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

Abstract

The construction of hierarchically macro-microporous 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.

Hierarchical large-pore MOFs templated from poly(ethylene oxide)-b-polystyrene diblock copolymer with tuneable pore sizes

“…S12, ESI †) revealed the coexistence of Ce(IV) and Ce(III) species due to the partial reduction of coordination unsaturated Ce(IV)-OH sites to Ce(III). 34 The thermogravimetric analysis manifested that HP-UiO-Ce is stable up to 300 1C (Fig. S13, ESI †), which is similar to the decomposition temperature of previous reported Ce-based UiO-66 MOFs.…”

Constructing strategies for hierarchically porous MOFs with different pore sizes and applications in adsorption and catalysis

“…4a. 24 When compared with the generation of defects or the use of long alkyl chain ligands, the hierarchically porous MOFs constructed using the soft templating method can precisely tune the porosity to form mesopores with uniform pore sizes. The mesopores introduced using the soft templating method typically depend on the size of the micelles formed by the surfactant.…”

“…4 (a) Construction of hierarchically porous UiO-66(Ce) by soft template method. 24 Reprinted with permission from ref. 24.…”

“…In this paper, we introduce the methods used to construct hierarchically porous MOFs from micropores (mostly ligands with different functional groups are introduced), mesoporous (mostly pores formed by defects within the crystals), and macropores (predominantly pores formed by crystal stacking), and present the application advantages of hierarchically porous MOFs in adsorption and catalysis, as shown in Scheme 1. [21][22][23][24][25][26][27][28] 2 Constructing strategies at different pore scales…”

“…In addition, the etched pores are not uniform, which can easily cause pore blockage and the Scheme 1 Constructing strategies of hierarchically porous MOFs with different pore size ranges and their applications in adsorption and catalysis. [21][22][23][24][25][26][27][28] introduction of impurities; the mixed ligand and MOF-on-MOF methods can only be used in a narrow range. Due to these drawbacks, these methods are generally not universal.…”