Polydiacetylene-Based Sensing Technologies

Polydiacetylenes are a class of conjugated polymers featuring alternating carbon–carbon triple and double bonds along their backbone. Their unique chromic behaviour—most notably a rapid colour change from blue to red—and accompanying fluorescence modulation upon exposure to mechanical, thermal, chemical or biological stimuli have positioned them at the forefront of responsive sensor development. Fabricated by topochemical polymerisation of amphiphilic diacetylene monomers, PDA materials can be assembled into films, vesicles, fibres, single particles and composite matrices. The chromic transition is driven by conformational alterations in the π-conjugated backbone, enabling quantifiable optical readouts of environmental changes. Advances in molecular functionalisation, co-assembly with metal ions, and microfabrication have broadened application domains to include mechanical stress mapping in microfluidic systems, visual friction-force imaging, pathogen and toxin detection, and food safety monitoring. Such versatility, combined with low-cost production and equipment-free operation, underscores the global significance of PDA-based sensing platforms in fields ranging from biomedical diagnostics to structural health management.

Research from Nature Portfolio

Recent studies have exploited the mechanofluorescent response of single-particle PDA sensors generated via co-flow microfluidics, enabling real-time tracking of fluid-induced stresses within biomimetic capillaries. These particles exhibit nonlinear fluorescence transitions attributed to torsional energy changes along the PDA backbone, facilitating quantitative assessments of viscosity and nanoparticle interactions. In parallel, a retro Diels–Alder reaction-driven self-assembly strategy has yielded diacetylene-functionalised supramolecular polymers with in situ release of reactive maleimide and furan groups, resulting in colourimetric sensors tunable through photochemical and thermal triggers. Together, these contributions demonstrate the synergy of polymer chemistry and microfabrication in enhancing PDA sensor sensitivity and functional diversity.

Research from all publishers

Engineering efforts beyond the portfolio have delivered PDA-coated composite devices for high-sensitivity, spatiotemporal mapping of compression stresses, utilising time-evolutional diffusion of guest polymers to visualise and quantify kPa-level loads through chromic shifts. Similarly, cascading stimuli responsiveness in friction-imaging devices has been realised by integrating PDA with dry liquid droplets, enabling colourimetric imaging of weak friction forces and detailed mapping of handwriting pressure. In the optical domain, diacetylene-functionalised cyanostilbene luminogens have been crafted to achieve multi-state photochemical and thermally programmable optical responses in a single molecule, opening avenues for switchable patterns and secret codes. Furthermore, the deployment of PDA-based films, hydrogels and substrate-bound aptasensors in food packaging has proven effective for colourimetric detection of spoilage markers, pathogens and heavy metals, highlighting the practicality of PDA platforms in resource-limited settings.

Polydiacetylene-Based Sensing Technologies publication trend

The graph below shows the total number of articles in polydiacetylene-based sensing technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Polydiacetylene (PDA): Conjugated polymer formed by topochemical polymerisation of diacetylene monomers, exhibiting chromic and fluorescent transitions.

Topochemical polymerisation: Solid-state polymerisation of aligned monomeric crystals under irradiation to produce extended conjugated backbones.

Mechanofluorescence: Fluorescence emission induced or modulated by mechanical forces, used to map stress distributions.

Retro Diels–Alder reaction: Reversible cycloaddition reaction cleaving bridged bicyclic adducts to generate reactive monomers for triggered assembly.

Chromism: Reversible change in the optical properties of a material, typically manifesting as a colour shift under external stimuli.

References

1. A single-particle mechanofluorescent sensor. Nature Communications (2024).
2. Self-assembly using a retro Diels-Alder reaction. Nature Communications (2021).
3. High‐Sensitive Spatiotemporal Distribution Imaging of Compression Stresses Based on Time‐Evolutional Responsiveness. Small (2024).
4. A highly sensitive friction-imaging device based on cascading stimuli responsiveness. Materials Horizons (2023).
5. Photochemically and Thermally Programmed Optical Multi‐States from a Single Diacetylene‐Functionalized Cyanostilbene Luminogen. Advanced Science (2024).
6. Polydiacetylene-based sensors for food applications. Materials Advances (2022).