Tuning chromatic response, sensitivity, and specificity of polydiacetylene-based sensors
Polydiacetylenes (PDAs) are a class of conjugated polymers with unique optical properties that make them excellent materials for the construction of colorimetric sensors. Self-assembly of amphiphilic diacetylene monomers in solution and photopolymerization of neighboring diacetylene groups yield blue-phase PDAs. PDAs can be functionalized with a wide range of recognition elements, and chemical and biological recognition events, e.g. protein-antibody interaction, nucleic acid hybridization, pH change, can generate a visible blue-to-red chromatic transition of PDA. The color change mechanism remains to be fully elucidated and is analyte dependent, and its understanding is key to optimizing PDA-based sensing systems. In this review, we provide an overview of different methods of tuning the chromatic response, sensitivity, and specificity of PDA-based sensors. It draws conclusions regarding the relationship between these variables, specifically sensitivity and specificity, to guide the future development of PDA sensing systems.