A new strategy for the development of efficient impedimetric tobramycin aptasensors with metallo-covalent organic frameworks (MCOFs)

Interlayer Polymerization to Construct a Fully Conjugated Covalent Organic Framework as a Metal-Free Oxygen Reduction Reaction Catalyst for Anion Exchange Membrane Fuel Cells

Two-dimensional (2D) covalent organic frameworks (COFs) have a multilayer skeleton with a periodic π-conjugated molecular array, which can facilitate charge carrier transport within a COF layer. However, the lack of an effective charge carrier transmission pathway between 2D COF layers greatly limits their applications in electrocatalysis. Herein, by employing a side-chain polymerization strategy to form polythiophene along the nanochannels, a conjugated bridge is constructed between the COF layers. The as-synthesized fully conjugated COF (PTh-COF) exhibits high oxygen reduction reaction (ORR) activity with narrowed energy band gaps. Correspondingly, PTh-COF is tested as a metal-free cathode catalyst for anion exchange membrane fuel cells (AEMFCs) which showed a maximum power density of 176 mW cm-2 under a current density of 533 mA cm-2. The density functional theory (DFT) calculation reveals that interlayer conjugated polythiophene optimizes the electron cloud distribution, which therefore enhances the ORR performance. This work not only provides new insight into the construction of a fully conjugated covalent organic framework but also promotes the development of new metal-free ORR catalysts.

State-of-the-art electrochemical biosensors based on covalent organic frameworks and their hybrid materials

As the development of global population and industry civilization, the accurate and sensitive detection of intended analytes is becoming an important and great challenge in the field of environmental, medical, and public safety. Recently, electrochemical biosensors have been constructed and used in sensing fields, such as antibiotics, pesticides, specific markers of cancer, and so on. Functional materials have been designed and prepared to enhance detection performance. Among all reported materials, covalent organic frameworks (COFs) are emerging as porous crystalline materials to construct electrochemical biosensors, because COFs have many unique advantages, including large surface area, high stability, atom-level designability, and diversity, to achieve a far better sensing performance. In this comprehensive review, we not only summarize state-of-the-art electrochemical biosensors based on COFs and their hybrid materials but also highlight and discuss some typical examples in detail. We finally provide the challenge and future perspective of COFs-based electrochemical biosensors.

Novel electrochemical sensing strategy for ultrasensitive detection of tetracycline based on porphyrin/metal phthalocyanine-covalent organic framework

In this work, a novel two-dimensional semiconducting metal covalent organic framework (CuTAPc-TFPP-COF) was synthesized and used as biosensing platform to construct aptasensor for trace detection of tetracycline (TC). The CuTAPc-TFPP-COF integrates the highly conjugated structure, large specific surface area, high porosity, abundant nitrogen functional groups, excellent electrochemical activity, and strong bioaffinity for aptamers, providing abundant active sites to effectively anchor aptamer strands. As a result, the CuTAPc-TFPP-COF-based aptasensor shows high sensitivity for detecting TC via specific recognition between aptamer and TC to form Apt-TC complex. An ultralow detection limit of 59.6 fM is deduced from the electrochemical impedance spectroscopy within a wide linear range of 0.1-100000 pM for TC. The CuTAPc-TFPP-COF-based aptasensor also exhibits good selectivity, reproducibility, stability, regenerability, and excellent applicability for real river water, milk, and pork samples. Therefore, the CuTAPc-TFPP-COF-based aptasensor will be promising for detecting trace harmful antibiotics residues in environmental water and food samples.

Detection mechanism and the outlook of metal-organic frameworks for the detection of hazardous substances in milk

Milk has a high nutritional value. However, milk is easily contaminated in the production, processing, and storage processes, which harms consumers' health. Therefore, the harmful substances' detection in milk is important. Metal-organic frameworks (MOFs) have proven high potential in food safety detection due to their unique porous structure, large effective surface area, large porosity, and structural tunability. This article systematically describes the detection mechanism of fluorescence, electrochemical, colorimetric, and enzyme-linked immunosorbent assay based on MOFs. The progress of the application of MOFs in the detection of antibiotics, harmful microorganisms and their toxins, harmful ions, and other harmful substances in milk in recent years is reviewed. The structural tunability of MOFs enables them to be functionalized, giving the ability to be applied to different detection methods or substances. Therefore, MOFs can be used as an advantageous sensing material for detecting harmful substances in the complex environment of milk.

