Reactive oxygen species/glutathione dual responsive nanocarrier co‐delivers pesticide and chitosan oligosaccharide for enhanced control of crop disease

BACKGROUND: Conventional pesticide formulations are often limited by poor targeting efficiency and low utilization rates, resulting in excessive application and severe environmental pollution. To overcome these drawbacks, smart stimuli-responsive delivery systems based on nanotechnology have become a forefront research area in agrochemicals. Of particular interest are systems capable of responding to specific biochemical stimuli at the site of infection. RESULTS: In this study, we developed a dual-responsive system, methoxy polyethylene glycol (mPEG)-dithiobisethanol (SS)-thioketal (TK)-chitosan oligosaccharide (COS), designed for the targeted release of pesticides and the integrated delivery of plant immunity inducers, COS. The system utilizes reactive oxygen species and glutathione to cleave TK and SS bonds, thereby triggering the release of both pesticide and COS. Structural characterization confirmed the formation of spherical nanoparticles with an average diameter of 300 nm. Biological evaluations demonstrated that the system effectively enhanced disease control through targeted payload delivery and specific activation of the salicylic acid signaling pathway. This chemico-immunological synergy achieved a control efficiency of 74.28%, representing a 147.60% improvement compared to validamycin alone. The synergistic effect was supported by a reduction in lesion area on detached leaves. DISCUSSION: This work presents an effective strategy for crop disease management by combining prompt and targeted pesticide release with induced plant immunity. The dual-responsive system enhances pesticide efficiency through precise and timely release, while simultaneously mitigating environmental risks. This approach represents a promising and sustainable solution for modern pest management in agriculture. © 2026 Society of Chemical Industry.