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The development of metal–organic frameworks for carbon dioxide (CO2) capture has drawn considerable interest among researchers with MIL-101(Cr) gaining significance owing to its high stability. This paper investigates the one-step synthesis of MIL-101-NH2(Cr) by using guanidine hydrochloride as a mediator under relatively mild conditions (aqueous phase, reaction temperature of 120 °C, and without the use of mineralization agents such as hydrofluoric acid). MIL-101-NH2(Cr) not only exhibited a high specific surface area with a Lewis-base site-rich ligand but also possessed a good CO2 adsorption capacity of 3.96 mmol/g at 1 bar. Furthermore, diethylenetriamine (DETA) was loaded into MIL-101-NH2(Cr) to design a new CO2 adsorbent DETA@MIL-101-NH2(Cr). The loaded material maintained the original structure and also displayed an improved adsorption capacity of 0.29 mmol/g under low (< 0.11 bar) CO2 partial pressure. The absorbents possessed good selectivity, stability, and recyclability which make them ideal candidates for CO2 capture. [ABSTRACT FROM AUTHOR]

Spatial functionalization of hierarchically mesoporous metal–organic frameworks (HMMOFs) in a controllable manner is highly desirable yet challenging. Herein, microporous and mesoporous spaces as well as the external surface of nanoscale hierarchically mesoporous UiO-66-NH2 MOFs were site-separately modified to endow them with additional functionalities. Given the pore-filling effect of soft templates, the folic acid ligand was successfully grafted on the outer surface without reducing the pore size and available pore volumes, making the developed sensing nanoprobe competent to specifically identify cancer cells. The mesoporous support not only effectively protected the encapsulated enzymes but also facilitated the proximity between the substrates and enzymes by virtue of the spatial confinement effect. The Cu2+ ions introduced in microporous skeleton could synergistically activate the activity of horseradish peroxidase immobilized in mesopores. Thanks to such enhanced enzymatic activity and spatial functionalities, the designed nanoprobe could specifically and quantitatively check out FR-overexpressed cancer cells in a colorimetric and visible way. Through deliberately screening different functionalities in specific locations of HMMOFs, such a model is expected to set a guideline for the design of multiple-functional diagnostic platform for the detection of various cancers. [ABSTRACT FROM AUTHOR]

In addressing the demand for hierarchically mesoporous metal‐organic frameworks (HMMOFs) with adjustable large mesopores, a method based on the synergistic effects of low‐temperature microemulsions and Hofmeister ions is developed. Low temperature dramatically enhanced the solubility of hydrophobic solvent in the microemulsion core, enlarging the mesopores in HMMOFs replica. Meanwhile, Hofmeister salt‐in ions continuously controlled mesopore expansion by modulating the permeability of swelling agent into the microemulsion core. The large mesopores up to 33 nm provided sufficient space for the alkaline phosphatase (ALP) enrichment, and retained the remaining channel to facilitate the free mass diffusion. Leveraging these advantages, a colorimetric sensor is successfully developed using large‐mesopore HMMOFs for femtomolar ALP detection based on the enrichment and cycling amplification principles. The sensor exhibited a linear detection range of 100 to 7500 fm and a limit of detection of 42 fm, presenting over 4000 times higher sensitivity than classic para‐nitrophenyl phosphate colorimetric methods. Such high sensitivity highlights the importance of adjustable mesoporous structures of HMMOFs in advanced sensing applications, and prefigures their potential for detecting large biomolecules in diagnostics and biomedical research. [ABSTRACT FROM AUTHOR]