Constructing Asymmetric Dual-Site Lanthanide MOF for Sequence-Selective DNA Cleavage

Achieving both efficiency and selectivity in nuclease-mimicking nanozymes remains challenging due to the intrinsic coupling between substrate recognition and catalytic activation. Here we report an asymmetric Yb3+/Yb2+ dual-site nuclease mimic (Yb-BDC-Cl) constructed on lanthanide metal–organic frameworks (Ln-MOFs) scaffolds via a hierarchical spatial decoupling strategy. In this architecture, the asymmetric arrangement decouples substrate recognition and catalytic activation: Yb3+ nodes act as Lewis-acidic anchoring sites for phosphate coordination, whereas Yb2+ centers derived from oxygen vacancies serve as redox-active sites for O2-mediated oxidative cleavage. This spatially segregated configuration enables cooperative DNA cleavage with high efficiency and sequence selectivity toward poly(T) sequences (poly T80, half-life ≈ 2.0 h). Mechanistic and structural investigations confirm the coexistence of asymmetric sites and elucidate that Yb3+-mediated substrate anchoring dictates sequence selectivity, whereas Yb2+-assisted O2 activation governs oxidative reactivity. Guided by these insights, we develop a mechanistically validated dual-pathway inhibitory biosensor with self-calibration capability, providing functional evidence for the operational independence of dual sites. Together, these findings establish asymmetric spatial decoupling as a paradigm for constructing highly efficient and sequence-selective artificial nucleases.