Molecularly imprinted electrochemical sensor based on metal-covalent organic framework for specifically recognizing norfloxacin from unpretreated milk

Here, a molecularly imprinted electrochemical sensor (MIECS) was designed and fabricated for specifically monitoring norfloxacin (NFX), an entirely synthetic antibiotic. In which, Cu2+ dopped covalent organic framework (COF) was used to connect NFX imprinting layer and glassy carbon electrode through covalence. Under optimized conditions, the linear range is as wide as 5 orders of magnitude, and the detection limit is 5.94 × 10-3 μM (estimated based on S/N = 3). Average recoveries are among 92.4%-99.0% with relative standard deviations ≤ 4.05% (n = 3) in (spiked) whole, low-fat, and skimmed milk, validated by independent HPLC assays. The excellent performance can be ascribed to the significant recognition and enriching ability of the imprinting layer, improved conductivity of Cu2+ dopped covalent organic framework, and high stability of covalence between layers. We hope the work will act as a model of MIECSs for rapidly and selectively detecting trace drug residue in complex real samples.

Defective porphyrin-based metal-organic framework nanosheets derived from V2CTx MXene as a robust bioplatform for impedimetric aptasensing 17β-estradiol

An electrochemical aptasensor was prepared for the efficient, sensitive, and selective detection of 17β-estradiol. The sensor was based on a defective two-dimensional porphyrin-based metal-organic framework derived from V₂CT_x MXene. The resulting metal-organic framework nanosheets benefited from the advantages of V₂CT_x MXene nanosheets and porphyrin-based metal-organic framework, two-dimensional porphyrin-based metal-organic framework nanosheets demonstrated amplified electrochemical response and enhanced aptamer-immobilization ability compared with V₂CT_x MXene nanosheets. The sensor's detection limit was ultralow at 0.81 fg mL^-1 (2.97 fM), and the 17β-estradiol concentration range was wide, thereby outperforming most reported aptasensors. The high selectivity, superior stability and reproducibility, and excellent regeneration performance of the constructed aptasensor indicated its remarkable potential application for 17β-estradiol determination in diverse real samples. This aptasensing strategy can be used to analyze other targets by replacing the corresponding aptamer.

Review: Synthesis of metal organic framework-based composites for application as immunosensors in food safety

Ensuring food safety continues to be one of the major global challenges. For effective food safety monitoring, fast, sensitive, portable, and efficient food safety detection strategies must be devised. Metal organic frameworks (MOFs) are porous crystalline materials that have attracted attention for use in high-performance sensors for food safety detection owing to their advantages such as high porosity, large specific surface area, adjustable structure, and easy surface functional modification. Immunoassay strategies based on antigen-antibody specific binding are one of the important means for accurate and rapid detection of trace contaminants in food. Emerging MOFs and their composites with excellent properties are being synthesized, providing new ideas for immunoassays. This article summarizes the synthesis strategies of MOFs and MOF-based composites and their applications in the immunoassays of food contaminants. The challenges and prospects of the preparation and immunoassay applications of MOF-based composites are also presented. The findings of this study will contribute to the development and application of novel MOF-based composites with excellent properties and provide insights into advanced and efficient strategies for developing immunoassays.

Recent Progress of Covalent Organic Frameworks Applied in Electrochemical Sensors

As an emerging porous crystalline organic material, the covalent organic frameworks (COFs) are given more and more attention in many fields, such as gas storage and separation, catalysis, energy storage and conversion, luminescent devices, drug delivery, pollutant adsorption and removal, analysis and detection due to their special advantages of high crystallinity, flexible designability, controllable porosities and topologies, intrinsic chemical and thermal stability. In recent years, the COFs are applied in analytical chemistry, for instance, chromatography, solid-phase microextraction, luminescent and colorimetric sensing, surface-enhanced Raman scattering and electroanalytical chemistry. The COFs decorated electrodes show high performance for detecting trace substances with remarkable selectivity and sensitivity, such as heavy metal ions, glucose, hydrogen peroxide, drugs, antibiotics, explosives, phenolic compounds, pesticides, disease metabolites and so on. This review mainly summarized the application of COF based electrochemical sensor according to different target analytes.

