Copper Metal-organic Framework Research Articles

Fabrication and application of copper metal–organic frameworks as nanocarriers for pH-responsive anticancer drug delivery

Fabrication and application of copper metal–organic frameworks as nanocarriers for pH-responsive anticancer drug delivery

A sensitive colorimetric hydrogen sulfide detection approach based on copper-metal-organic frameworks and a smartphone.

In this study, we demonstrate a colorimetric approach for the detection of hydrogen sulfide (H2S) in water samples with high sensitivity. Firstly, copper-metal-organic frameworks (Cu-MOFs) were synthesized by ultrasonic-assisted hydrothermal method, presenting a maximum absorption peak at 700 nm. It was found that Cu-MOFs could react with H2S to form a copper-sulfur complex along with a decrease of the absorption peak at 700 nm and a visible color change from blue to tan. Under the optimal reaction conditions, the absorption intensity at 700 nm was linear with H2S concentration in a range of 0.05-2 mM (R2 = 0.9928), providing a detection limit of 22 μM. Furthermore, the method was successfully applied to the detection of H2S in lake water samples with a recovery rate between 94.4% and 112.6%. In addition, a practical and portable device for on-site H2S detection was designed by using agarose hydrogels, and a simple colorimetric detection method based on a smartphone was developed. This analytical method showed good selectivity for H2S compared to other interfering substances, and the feasibility of the agarose hydrogel-based device was proved by the determination of H2S in real lake water samples.

Adsorption of CO2 on ZSM-5 and Cu-MOF at room temperature and low pressure conditions for Carbon Capture and Storage (CCS) application

The application of Carbon Capture and Storage (CCS) is viewed as a key strategy to achieve CO2 reduction targets. In capturing CO2 process, both adsorption and absorption are promising techniques for CO2 capture, but adsorption processes using solid adsorbents are the prevailing technique nowadays. In this study, the performance of the prepared adsorbents on the CO2 capture capability is investigated and compared. Zeolite (ZSM-5) and copper metal–organic framework (Cu-MOF) are selected as adsorbents because of high surface area and the excellent performance in the adsorption process. The performance of both adsorbents in CO2 adsorption is evaluated in a fabricated setup consists of a metal cylindrical vessel equipped with flow of pure CO2 gas from a cylindrical tank. The efficiency of the adsorption system was explored as a function of the experimental parameters: effect of adsorbent dosage (0–500 mg) and inlet flow pressure (0–1 bar). Based on the findings from FTIR, EDX and XRD analyses, the results suggested successful formation of ZSM-5 and Cu-MOF. The highest particle size distribution and area for ZSM-5 were in the range of 25–66 µm and 1.7–442 µm2, while 102–149 µm and 1.7–1400 µm2 for Cu-MOF, respectively. SEM images show an agglomeration and flaky particles. From the TGA analysis, ZSM-5 tends to remain stable compared to Cu-MOF where lacks the ability to retain its framework at temperature above 400 °C. The optimum conditions obtained in the adsorption process for both adsorbents were 200 mg adsorbent dosage and 1 bar inlet pressure. Based on the results, ZSM-5 shows the best performance with high CO2 adsorption capacity as compared to Cu-MOF at the low pressure system. Under the optimum condition, 800 and 1000 mg/g adsorption capacity of Cu-MOF and ZSM-5 were achieved within 50 min of reaction to adsorb CO2.

Copper metal organic framework as natural oxidase mimic for effective killing of Gram-negative and Gram-positive bacteria.

Nanozymes have been widely studied as substitutes for natural enzymes. However, the delicacy of their structures and their unclear catalytic sites make it difficult to maintain their structural robustness and catalytic durability. By mimicking active catalytic sites of natural enzymes and combining them with distinct channels of metal organic frameworks (MOFs), an active copper mimetic oxidase enzyme (Cu-MOF) was designed and synthesized with good structure and clear catalytic sites for improvement in catalytic activity. The Cu-MOFs showed excellent oxidase-like activity with a low Km of 1.09 mM and exogenous ROS generation capacity. The Cu-MOFs exhibited antibacterial efficacy at a low concentration of 12.5 μg mL-1 by an oxidative stress response. These Cu-MOFs with their simple design and effective oxidase mimicking show attractive application prospects in the field of antibacterial and enzyme catalysis.

