Engineering Lanthanide Metal‐Organic Framework Nuclease Nanozymes: Unveiling Affinity‐Driven DNA Hydrolysis

ABSTRACT Nuclease nanozymes promise robust, tailorable alternatives to natural nucleases, but suffer from their limited hydrolytic activity due to the Lewis acidity‐centric mechanistic dogma and the unclear role of nanozyme–DNA interactions. Here, we report an affinity‐driven strategy that upends conventional cognition. A series of lanthanide metal‐organic frameworks (Ln‐MOFs) were constructed, with catalytic efficiency decoupled from simple acid strength. Activity increased with the lanthanide atomic number despite a decrease in nanozyme‐DNA affinity. Among these, Yb‐BDC (terephthalic acid‐based) exhibited the highest DNA‐cleaving efficiency reported to date (half‐life ≈ 30 min), yet showed minimal activity toward the traditional model substrate bis(4‐nitrophenyl) phosphate (BNPP), thereby challenging the conventional Lewis acidity‐driven paradigm. This unexpected inverse relationship reveals a critical binding‐release cycle as the true driver of DNA hydrolysis. Capitalizing on this discovery, we developed a synthetic CRISPR/Cas‐inspired biosensing platform by integrating Yb‐BDC with rolling circle amplification, replacing natural nucleases. This system enables ultrasensitive detection of non‐nucleic acid targets, expanding the scope of nanozymes in diagnostic applications. Our findings not only establish host–guest interaction engineering as a new paradigm for nuclease nanozymes design but also pioneer a modular framework for their application in biosensing technologies.