Synthesis, post-modification and catalytic properties of metal-organic framework NH2-MIL-53(Al)

Synthesis of Highly Efficient and Recyclable Bimetallic Cox-Fe1-x-MOF for the Synthesis of Xanthan and Removal of Toxic Pb2+ and Cd2+ Ions

Mono-(Fe) and bimetallic Co_x-Fe_1-x-MOF with different Co and Fe contents was successfully synthesized by the solvothermal method. The structural properties of the prepared samples were characterized by X-ray diffraction, transmission electron microscopy (TEM), Brunauer-Emmett-Teller specific surface area, and Fourier transform infrared spectroscopy. The results revealed the successful formation of mono and mixed Co_x-Fe_1-x-MOF. Also, the results of TEM displayed that the particle structure of Co_x-Fe_1-x-MOF changed to octahedral after the addition of cobalt. The surface acidity results illustrated that the samples showed both Lewis and Brønsted acid sites, and Co_x-Fe_1-x-MOF possessed more surface acidity than Fe-MOF. The catalytic performance of the prepared samples was tested by synthesis of 14-phenyl-14H-dibenzo [a, j] xanthene (xanthene), and bimetallic Co_x-Fe_1-x-MOF showed higher activity compared to monometallic Fe-MOF. The sample with Co_0.50-Fe_0.50-MOF gave the highest yield of xanthene with 90.2%. In addition, the prepared samples were used for removal of Pb²⁺ and Cd²⁺ ions from the aqueous solution. The sample with Co_0.50-Fe_0.50-MOF showed the highest removal efficiency compared with mono- and other bimetallic samples. The results illustrated that the addition of Co to Fe enhanced the structural properties, acidity, and catalytic performance of the prepared samples due to the synergistic effect between Fe and Co ions. According to the obtained results, the prepared samples showed great potentials for the synthesis of pharmacologically active compounds and environmental protection.

An ultralow concentration of Al-MOFs for turn-on fluorescence detection of aflatoxin B1 in tea samples

A turn-on fluorescent sensing platform based on an ultralow concentration of Al-metal organic frameworks for the detection of aflatoxin B₁ has been developed for the first time. This fluorescence turn-on sensor exhibits the largest fluorescence enhancement (or quenching) constant value of 179404 M^-1 among all luminescence-based chemical sensors reported till date. Moreover, the sensor afforded a rapid detection of aflatoxin B₁, with a linear response in the concentration range of 0.05-9.61 μM and a low detection limit of 11.67 ppb. Additionally, the fabricated sensor showed good repeatability, reproducibility, stability, and selectivity. Most importantly, the practical application of this sensor has been demonstrated by detecting aflatoxin B₁ in complex tea samples with low relative standard deviation (≤7.72%; n = 3) and satisfactory recoveries. In summary, the proposed method has great potential as a simple, sensitive and selective strategy for monitoring aflatoxin B₁ in food samples.

DNA hybridization-induced fluorescence variation in ThT: a new strategy of developing aqueous sensors for MO genes

MOFs-based sensors for detecting the Mycoplasma ovipneumoniae (MO) using binding-induced dynamic DNA assembly exhibits perfect selectivity, low detection limitation and wide linear range not only in buffer, but also in natural complex media.

Applications of water-stable metal-organic frameworks in the removal of water pollutants: A review

Because the pollutants produced by human activities have destroyed the ecological balance of natural water environment, and caused severe impact on human life safety and environmental security. Hence the task of water environment restoration is imminent. Metal-organic frameworks (MOFs), structured from organic ligands and inorganic metal ions, are notable for their outstanding crystallinity, diverse structures, large surface areas, adsorption performance, and excellent component tunability. The water stability of MOFs is a key requisite for their possible actual applications in separation, catalysis, adsorption, and other water environment remediation areas because it is necessary to safeguard the integrity of the material structure during utilization. In this article, we comprehensively review state-of-the-art research progress on the promising potential of MOFs as excellent nanomaterials to remove contaminants from the water environment. Firstly, the fundamental characteristics and preparation methods of several typical water-stable MOFs include UiO, MIL, and ZIF are introduced. Then, the removal property and mechanism of heavy metal ions, radionuclide contaminants, drugs, and organic dyes by different MOFs were compared. Finally, the application prospect of MOFs in pollutant remediation prospected. In this review, the synthesis methods and application in water pollutant removal are explored, which provide ways toward the effective use of water-stable MOFs in materials design and environmental remediation.

MOF-assisted antifouling material: application in rapid determination of TB gene in whole-serum specimens

Biofouling is a nuisance in the practical applications of biosensors, which seriously affects the reliability and accuracy of detection. The utilization of antifouling interface materials is a promising option for mitigating biofouling. Only highly accumulated antifouling polymeric surfaces tend to offer "zero" nonspecific protein adsorption. Herein, superior antifouling coatings based on chondroitin sulfate (CS) were prepared by the NH₂-MIL-53 (Al) assisted strategy. This is a novel design to improve the antifouling property of material by taking advantage of the high specific surface area of the three-dimensional MOF to increase the accumulation degree of antifouling functional groups per unit area. And the related chemical technology is simple and easy to operate. As expected, this novel CS-loaded MOF demonstrated an excellent antifouling performance in various biological samples, even in 100% goat serum. Only 8.48% changes of differential pulse voltammetry (DPV) were found. Furthermore, this antifouling interface material is successfully applied for the specific detection of the tuberculosis (TB) gene in undiluted biofluids. This developed TB biosensor showed a high analytical performance with a wide linear range (1.00 × 10^-16 M to 1.00 × 10^-11 M) and a low detection limit, indicating that it may open new avenues for direct biosensing of disease markers for clinical samples.

A novel sensitive and selective chemosensor for fluorescent detection of Zn2+ in cosmetics creams based on a covalent post functionalized Al-MOF

A material was fabricated based on the Schiff base reaction to achieve covalent attachment of NH₂-MIL-53(Al) and 3-formylsalicylic acid for fluorimetric detection of Zn²⁺ ions based on inhibition and destruction of CN isomerization and ESIPT.

CoII immobilized on an aminated magnetic metal–organic framework catalyzed C–N and C–S bond forming reactions: a journey for the mild and efficient synthesis of arylamines and arylsulfides

The catalytic activity of Fe₃O₄@AMCA-MIL53(Al)-NH₂-Co^II NPs as a novel and inexpensive catalyst was investigated in the C–N and C–S cross coupling reactions.

Amine-functionalized MIL-53(Al) with embedded ruthenium nanoparticles as a highly efficient catalyst for the hydrolytic dehydrogenation of ammonia borane

The performance of Ru-based catalyst for hydrolysis of AB can be significantly enhanced through amine-functionalization of the MOF material.