Schottky Junction Nanozyme Based on Mn-Bridged Co-Phthalocyanines and Ti3C2Tx Nanosheets Boosts Integrative Type I and II Photosensitization for Multimodal Cancer Therapy

Cancer phototheranostics have the potential for significantly improving the therapeutic effectiveness, as it can accurately diagnose and treat cancer. However, the current phototheranostic platforms leave much to be desired and are often limited by tumor hypoxia. Herein, a Schottky junction nanozyme has been established between a manganese-bridged cobalt-phthalocyanines complex and Ti₃C₂T_x MXene nanosheets (CoPc-Mn/Ti₃C₂T_x), which can serve as an integrative type I and II photosensitizer for enhancing cancer therapeutic efficacy via a photoacoustic imaging-guided multimodal chemodynamic/photothermal/photodynamic therapy strategy under near-infrared (808 nm) light irradiation. The Schottky junction not only possessed a narrow-bandgap, enhanced electron-hole separation ability and exhibited a potent redox potential but also enabled improved H₂O₂ and O₂ supplying performances in vitro. Accordingly, the AS1411 aptamer-immobilized CoPc-Mn/Ti₃C₂T_x nanozyme illustrated high accuracy and excellent anticancer efficiency through a multimodal therapy strategy in in vitro and in vivo experiments. This work presents a valuable method for designing and constructing a multifunctional nanocatalytic medicine platform for synergistic cancer therapy of solid tumors.

Robust tag-free aptasensor for monitoring of tobramycin: Architecting of rolling circle amplification and fluorescence synergism

With the unpredictable risks on human health and ecological safety, tobramycin (TOB) as an extensively applied antibiotic has embraced global concern. Herein, a label-free fluorescent aptasensor was developed that opened up an innovative sensing strategy for monitoring trace TOB levels. Based on the rolling circle amplification (RCA) process, a giant DNA building was established by the catalytic action of T4 DNA ligase and Phi 29 DNA polymerase with the cooperation of the specific aptamer as a primer skeleton. By having the role of signal amplifier template, the RCA product with the G-quadruplex sequence duplications was decorated by a high number of the thioflavin T (ThT) fluorescent dyes. The aptasensor with good selectivity toward TOB achieved a detection limit as low as 150 pM. Thanks to its accurate target quantification, ease of operation, economic manufacture, as well as high potency for real-time and point-of-care testing, the represented aptasensor is superb for clinical application and food safety control.

Covalent organic framework: A state-of-the-art review of electrochemical sensing applications

Covalent organic framework (COF), a kind of porous polymer with crystalline properties, is a periodic porous framework material with precise regulation at atomic level, which can be formed by the orderly connection of pre-designed organic construction units through covalent bonds. Compared with metal-organic frameworks, COFs exhibit unique performance, including tailor-made functions, stronger load ability, structural diversity, ordered porosity, intrinsic stability and excellent adsorption features, are more conducive to the expansion of electrochemical sensing applications and the universality of applications. In addition, COFs can accurately integrate organic structural units with atomic precision into ordered structures, so that the structural diversity and application of COFs can be greatly enriched by designing new construction units and adopting reasonable functional strategies. In this review, we mainly summarized state-of-the-art recent advances of the classification and synthesis strategy of COFs, the design of functionalized COF for electrochemical sensors and COFs-based electrochemical sensing. Then, an overview of the considerable recent advances made in applying outstanding COFs to establish electrochemical sensing platform, including electrochemical sensor based on voltammetry, amperometry, electrochemical impedance spectroscopy, electrochemiluminescence, photoelectrochemical sensor and others. Finally, we discussed the positive outlooks, critical challenges and bright directions of COFs-based electrochemical sensing in the field of disease diagnosis, environmental monitoring, food safety, drug analysis, etc.

Covalent organic frameworks (COFs) and metal-organic frameworks (MOFs) as electrochemical sensors for the efficient detection of pharmaceutical residues

Pharmaceutical residues are the undecomposed remains from drugs used in the medical and food industries. Due to their potential adverse effects on human health and natural ecosystems, they are of increasing worldwide concern. The acute detection of pharmaceutical residues can give a rapid examination of their quantity and then prevent them from further contamination. Herein, this study summarizes and discusses the most recent porous covalent-organic frameworks (COFs) and metal-organic frameworks (MOFs) for the electrochemical detection of various pharmaceutical residues. The review first introduces a brief overview of drug toxicity and its effects on living organisms. Subsequently, different porous materials and drug detection techniques are discussed with materials' properties and applications. Then the development of COFs and MOFs has been addressed with their structural properties and sensing applications. Further, the stability, reusability, and sustainability of MOFs/COFs are reviewed and discussed. Besides, COFs and MOFs' detection limits, linear ranges, the role of functionalities, and immobilized nanoparticles are analyzed and discussed. Lastly, this review summarized and discussed the MOF@COF composite as sensors, the fabrication strategies to enhance detection potential, and the current challenges in this area.

