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

Abstract

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. † Electronic supplementary information (ESI) available: MALDI-TOF mass spectrum of copolymer P2a, 1 H and 13 C NMR spectra of monomers and polymers, cyclic voltammograms, and FT-IR spectra. See

Effect of Branching on the Optical Properties of Poly(p-phenylene ethynylene) Conjugated Polymer Nanoparticles for Bioimaging

“…The required monomers 1 and 2 were synthesized according to previously published protocols. 50 The pristine PPE polymers were then obtained by Sonogashira polymerizations. The polymerization conditions were based on a reported (solution) procedure, 42 but the amounts of the monomers were adjusted according to the amount of branching molecule added (3/5%).…”

“…The required monomers (1 and 2) were prepared according to literature procedures. 50 PPE-lin was synthesized according to a reported procedure. 45 An orange PPE polymer was obtained (0.076 g, 82%).…”

“…Moreover, the pending (solubilizing) side chains enable introduction of specific (e.g., click) functionalities, which can be interesting in terms of specific cell targeting. 42,50 So far, only a few studies have been devoted to PPE-type NPs. Liu et al prepared particles from amphiphilic PPEs via self-assembly, 51 while other reports deal with the influence of side chain modifications on cytotoxicity, subcellular localization and optical properties.…”

“…Poly­( p -phenylene ethynylene)­s (PPEs) were selected as the CP materials of choice because of their simple but rigid backbone structure, which leads to a relatively high PLQY, large molar extinction coefficient and high photostability. ,, By the introduction of acceptor moieties in the PPE backbone, the bandgap can eventually be lowered and the emission can be pushed into the NIR region. Moreover, the pending (solubilizing) side chains enable introduction of specific (e.g., click) functionalities, which can be interesting in terms of specific cell targeting. , So far, only a few studies have been devoted to PPE-type NPs. Liu et al prepared particles from amphiphilic PPEs via self-assembly, while other reports deal with the influence of side chain modifications on cytotoxicity, subcellular localization and optical properties. ,, Ponzio et al introduced a cross-linked nonconjugated matrix material to yield high-strength rigid particles which can withstand dissolution by organic solvents.…”

A New Series of Conjugated Platinum‐co‐Poly(p‐phenylenebutadiynylene)s Polymers: Syntheses and Photophysical Properties

“…Because of novel electronic properties, conjugated poly( p ‐phenyleneethynylene)s (PPEs) are important materials for optoelectronic devices—light‐emitting diodes (LEDs), photovoltaic cells, and chemical and biological sensors. The inclusion of transition metals in the main chain of the PPEs gives M–C σ‐bonded rigid‐rod conjugated polymeric system, which is air and thermally stable, solution processable, and these materials possess useful optoelectronic properties.…”