A Solarization-Triggered Fungicide Controlled-Release Platform Enabled by “Carrier-in-Carrier” Hiberarchy for On-Demand Soil-Borne Disease Defense

Soil application of fungicides is a primary control strategy for soil-borne diseases, while soil solarization provides an economical and eco-friendly supplementary approach. Herein, we propose a novel "carrier-in-carrier" photothermal-responsive delivery system (ANTs) to integrate soil solarization with on-demand fungicide release for sustainable management of soil-borne diseases. The fungicide azoxystrobin (AZOX) was first loaded into inner Cu-PDA nanobottles (Cu-PDA NBs), which were further embedded in situ within an outer lauric acid (LA)-EtOH-H 2 O ternary eutectic phase-change matrix (TPS) via a solvent exchange-driven phase change strategy. The resulting ANTs exhibit superior photothermal-controlled release performance. Under solarization, the high photothermal conversion efficiency of Cu-PDA NBs rapidly triggers the solid-to-liquid phase transition of TPS (∼39°C), enabling sequential AZOX release from TPS and Cu-PDA NBs. This design synchronizes fungicide release with solarization-enhanced soil disinfection while balancing initial burst release with long-term sustained delivery. In the absence of solarization, solidified TPS confines vertical AZOX migration, reducing soil leaching by 8% compared to commercial SC formulations, thereby maintaining effective fungicidal concentrations and mitigating groundwater contamination risks. Using Verticillium dahlia (strain V991) as a model pathogen, ANTs demonstrate a 30% lower median effective concentration (EC 50 =0.900 mg/L) than commercial formulations, attributed to synergistic antifungal effects of LA and Cu-PDA NBs. In vivo cotton trials confirm 20% higher control efficacy of ANTs against Verticillium wilt under solarization than commercial formulations. The hierarchical carrier structure endows ANTs with minimal phytotoxicity to cotton germination, high biological safety to earthworms, and reduced impacts on dominant soil microorganisms. This work pioneers a solarization-compatible pesticide delivery platform bridging advanced material design with field-applicable disease control strategies. • Novel "carrier-in-carrier" system integrates solarization with fungicide release. • Photothermal-controlled release improves fungicide efficacy and reduces leaching. • Antifungal efficacy enhanced by synergistic effects of Cu-PDA NBs and lauric acid. • Sustainable, eco-friendly delivery with minimal toxicity to non-target organisms. • In vivo trials show 20% higher control efficacy of ANTs against Verticillium wilt.