No abstract

Though many efforts have been devoted to the adsorptive removal of hazardous materials of organophosphorus pesticides (OPs), it is still highly desirable to develop novel adsorbents with high adsorption capacities. In the current work, the removal of two representative OPs, glyphosate (GP) and glufosinate (GF), was investigated by the exceptionally stable Zr-based MOFs of UiO-67. The abundant Zr-OH groups, resulting from the missing-linker induced terminal hydroxyl groups and the inherent bridging ones in Zr-O clusters of UiO-67 particles, served as natural anchorages for efficient GP and GF capture in relation with their high affinity toward phosphoric groups in OPs. The correlation between the most significant parameters such as contact time, OPs concentration, adsorbent dose, pH, as well as ionic strength with the adsorption capacities was optimized, and the effects of these parameters on the removal efficiency of GP and GF from the polluted aqueous solution were investigated. The adsorption of GP on UiO-67 was faster than that of GF, and a pseudo-second-order rate equation effectively described the uptake kinetics. The Langmuir model exhibited a better fit to adsorption isotherm than the Freundlich model. Thanks to the strong affinity and adequate pore size, the adsorption capacities in UiO-67 approached as high as 3.18 mmol (537 mg) g(-1) for GP and 1.98 mmol (360 mg) g(-1) for GF, which were much higher than those of many other reported adsorbents. The excellent adsorption characteristics of the current adsorbents toward OPs were preserved in a wide pH window and high concentration of the background electrolytes. These prefigured the promising potentials of UiO-67 as novel adsorbent for the efficient removal of OPs from aqueous solution.

Zr–O clusters and BDC-NH2 linkers in Zr-MOFs were individually designed as recognition sites and fluorescent reporters for phosphate sensing.

Ordered mesoporous metal–organic frameworks (mesoMOFs) were constructed with a uniform pore size up to about 10 nm and thick microporous walls, opening up the possibility for the mass diffusion of large‐size molecules through crystalline MOFs. The synergistic effects based on triblock copolymer templates and the Hofmeister salting‐in anions promote the nucleation of stable MOFs in aqueous phase and the in situ crystallization of MOFs around templates, rendering the generation of a microcrystal with periodically arranged large mesopores. The improved mass transfer benefiting from large‐pore channels, together with robust microporous crystalline structure, endows them as an ideal nanoreactor for the highly efficient digestion of various biogenic proteins. This strategy could set a guideline for the rational design of new ordered large‐pore mesoMOFs with a variety of compositions and functionalities and pave a way for their potential applications with biomacromolecules.

Introduction of large pore in the primitive microporous metal–organic frameworks (MOFs) with tailorable particle size can endow them with desired properties for potential applications in the intracellular delivery of membrane‐impermeable proteins. However, no research is found to focus on this topic until now. Herein, a monocarboxylic acid (MA) and organic base comodulation strategy is developed to synthesize the hierarchically porous UiO‐66 nanoparticles. MA of dodecanoic acid is utilized to control the pore size while trimethylamine (TEA) plays a key role in modulating the nucleation of crystallization to regulate the particle size. In comparison with microporous UiO‐66, a model protein of cytochrome c (Cyt c) could be efficiently loaded into the mesoporous MOFs (mesoMOFs). The size‐dependent cellular uptake is also evaluated, and it is verified that mesoMOFs with particle size of 90 nm could be endocytosed into living cells with highest efficiency. These outstanding merits enable the current mesoMOFs not only to exhibit efficient encapsulation of Cyt c but also facilitate the protein delivery into the cytosol and subsequent endosomal escape. Given the exceptional chemical stability, hierarchically porous structure as well as tunable particle size, the elaborated mesoUiO‐66 nanoparticles might offer a promising platform for a variety of biomedical applications.