Synthesis characterization of Zn-based MOF and their application in degradation of water contaminants

Metal-organic frameworks (MOFs) are currently popular porous materials with research and application value in various fields such as medicine and engineering. Aiming at the application of MOFs in photocatalysis, this paper mainly reviews the main synthesis methods of ZnMOFs and the latest research progress of Zn MOF-based photocatalysts to degrade organic pollutants in water, such as organic dyes. This nanomaterial is being used to treat wastewater and has proven to be very efficient because of its exceptionally large surface area and porous nature. The results show that Zn-MOFs are capable of high degradation of the above pollutants and over 90% of degradation was observed in publications. In addition, the reusability percentage was examined and studies showed that the Zn-MOF nanostructure has very good stability and can continue to degrade a high percentage of pollutants after several cycles. This review focuses on Zn-MOFs and their composites. First, the methods of synthesis and characterization of these compounds are given. Finally, the application of these composites in the process of photocatalytic degradation of dye pollutants such as methylene blue, methyl orange, crystal violet, rhodamine B, etc. is explained.

A novel approach based on the ultrasonic-assisted microwave method for the efficient synthesis of Sc-MOF@SiO2 core/shell nanostructures for H2S gas adsorption: A controllable systematic study for a green future

In this work, for the first time, novel Sc-MOF@SiO₂ core/shell nanostructures have been synthesized under the optimal conditions of ultrasonic-assisted microwave routes. The final products showed small particle size distributions with homogeneous morphology (SEM results), high thermal stability (TG curve), high surface area (BET adsorption/desorption techniques), and significant porosity (BJH method). The final nanostructures of Sc-MOF@SiO₂ core/shell with such distinct properties were used as a new compound for H₂S adsorption. It was used with the systematic investigation based on a 2^K−1 factorial design, which showed high-performance adsorption of about 5 mmol/g for these novel adsorbents; the optimal experimental conditions included pressure, 1.5 bar; contact time, 20 min; and temperature, 20°C. This study and its results promise a green future for the potential control of gas pollutants.

Adsorption of paratoluic acid on MIL-53 (Al) metal-organic framework, and response surface methodology optimization

In this study, an organic metal framework adsorbent was used to remove paratoluic acid from aqueous solutions. The effect of various parameters such as pH, initial concentration of paravoluic acid, contact time, and amount of adsorbent was investigated by experimental design method. Central composite design (CCD) was used to optimize paratoluic acid uptake. Initially, MIL-53 (Al) was synthesized, and characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), spectroscopy, and thermogravimetry (TGA). The results of central composite design showed that pH is the most essential factor in the removal of paratoluic acid with MIL-53 (Al). The maximum removal efficiency of paratoluic acid by MIL-53 (Al) adsorbent is 93.67%, the optimal amount of adsorbent is 0.396 g, the optimal time is 35.67 min, the initial concentration is 11.12 mg L−1. The pH is 6.6 with the desired amount 1 is. Isothermal, and kinetic models have also examined. The maximum adsorption capacity was 132.05 (mg g−1), and the adsorption data of MIL-53 (Al) were well consistent with the quasi-second order, and Langmuir isotherm models.

Metal-organic frameworks for pharmaceutical and biomedical applications

Metal-organic framework (MOF) materials provide unprecedented opportunities for evaluating valuable compounds for various medical applications. MOFs merged with biomolecules, used as novel biomaterials, have become particularly useful in biological environments. Bio-MOFs can be promising materials in the global to avoid utilization above toxicological substances. Bio-MOFs with crystallin and porosity nature offer flexible structure via bio-linker and metal node variation, which improves their wide applicability in medical science.

