Isomorphic MOF-derived porous carbon materials as electrochemical sensor for simultaneous determination of hydroquinone and catechol

Cobalt and zinc nanoparticles from pyrolysis of their MOF precursors exhibiting potent organophosphorus hydrolase-mimicking activities

Cobalt and zinc nanoparticles from pyrolysis of cobalt-containing ZIF-67 and zinc-containing ZIF-90 exhibited potent organophosphorus hydrolase-mimicking activities for the hydrolysis of organophosphorus compounds within minutes at pH 9.0 and 25-40 °C. The resulting nanozymes could find potential applications in many areas such as chemical decontamination, environmental protection and defense of chemical weapons.

Recent progress in the development of porous carbon-based electrodes for sensing applications

Electrochemical (bio)sensors are considered clean and powerful analytical tools capable of converting an electrochemical reaction between analytes and electrodes into a quantitative signal. They are an important part of our daily lives integrated in various fields such as healthcare, food and environmental monitoring. Several strategies including the incorporation of porous carbon materials in its configuration have been applied to improve their sensitivity and selectivity in the last decade. The porosity, surface area, graphitic structure as well as chemical composition of materials greatly influence the electrochemical performance of the sensors. In this review, activated carbons, ordered mesoporous carbons, graphene-based materials, and MOF-derived carbons, which are used to date as crucial elements of electrochemical devices, are described, starting from their textural and chemical compositions to their role in the outcome of electrochemical sensors. Several relevant and meaningful examples about material synthesis, sensor fabrication and applications are illustrated and described. The closer perspectives of these fascinating materials forecast a promising future for the electrochemical sensing field.

Preparation of magnetic MOFs for use as a solid-phase extraction absorbent for rapid adsorption of triazole pesticide residues in fruits juices and vegetables

Detection of low levels of triazole fungicides in agricultural product matrices is important. Although several detection methods have been developed, all have some drawbacks, such as being time-consuming, requiring complex sample pretreatment, and consuming large volumes of organic solvents. There is an urgent need for a simple and rapid detection method for triazole fungicides. In this study, the adsorbent composite material magnetic MOFs based on Fe₃O₄-MWCNT was synthesized by in-situ polymerization at room temperature, and was applied to extract triazole pesticides from fruits and vegetables. High-performance liquid chromatography-tandem mass spectrometry was used for quantification. Under optimized conditions, the constructed detection method showed a low detection (LOD) of 0.52-1.83 μg/L (S/N = 3) and wide linear range of 5.00-500.00 μg/L for triazole fungicides in the fruit and vegetable samples. The method recovery for spiked fungicides (10, 50, and 100 μg/L) in cabbage, spinach, orange juice, and apple juice ranged from 62.80% to 94.20%. The constructed detection method has a lower detection limit than previously reported methods and has a higher sensitivity for triazole pesticide residues in complex matrices.

A Multifunctional Tb-MOF Detector for H2O2, Fe3+, Cr2O7 2-, and TPA Explosive Featuring Coexistence of Binuclear and Tetranuclear Clusters

A novel three-dimensional microporous terbium(III) metal-organic framework (Tb-MOF) named as [Tb10 (DBA)6(OH)4(H2O)5]·(H3O)4 (1), was successfully obtained by a solvothermal method based on terbium nitrate and 5-di(2',4'-dicarboxylphenyl) benzoic acid (H5DBA). The Tb-MOF has been characterized by single crystal X-ray diffraction, elemental analysis, thermogravimetry, and fluorescence properties, and the purity was further confirmed by powder X-ray diffraction (PXRD) analysis. Structural analysis shows that there are two kinds of metal cluster species: binuclear and tetranuclear, which are linked by H5DBA ligands in two μ7 high coordination fashions into a three-dimensional microporous framework. Fluorescence studies show that the Tb-MOF can detect H2O2, Fe3+, and Cr2O7 2- with high sensitivity and selectivity and can also be used for electrochemical detection of exposed 2,4,6-trinitrophenylamine (TPA) in water. The highly selective and sensitive detection ability of the Tb-MOF might make it a potential multifunctional sensor in the future.