Comment on "Database for CO2 Separation Performances of MOFs Based on Computational Materials Screening"

A novel electrochemical biosensor based on MIL-101-NH2 (Cr) combining target-responsive releasing and self-catalysis strategy for p53 detection

A novel electrochemical biosensor was constructed to detect p53 gene based on MIL-101-NH₂ (Cr) by combining target-responsive releasing and self-catalysis strategy. MIL-101-NH₂ (Cr) with suitable pore structure was used to encapsulate methylene blue (MB) as signal probe. The hairpin DNA (HP) containing rich-G sequences was used as gatekeeper to seal up the pores and avoid MB leakage through covalent immobilization. The p53 gene could hybridize with the loop portion of HP for the formation of dsDNA, which had the specific nicking site of the nicking endonuclease (Nt.BstNBI). Then Nt.BstNBI recognized the specific recognition site and cleaved HP to open the pore for releasing of MB. Meanwhile, the cleavage of HP released the target DNA to trigger the target recycling for signal amplification. More importantly, the plentiful rich-G sequences were exposed to form Hemin/G-quadruplex DNAzymes, which could unite MIL-101-NH₂ (Cr) to catalyze redox reaction of MB released by itself for signal amplification. The biosensor for p53 had wide linear range from 1 × 10^-14 to 1 × 10^-7 M and a low detection limit of 1.4 × 10^-15 M. The combination of target-responsive releasing and self-catalysis strategy provided a promising way for constructing ultrasensitive and simple biosensor.

High-Performance, Free-Standing Symmetric Hybrid Membranes for Osmotic Separation

The internal concentration polarization (ICP) of asymmetric osmotic membranes with support layers greatly reduced membrane water permeability, therefore compromising membrane performance. In this study, a series of free-standing symmetric hybrid forward osmosis (FO) membranes without experiencing ICP were fabricated by covalently linking metal-organic framework (MOF) nanofillers with a polymer matrix. Owing to the introduction of MOFs, which allow only water permeation but reject salts by steric hindrance, the prepared hybrid membranes could approach the empirical permeability-selectivity trade-off. The optimized hybrid membrane displayed an outstanding water/Na₂SO₄ selectivity of ∼1208.4 L mol^-1, compared with that of conventional membranes of ∼375.6 L mol^-1. Additionally, the fabricated hybrid membranes showed excellent mechanical robustness, maintaining structural integrity during the long-term FO separation of high-salinity solution. This work provides an effective methodology to fabricate high-performance, symmetric MOF-based membranes for osmotic separation processes such as seawater desalination and water purification.

In Silico Investigation into H2 Uptake in MOFs: Combined Text/Data Mining and Structural Calculations

Metal-organic frameworks (MOFs) with high surface areas and adjustable lattice structures are attractive for gas storage and thus have been a great interest in research. Although tremendous amount of data on MOFs have been available in the literature, there are very few studies considering methodological approach for H₂ uptake properties of MOFs. In this study, we systematically investigated the H₂ uptake capabilities of MOFs by means of text and data mining (TDM) through retrieving data of the surface areas (SA) and pore volumes (PV) from published manuscripts. In addition, we calculated theoretical SA and PV values of all real MOFs available in Cambridge Structural Database (CSD). Prior to calculation, we applied an automated structure analysis algorithm that loads the coordinates of molecules from CSD experimental X-ray single-crystal structure and removes guest/solvent contaminants from the structure. We compared SA, PV, and H₂ uptake data from both TDM and structural calculation techniques and unraveled a list of MOFs with H₂ uptakes predicted from both experimental and theoretical SA/PV values that may be regarded as the most promising candidates for H₂ storage. The extensive and systematic TDM strategy estimates 5975 experimental SA and 7748 experimental PV values (2080 MOFs with SA + PV values) with 78-82% success rate. In addition, structural calculations reveal the theoretical SA and PV values along with a theoretical H₂ adsorption limit of MOFs in the absence of guest molecules. Combination of both TDM and structural calculation strategies provides a more comprehensive perspective for the investigation of hydrogen storage capacities in MOFs, which elucidates plausibility of new compounds as candidates for H₂ storage materials.

Enabling efficient exploration of metal–organic frameworks in the Cambridge Structural Database

A tutorial review for mining the ever growing number of metal–organic frameworks data in the Cambridge Structural Database, for MOF scientists of all backgrounds.

The role of molecular modelling and simulation in the discovery and deployment of metal-organic frameworks for gas storage and separation

Metal-organic frameworks (MOFs) are highly tuneable, extended-network, crystalline, nanoporous materials with applications in gas storage, separations, and sensing. We review how molecular models and simulations of gas adsorption in MOFs have informed the discovery of performant MOFs for methane, hydrogen, and oxygen storage, xenon, carbon dioxide, and chemical warfare agent capture, and xylene enrichment. Particularly, we highlight how large, open databases of MOF crystal structures, post-processed to enable molecular simulations, are a platform for computational materials discovery. We discuss how to orient research efforts to routinise the computational discovery of MOFs for adsorption-based engineering applications.