Facile synthesis of Cu NPs@Fe3O4-lignosulfonate: Study of catalytic and antibacterial/antioxidant activities

Environmental pollution is one of the important concerns for human health. There are different types of pollutants and techniques to eliminate them from the environment. We hereby report an efficient method for the remediation of environmental contaminants through the catalytic reduction of the selected pollutants. A green method has been developed for the immobilization of copper nanoparticles on magnetic lignosulfonate (Cu NPs@Fe₃O₄-LS) using the aqueous extract of Filago arvensis L. as a non-toxic reducing and stabilizing agent. The characterization of the prepared Cu NPs@Fe₃O₄-LS was achieved by vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), high resolution TEM (HRTEM), X-ray diffraction (XRD), scanning TEM (STEM), thermogravimetry-differential thermal analysis (TG/DTA), fast Fourier transform (FFT), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron (XPS) analyses. The synthesized Cu NPs@Fe₃O₄-LS was applied as a magnetic and green catalyst in the reduction of Congo Red (CR), 4-nitrophenol (4-NP), and methylene blue (MB). The progress of the reduction reactions was monitored by UV-Vis spectroscopy. Finally, the biological properties of the Cu NPs@Fe₃O₄-LS were investigated. The prepared catalyst demonstrated excellent catalytic efficiency in the reduction of CR, 4-NP, and MB in the presence of sodium borohydride (NaBH₄) as the reducing agent. The appropriate magnetism of Cu NPs@Fe₃O₄-LS made its recovery very simple. The advantages of this process include a simple reaction set-up, high and catalytic antibacterial/antioxidant activities, short reaction time, environmentally friendliness, high stability, and easy separation of the catalyst. In addition, the prepared Cu NPs@Fe₃O₄-LS could be reused for four cycles with no significant decline in performance.

Electrochemical monitoring sensors of water pollution systems

Analytical techniques as strong, precise, and expensive are necessary for monitoring food and water safety for contaminants, microorganisms, and allergies that might be harmful if used. Sudan dyes are commonly utilized as an ingredient in food dye substances and a variety of industrial items. These colors are classified as three carcinogens and are linked to liver and bladder cancers. They are not authorized for human consumption by the International Agency for Research on Cancer (IARC) and are not permitted to be used by the Food Standards Agency or the European Union. This article describes electrochemical dye analysis beside the numerous electrochemical sensors utilized to identify these dyes as a food colorant and water. As a result, the qualities, chemistry, and toxicity of dyes as food colorants and industrial goods in Sudan have been investigated in this study. Sudan dyes have been thoroughly studied, and many electrochemical sensors have been developed to define and monitor these dyes in food colorants. As a result, current electrochemical sensors have been found to be neither mass-production nor cost-effective. Mostly, the synthesis of high-performance materials needs high knowledge, and the production of electrode surfaces is remained difficult due to labor-intensive and time-consuming activities.

An Efficient Ultrasound-Assisted Synthesis of Cu/Zn Hybrid MOF Nanostructures With High Microbial Strain Performance

Metal organic frameworks (MOFs) are a promising choice for antibacterial and antifungal activity due to their composition, unique architecture, and larger surface area. Herein, the ultrasonic method was used to synthesize the Cu/Zn-MOF material as an effective hybrid nanostructure with ideal properties. SEM images were used to investigate the product's morphology and particle size distribution. The XRD pattern revealed that the Cu/Zn hybrid MOF nanostructures had a smaller crystalline size distribution than pure Cu and Zn-MOF samples. Furthermore, the BET technique determined that the hybrid MOF nanostructures had a high specific surface area. TG analysis revealed that the hybrid MOF structures were more thermally stable than pure samples. The final product, with remarkable properties, was used as a new option in the field of antibacterial studies. Antibacterial activity was assessed using MIC and MBC against Gram negative and Gram positive strains, as well as antifungal activity using MIC and MFC. The antimicrobial properties of the synthesized Cu/Zn hybrid MOF nanostructures revealed that they were more effective than commercial drugs in some cases. This study's protocol could be a new strategy for introducing new hybrid nanostructures with specific applications.

