Recyclable amyloid-based magnetic nanonets for active capture and removal of nanoplastics from water

Nanoplastics (NPs), as persistent and unregulated aquatic contaminants, evade conventional removal technologies, posing severe health risks and urgently demanding innovative, effective solutions. Here we introduce recyclable magnetic biohybrid nanonets (LAF-IONPs), engineered through in situ growth of iron oxide nanoparticles (IONPs) on lysozyme amyloid fibrils (LAFs). Stabilized by synergistic interfacial interactions, LAF-IONPs efficiently capture NPs over a wide range of sizes (30–1,000 nm) and chemical compositions across environmentally relevant concentrations and conditions (pH 7–9, high salinity and co-existing pollutants). The superior removal efficiency arises from magnetic active motion and abundant fibril binding sites. Remarkably, LAF-IONPs achieved 98.0–99.9% NPs removal from various real water samples and maintained >95% efficiency over 100 recycling cycles when using a custom alternating magnetic field system. Critically, LAF-IONPs treatment reduced in vivo NPs bioaccumulation by 91.5%. This work establishes a blueprint for designing recyclable biohybrid adsorbents for active, efficient and sustainable removal of NPs and potentially other emerging contaminants. Nanoplastics are persistent water contaminants that evade conventional removal methods. Magnetic biohybrid nanonets are found to capture up to 99.9% of them, remain highly recyclable and greatly reduce in vivo accumulation.