Breaking the selectivity barrier in Fenton process: Aptamer-empowered nano-Fenton system for targeted destruction of...

The non-selective generation of hydroxyl radicals (·OH) in classical Fenton systems severely limits their precision in targeting trace-level emerging contaminants (ECs) for degradation. This study addresses this challenge by integrating molecular recognition with nanoconfined catalysis, designing an aptamer-functionalized superparamagnetic catalyst Apt-Au/Fe₃O₄ for the precise removal of high-risk ECs in complex water matrices. The catalyst employs aptamer-engineered binding pockets to preconcentrate ECs (e.g., Bisphenol A (BPA), Oxytetracycline (OTC), Dibutyl phthalate (DBP)) at Fe-Au dual-active sites via conformation-specific docking, while electronic metal-support interactions enhance H₂O₂ activation, achieving a ·OH yield twice that of conventional Fe₃O₄. In the presence of 1,000-fold interferents, the system removes > 95 % of 100 μg/L ECs with 91-97 % selectivity, outperforming homogeneous Fenton systems by 5.3-fold. Molecular docking and in situ spectroscopy reveal that aptamer pocket structures selectively preconcentrate ECs at catalytic sites, enabling localized ·OH attack. The proposed "recognition-destruction" mechanism establishes a novel paradigm for precision remediation of trace high-risk contaminants in complex water systems, bridging molecular biotechnology and environmental catalysis to address real-world water challenges.