Electrochemical α-fetoprotein immunosensor based on Fe3O4NPs@covalent organic framework decorated gold nanoparticles and magnetic nanoparticles including SiO2@TiO2

The early diagnosis of major diseases such as cancer is typically a major issue for humanity. Human α-fetoprotein (AFP) as a sialylated glycoprotein is of approximately 68 kD molecular weight and is considered to be a key biomarker, and an increase in its level indicates the presence of liver, testicular, or gastric cancer. In this study, an electrochemical AFP immunosensor based on Fe₃O₄NPs@covalent organic framework decorated gold nanoparticles (Fe₃O₄ NPs@COF/AuNPs) for the electrode platform and double-coated magnetic nanoparticles (MNPs) based on SiO₂@TiO₂ (MNPs@SiO₂@TiO₂) nanocomposites for the signal amplification was fabricated. The immobilization of anti-AFP capture antibody was successfully performed on Fe₃O₄ NPs@COF/AuNPs modified electrode surface by amino-gold affinity, while the conjugation of anti-AFP secondary antibody on MNPs@SiO₂@TiO₂ was achieved by the electrostatic/ionic interactions. Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) analysis, cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) techniques were used to characterize the nanostructures in terms of physical and electrochemical features. The limit of detection (LOD) was 3.30 fg mL^-1. The findings revealed that the proposed electrochemical AFP immunosensor can be effectively used to diagnose cancer.

Electrochemical Aptasensors for Antibiotics Detection: Recent Achievements and Applications for Monitoring Food Safety

Antibiotics are often used in human and veterinary medicine for the treatment of bacterial diseases. However, extensive use of antibiotics in agriculture can result in the contamination of common food staples such as milk. Consumption of contaminated products can cause serious illness and a rise in antibiotic resistance. Conventional methods of antibiotics detection such are microbiological assays chromatographic and mass spectroscopy methods are sensitive; however, they require qualified personnel, expensive instruments, and sample pretreatment. Biosensor technology can overcome these drawbacks. This review is focused on the recent achievements in the electrochemical biosensors based on nucleic acid aptamers for antibiotic detection. A brief explanation of conventional methods of antibiotic detection is also provided. The methods of the aptamer selection are explained, together with the approach used for the improvement of aptamer affinity by post-SELEX modification and computer modeling. The substantial focus of this review is on the explanation of the principles of the electrochemical detection of antibiotics by aptasensors and on recent achievements in the development of electrochemical aptasensors. The current trends and problems in practical applications of aptasensors are also discussed.

Porous Cu-MOF nanostructures with anticancer properties prepared by a controllable ultrasound-assisted reverse micelle synthesis of Cu-MOF

The ultrasonic assisted reverse micelle method (UARM) was used to synthesize Cu-MOF from Cu(NO₃)₂·3H₂O and 2,6-pyridine dicarboxylic acid in a 1:1 molar proportion. It has been characterized using FT-IR, XRD, nitrogen adsorption analysis, SEM and TEM–EDX. The morphology of Cu-MOFs was spherical, with an average particle size distribution of less than 100 nm. Using BET analysis, the surface area of Cu-MOF was found to be 284.94 m²/g. The porous morphology of Cu-MOF was also suggested by SEM and TEM analyses. It has anticancer properties against MCF-7 breast cancer cells. Cytotoxicity testing was performed on MCF-7 breast cancer cells using the MTT cell viability assay, and cell proliferation and viability were found to be approximately 24% higher than the control.

Construction of manganese-based metal organic frameworks derived from aromatic dicarboxylic acids and application for the adsorption of iodine

In this work, we selected terephthalic acid or 2-amino-terephthalic acid as ligand, transition metal manganese salt as metal source under the solvothermal conditions to successfully construct two kinds of manganese-based metal-organic frameworks (Mn-MOFs): Mn3(BDC)3(H2O)2 (1) and Mn3(NH2-BDC)3(DMF)4 (2) (H2BDC = terephthalic acid; NH2-BDC = 2-amino terephthalic acid; DMF = N, N-dimethyl formamide). It was characterized by elemental analysis, IR spectrum, thermogravimetric analysis (TG), X-ray powder diffraction (PXRD) and UV-vis absorption spectrum. It was found that the packing structures of compounds 1 and 2 were constructed by the trinuclear Mn3O16 building block and exhibited different spatial structure: compound 1 was a three-dimensional structure, and 2 was a two-dimensional network structure. The iodine adsorption in cyclohexane solution properties of compounds 1 and 2 were investigated. Research results showed that the uncoordinated amino group in the structure of framework compounds has a great influence on the iodine adsorption capacity and compound 2 had good adsorption property and reusability.

N-Formylation of amines utilizing CO2 by a heterogeneous metal–organic framework supported single-site cobalt catalyst

Single-site cobalt-hydride supported on oxo-nodes of a porous aluminium metal–organic framework is a chemoselective and reusable catalyst for N-formylation of amines using CO2.