Highly efficient multi-site synergistic catalysis of a polyoxovanadate-based metal–organic framework for benzylic C–H bond oxidation

Multi-active site synergy in a polyoxovanadate-based mixed-valence copper metal–organic framework for efficient catalysis of C–H bond oxidation of benzylic compounds.

One-pot synthesis of porous crystal structured nanosponge-like pristine copper metal–organic framework for hybrid supercapacitor application

A porous crystal structured nanosponge-like pristine Cu-MOF is synthesized using a facile one-pot synthesis method. It is adopted as an anode material to fabricate a aqueous hybrid supercapacitor device with a long lifespan and high energy density.

A novel copper metal–organic framework catalyst for the highly efficient conversion of CO2 with propargylic amines

A novel copper metal–organic framework catalyst for the highly efficient conversion of carbon dioxide with propargylic amines to 2-oxazolidinones.

Ingenious Design of One Mixed-Valence Dual-Net Copper Metal-Organic Framework for Deriving Cu2o/Cuo Heterojunction with Highly Electrocatalytic Performances from No3- to Nh3

Ingenious Design of One Mixed-Valence Dual-Net Copper Metal-Organic Framework for Deriving Cu2o/Cuo Heterojunction with Highly Electrocatalytic Performances from No3- to Nh3

Syntheses of two copper metal-organic frameworks with tri(1,2,4-triazole) and biscarboxylate and graphene oxide composites for decomposition of dye by visible-light driven and ultrasonic assisted

Two crystalline and nano-sized new Cu(II) MOFs {[Cu(ttpa)(1,3-bdc)(H2O)]·CH3OH}n (Cu(ttpa)-1) and {[Cu(ttpa)(mip)(H2O)]•2H2O} (Cu(ttpa)-2) were prepared and characterized (ttpa ​= ​tris(4-(1,2,4-triazol-1-yl)phenyl)amine, 1,3-bdc ​= ​1,3-benzenedicarboxylate, mip ​= ​5-methyl-isophthalate) by hydrothermal method and sonochemical method. Cu(ttpa)-1 and Cu(ttpa)-2 exhibited the 2D network with point symbol {44⋅62}{44⋅62}. The effect of sonicated time, power, frequency and temperature on the morphology of nano-sized Cu(ttpa)-1 and Cu(ttpa)-2 were studied. The MOFs@10%GO composites (GO ​= ​graphite oxide) exhibited the highest activities. The catalytic decomposition of methylene blue (MB) using Cu(ttpa)-1, Cu(ttpa)-2, Cu(ttpa)-1@GO and Cu(ttpa)-2@GO composites were examined under visible light and ultrasound. Cu(ttpa)-1, Cu(ttpa)-2, Cu(ttpa)-1@GO and Cu(ttpa)-2@GO exhibited high degradation efficiency. The degradation efficiency of MB for Cu(ttpa)-1@GO was 91.2% at pH ​= ​8 after 15 ​min visible light irradiation and the photocatalytic rate constant (k) was 0.1165 ​min−1. The •OH hydroxyl radicals and •O2- superoxide were the main active matters for catalyst Cu(ttpa)-1@GO and Cu(ttpa)-2@GO in the degradation of MB. Cu(ttpa)-1@GO has the higher catalytic efficiency of degradation of MB than most of MOFs, MOFs composites and inorganic photocatalysts. Cu(ttpa)-1@GO is the good photocatalytic material.

Copper(II)-MOF Containing Glutarate and 4,4′-Azopyridine and Its Antifungal Activity

Antifungal activities of MOFs (metal organic frameworks) have been demonstrated in studies, and improvement in efficiency of fungal inactivation is a critical issue in the application of MOFs. In this study, we employed 4,4′-azopyridine (AZPY) in the construction of MOF to improve its antifungal activity. Three-dimensional (3D) copper metal organic framework containing glutarate (Glu) and AZPY (Cu(AZPY)-MOF) was synthesized by a solvothermal reaction. Glutarates bridge Cu2 dinuclear units to form two-dimensional (2D) layers, and these layers are connected by AZPY to form a 3D framework. When spores of two fungi, Candida albicans and Aspergillus niger, were treated with Cu(AZPY)-MOF for one day, number of CFU (colony forming unit) was continuously reduced over treated MOF concentrations, and maximum 2.3 and 2.5 log10CFU reductions (approximately 99% reduction) were observed in C. albicans and A. niger, respectively. Small amounts of CuII ions and AZPY released from Cu(AZPY)-MOF were not critical for fungal inactivation. Our results indicate that the level of antifungal activity of Cu(AZPY)-MOF is greater than that of Cu-MOF without AZPY constructed in our previous study, and intercalation of AZPY is able to improve the antifungal activity of Cu(AZPY)-MOF.

