Colorimetric Transition of Polydiacetylene/Cyclodextrin Supramolecular Assemblies and Implications as Colorimetric Sensors for Food Phenolic Antioxidants

Molecular self-assembly has significant potential in the field of sensing. Polydiacetylenes (PDAs) are conjugated polymers possessing peculiar optical properties obtained by photopolymerization self-assembled diacetylene monomers. Herein, blue-to-red phase transition upon either thermal stimulus or interaction with cyclodextrins (CDs) two PDAs, bearing carboxylic (PCDA) amino (PCDA-NH2) polar heads, is investigated to develop a colorimetric sensor for food phenolic antioxidants. The change PDA head does not affect significantly thermo-chromatic transition. Upon stimulus, both color occurs straightforward between distinct stable states and involve disordering crystal phase, as revealed UV–vis spectroscopy SAXS analysis. Contrarily, PDA/α-CD influenced intermolecular forces among heads more efficient PCDA. α-CDs presumably cause changes backbone conformation local environment surrounding individual chains. PCDA/α-CD assemblies sensors detection Tyrosol (Ty) caffeic acid (CAF), using principle competitive inclusion complex formation. system results be sensitive CAF than Ty may permit determination concentration ranges suitable different products.