Programmable Energy Dissipation in a DNA-pNIPAM Hybrid Hydrogel for Ultrastable Actuation-Enhanced Biosensing of...

DNA-based hydrogels are attractive for biosensing due to their molecular recognition and programmability, yet their practical use is severely limited by poor mechanical robustness and rapid fatigue under repeated actuation. Here, we overcome these barriers through a programmable energy dissipation mechanism in a DNA-hybrid hydrogel. Self-complementary DNA duplexes serve as reversible sacrificial bonds within a covalent poly(N-isopropylacrylamide) (pNIPAM) network, with their melting temperature precisely matched to the polymer's lower critical solution temperature. This design channels mechanical stress into reversible DNA dissociation rather than permanent network damage, conferring improved fatigue resistance: 100% volumetric recovery over 90 actuation cycles. Leveraging this stable platform, we construct an actuation-enhanced biosensor for acetamiprid. The hydrogel's rhythmic volume change actively pumps target molecules into the sensing domain while performing in-gel self-cleaning to remove unbound interferents. The sensor achieves a detection limit of 0.083 nM and reliable performance in complex food and environmental matrices with minimal pretreatment, matching the accuracy of chromatography-based methods. This programmable energy dissipation strategy provides a general route to robust, high-performance biosensors, with broad applicability in analytical chemistry and environmental monitoring.