Polydiacetylene Materials Beyond Sensing with Emerging Applications in Biomedical, Catalysis, Optics, and Energy

Polydiacetylenes (PDAs) are well known for their ene-yne backbone and its unique color changing property from blue to red. The color changing property has made them attractive for chemo sensing, bio sensing, and other various sensing application. However, viewing PDAs solely as passive colorimetric sensors overlooks their broader functional potential. This article focuses on the growing list of "beyond sensing" applications in which PDAs serve a an active, functional role. The increasing application in biomedical technologies, covering smart drug-delivery systems, photothermal and photodynamic therapy, and tissue-engineering scaffolds has been addressed. PDAs potential in catalysis, such as photocatalytic pollutant degradation and greener synthetic methods, is also discussed. In addition to photocatalytic activity and healthcare application, PDAs showed capabilities in advanced optical, electronic, and photonic materials, ranging from nonlinear optical components to circularly polarized light emitters. This article is focused on redefining PDAs as versatile materials, emphasizing design strategies, structure-property correlations and essential mechanisms to handle issues in healthcare, environmental sustainability, and materials science, rather than merely as sensors.