Colorimetric and fluorometric ammonia sensor based on protonated bipyridyl-containing polydiacetylene

Abstract

Chemical sensors based on stimulus-responsive chromogenic materials have found great importance due to their strong capability of manipulating optical properties and vivid color display. In this work, chromogenic polydiacetylene (PDA) is generated by the polymerization of protonated supramolecular assemblies of bipyridyl-containing diacetylene precursor (bpy-PCDA-H+). A blue-colored polymeric PDA of bpy-PCDA-H+ was obtained by UV irradiation of monomeric assembles. Since supramolecular architecture is preorganized through protonation-induced interactions of molecular blocks, bpy-PCPDA-H+ generated intriguing assembly-related sensory response via deprotonation mechanism, producing distinctive blue to red chromatic transition and fluorescence turn-on response against ammonia. The self-assembly behavior, topochemical polymerization, and ammonia sensing properties of bpy-PCPDA-H+ were investigated using spectroscopic methods.