Programmed Interfacial Phase Separation for Spatiotemporal Fungicide Delivery via Tunable Micro/Nano Architectures

Translating dynamic liquid-liquid phase separation into robust solid-state architectures remains a challenge in materials engineering. Here, we report a composition-driven interfacial assembly strategy that couples supramolecular coacervation with metal-phenolic coordination to engineer tunable fungicide carriers. By modulating the mass ratio between tea polyphenols (TP) and non-ionic surfactants, we generate fluid templates that are kinetically trapped via pH-triggered iron complexation. This one-pot protocol allows for the precise regulation of the micro-to-nano population ratio, effectively addressing the dimensional mismatch between soil retention and systemic uptake. The resulting architecture achieves a functional division: microcapsules function as stationary reservoirs for rhizosphere protection, while nanocapsules act as mobile vectors for systemic curative action. Furthermore, the metal-phenolic shell exhibits pathogen-responsive disassembly upon exposure to fungal virulence factors, including oxalic acid and cellulases secreted by Fusarium pathogens. Validated in a peanut root rot model, this system demonstrates improved spatiotemporal efficacy and reduced aquatic toxicity toward zebrafish compared to commercial formulations. Consequently, this work presents a versatile methodology for structuring dynamic liquid interfaces based on TP-surfactant supramolecular interactions, offering a potent solution for precision agriculture through the controlled solidification of supramolecular assemblies.