Synthesis of Al-Based Metal-Organic Framework in Water With Caffeic Acid Ligand and NaOH as Linker Sources With Highly Efficient Anticancer Treatment

In this study, novel nanostructures of aluminum base metal-organic framework (Al-MOF) samples were synthesized using a sustainable, non-toxic, and cost-effective green synthesis route. Satureja hortensis extract was used as an effective source of linker for the development of the Al-MOF structures. The Fourier-transformed infrared (FTIR) spectrum confirmed the presence of characterization bonds related to the Al-MOF nanostructures synthesized by the green synthesis route. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses revealed that the sample synthesized by Na2-CA was composed of multilayers, although it was agglomerated, but it had dispersed and occurred in spherical particles, indicating active organic matter. N2 adsorption/desorption isotherms demonstrated the significant porosity of the Al-MOF samples that facilitate the high potential of these nanostructures in medical applications. The anticancer treatment of Al-MOF samples was performed with different concentrations using the MTT standard method with untreated cancer cells for 24 and 48 h periods. The results exhibited the significant anticancer properties of Al-MOF samples developed in this study when compared with other MOF samples. Thus, the development of a novel Al-MOF and its application as a natural linker can influence the anticancer treatment of the samples. According to the results, the products developed in this study can be used in more applications such as biosensors, catalysts, and novel adsorbents.

Two transition complexes based on 1H-benzimidazole-5,6-dicarboxylic acid: Synthesis, structure and photocatalytic degradation of dyes

Metal-organic frameworks [Co(Hbidc)(H2O)2] (1) and [Mn(Hbidc)(H2O)] (2), with multidentate 1H-benzimidazole-5,6-dicarboxylic acid (H3bidc) ligand, have been synthesized under hydro/solvothermal conditions and structurally characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analysis revealed that the center Co atom of complex 1 is six-coordinated with three-dimensional supramolecular structure and center Mn of complex 2 is five-coordinated with exhibiting a 2D layered network. The photodegradation of Crystal violet dye and Methylene blue dye were studied firstly by complexes 1 and 2 as photocatalysts. Research result indicates that the degradation rate for complex 1 can reach 89.85% , 90.6% and that for complex 2 can reach 88.28% , 79.48% . At the same time, corresponding to photocatalytic kinetics was performed.

Post-synthetic modifications in porous organic polymers for biomedical and related applications

Porous organic polymers (POPs) are prepared by crosslinked polymerization of multidimensional rigid aromatic building blocks. Generally, POPs can be classified into crystalline covalent organic frameworks (COFs) and other poorly crystalline or amorphous porous polymers. Due to their remarkable intrinsic properties, such as high porosity, stability, tunability, and presence of numerous building blocks, several new POPs are being developed for application across various scientific fields. The essential sensitive functional groups needed for specific applications are not sustained under harsh POP preparation conditions. The recently developed post-synthetic modification (PSM) strategies for POPs have enabled their advanced applications that are otherwise restricted. Owing to the advanced PSM strategies POPs have experienced a blossoming resurgence with diverse functions, particularly in biomedical applications, such as bioimaging tools, drugs, enzymes, gene or protein delivery systems, phototherapy, and cancer therapy. This tutorial review focuses on the recently developed PSM strategies for POPs, especially for biomedical applications, and their future perspectives as promising bioapplicable materials.

Taguchi-Assisted Optimization Technique and Density Functional Theory for Green Synthesis of a Novel Cu-MOF Derived From Caffeic Acid and Its Anticancerious Activities

In this paper, we have reported an innovative greener method for developing copper-metal organic frameworks (Cu-MOFs) using caffeic acid (CA) as a linker extracted from Satureja hortensis using ultrasonic bath. The density functional theory is used to discuss the Cu-MOF-binding reaction mechanism. In order to achieve a discrepancy between the energy levels of the interactive precursor orbitals, the molecules have been optimized using the B3LYP/6-31G method. The Taguchi method was used to optimize the key parameters for the synthesis of Cu-MOF. FT-IR, XRD, nitrogen adsorption, and SEM analyses are used to characterize it. The adsorption/desorption and SEM analyses suggested that Cu-MOF has a larger surface area of 284.94 m2/g with high porosity. Cu-MOF has shown anticancer activities against the human breast cancer (MDA-MB-468) cell lines, and it could be a potent candidate for clinical applications.