Synthesis of Alkyne-Terminated PCDA Linker for Applying Click Chemistry on PDA Layers

An alkyne-terminated PCDA (10,12-pentacosadiynoic acid) linker, which can undergo a simple click reaction with azide compounds, was synthesized for the purpose of immobilizing various kinds of biomolecular surface ligands on PDA (polydiacetylene) layers. In order to confirm the ability of the linker compound to anchor azide-modified surface ligands, we carried out a model ­reaction with benzyl azide under typical click-reaction conditions. We were able to confirm that the model reaction proceeded smoothly by observing the color change of PDA, including its thermochromic reversibility.