Dual-Engineered Cellulosic Triboelectric Platforms with Ultrasensitive Alkaline Responsiveness for Real-Time Seafood Freshness Monitoring.

Achieving a synergy between structural stability and an ultrasensitive response to alkaline gases remains a key challenge in developing advanced gas-sensitive cellulosic triboelectric materials. Unlike conventional approaches relying on simple physical blending, this work introduces a novel coupling strategy combining in situ growth with defect engineering. The oxygen-containing groups on the cellulose skeleton coordinate with Zn, serving as nucleation sites for the in situ growth of zinc oxide (ZnO) nanoparticles, while acid vapor etching precisely creates defective regions. Theoretical calculations demonstrate that defective ZnO exhibits a 55.5% higher NH adsorption capacity than pristine ZnO. The resulting AZP-TENG achieves an exceptional detection limit of 5 ppm. Remarkably, even after 60 min of continuous rubbing under 30 N force, the ZnO nanoparticles remain firmly anchored to the fiber surfaces without significant detachment. Moreover, the output signal evolution of the triboelectric nanogenerator (TENG) in packaged microenvironments shows a strong correlation with the total volatile base nitrogen (TVB-N) levels in scallops during storage, highlighting its potential for real-time seafood freshness monitoring. This study provides a reliable and innovative strategy for designing ultrasensitive gas-sensitive cellulosic triboelectric materials, paving the way for self-powered, low-cost, and highly sensitive electronics in food safety applications.