A smart selenium-based nanopesticide for targeted fungicide delivery: Triple-action antifungal mechanism and sustainable management of Fusarium wilt in peanut

Fusarium wilt, caused by Fusarium oxysporum ( F. oxysporum ), poses a significant threat to global crop production. Conventional fungicides such as carbendazim (CBZ) encounter substantial challenges, including single-target resistance, poor environmental stability, an effective utilization rate of less than 0.1 %, and biosafety concerns. To overcome these limitations and address the core bottlenecks of existing nanopesticides, we developed a novel intelligent nanopesticide (CBZ@Se-CS, CSC) through a straightforward non-covalent self-assembly of chitosan and selenium nanoparticles for targeted delivery of CBZ. CSC has an average particle size of approximately 129 nm and a zeta potential of + 43.1 mV. It exhibited an 85 % cumulative release rate in the acidic microenvironment (pH 5.0) that simulates fungal infection sites.In vitro antifungal assays demonstrated that CSC achieved an EC₅₀ of 0.139 mg/L, showing 4.35-fold higher efficacy compared to free CBZ. Its triple-target synergistic mechanism potentially disrupts fungal cell membranes, induces oxidative stress and inhibits virulence factor synthesis, which may help mitigate resistance risks. Furthermore, CSC exhibits bidirectional vascular translocation in plants, host defense priming capacity, robust environmental stability and minimal toxicity to non-target organisms. It also promotes peanut seed germination. Enabled by green and potentially scalable preparation, CSC may reduce chemical inputs while providing a practical solution for managing vascular-colonizing pathogens such as F. oxysporum . This work aligns with the UN Sustainable Development Goals for food security and sustainable agriculture, presenting an innovative paradigm for the design of eco-friendly smart nanopesticides.