Hierarchically Macro-Microporous Ce-Based MOFs for the Cleavage of DNA

The construction of hierarchically macro-micro-porous metal- organic frameworks (HMMOFs) with thin macroporous walls could afford highly accessible active sites in interconnected skeleton, while it remains a challenge so far. Herein, we achieve open channels with macroporous sizes up to 100 nm and macroporous walls of 11-12 nm in cerium-based MOFs (HMUiO-66(Ce)). Our success stems from the introduction of microemulsion-guided assembly strategy, in which columnar microemulsion was formed with P123 and F127 as costabilizers and toluene as an oil phase to template HMUiO-66(Ce). The assembly mechanism of spherical stacking and epitaxial growth modes was disclosed, hopefully setting a conceptual guideline for the design of extensive HMMOFs. The abundant Ce-OH sites on macroporous walls and free mass diffusion in macroporous channels make HMUiO-66(Ce) competent as nuclease mimic for the hydrolytic cleavage of stable phosphodiester linkages in various DNA, prefiguring their potentials in DNA scissoring-related biological applications such as gene editing, sensing, and therapeutics.