Dual-Single-Atom Catalyst with Aptamer-Engineered Confined Reactive Milieu for Spatiotemporally Controlled Selective Conversion.

Abstract

Spatiotemporal control of short-lived reactive intermediates remains a central challenge in heterogeneous catalysis, as non-selective diffusion fundamentally limits efficiency in complex media. Inspired by enzymatic compartmentalization, we report an aptamer-functionalized Au-Fe dual-single-atom catalyst (Apt-Au₁-Fe₁/NC) that mimics nature's precision by integrating atomically dispersed Au-Fe sites with a genetically engineered recognition element. This material design creates a "smart reactive pocket" featuring two synergistic interfaces: the Au-Fe heteronuclear pair electronically modulates the d-band center to lock the oxygen reduction reaction (ORR) into a highly selective 3-electron pathway with a lowered energy barrier (0.424 eV), while the grafted aptamer acts as a molecular gatekeeper for substrate pre-enrichment. The resulting architecture achieves exceptional selectivity (87.0%-92.6%) for specific targets while suppressing non-specific mineralization to below 5.3%-a stark contrast to conventional systems where selectivity is negligible and mineralization exceeds 90%. Mechanistically, the synergistic electronic interaction ensures localized ·OH generation, while the aptamer enforces a strict "proximity effect," confining these radicals within the nanoscale space for instantaneous consumption by captured substrates. By imposing biological recognition-based spatial constraints on inorganic active centers, this work establishes a universal paradigm for decoupling activity from selectivity, enabling precision chemical conversion in complex matrices.