer chains is shown to be essential for preventing side reactions. As a proof of principle, phenylacetylene is clicked in a nearly quantitative way on the polymer backbone. Furthermore, successful click-immobilization of randomly alkynylated protein A onto an azide-functionalized PPE film illustrates the potential use of these materials in a variety of (bio)sensor applications.