Two-dimensional copper metal-organic frameworks as antibacterial agents for biofilm treatment

Two-dimensional copper metal-organic frameworks as antibacterial agents for biofilm treatment

Two birds with one stone: Copper metal-organic framework as a carrier of disulfiram prodrug for cancer therapy

Disulfiram (DSF) has a copper (II)-potentiated anticancer activity in various cancers. Synchronous delivery of DSF and cupric ions to tumor tissues is challenging but holds great potential in improving antitumor outcomes and promoting clinical translation. Herein, we reported a disulfiram prodrug (DQ)-loaded and glucose oxidase (GOD) conjugated copper (II)-based nanoscale metal–organic framework (MOF), MPDG, for tumor-specific, enhanced chemo-chemodynamic therapy. Copper MOF, MOF-199, played a dual role of drug nanocarrier of DQ and copper ion reservoir for sufficient generation of copper (II) diethylthiocarbamate (Cu(DTC)2), a complex of DSF and Cu2+. GOD improved the stability of Cu(II) nano-depot and enabled catalytic generation of H2O2 in response to high concentration of glucose in cancer cells. The catalytically generating and endogenous H2O2 boosted the activation of encapsulated H2O2-activatable prodrug DQ to generate highly cytotoxic Cu(CDTC)2 in situ for tumor-specific chemotherapy. Meanwhile, the elevated H2O2 significantly augmented the production of OH for enhanced chemodynamic therapy. The self-activated amplified chemo-chemodynamic therapy nanosystem led to a significantly enhanced inhibition of 4T1 murine breast cancer cells (half inhibitory concentration reduced from 5 μg/mL to 0.8 μg/mL) in the presence of glucose. The in vivo study verified that MPDG showed the highest tumor inhibition rate of 86.2% and negligible toxicity to main organs. Overall, this study provides a novel disulfiram prodrug/Cu2+ co-delivery strategy for enhanced and selective cancer treatment.

Adsorption of Carbon Dioxide by Metal Organic Framework for Indoor Air Quality Enhancement

Air pollution has become a severe environmental issue among millions of people around the globe. However, the risk of exposure to indoor air pollution is much higher than outdoor air pollution. The most effective way to improve indoor air quality (IAQ) by reducing the indoor CO2 content is by capturing and storing. There are several types of adsorbents used to capture CO2, namely physical adsorbents and chemical adsorbents. Metal-Organic Framework (MOF) is one of the recent interests arising physical adsorbents which possesses high adsorption capability. In this study, MOFs fabricated with different metals and organic ligands were used to evaluate their performance in CO2 adsorption under an enclosed office space. Magnesium, chromium, and copper metals were used as the main element in the MOF fabrication coupled with trimesic acid as an organic ligand. The MOFs’ morphologies generally illustrated that magnesium MOF exhibited a dispersed nanorod flask crystal, chromium MOF showed agglomeration crystal, whereas fine crystal rod was observed in copper MOF. The elemental analysis from EDX and XRD confirmed that the metals were successfully embedded with the organic ligand, which is similar to the literature studies. The CO2 gas adsorption study suggested that magnesium MOF fabricated with trimesic acid possess superior CO2 adsorption capability as the recorded CO2 concentration reduced from 960 ± 73 ppm to 895 ± 57 under 2 hours continuous sampling time. The CO2 adsorption study reveals that the magnesium MOF with trimesic acid ligand yields a promising result on indoor CO2 concentration reduction. This result suggested that the MOF possesses a great potential to be applied in the indoor air quality enhancement with the integration to the existing air purification and/or filtration system.

In situ synthesis of copper metal-organic framework on paper-based device for dual-mode detection of volatile sulfur compounds in exhaled breath

Volatile sulfur compounds (VSCs) are considered as indicators of halitosis and precursors of periodontal diseases. Trace VSCs determination in-breath can provide noninvasive data for clinical diagnostics. In this work, a dual-mode colorimetric/ chemiluminescent (CL) paper-based device with a copper metal-organic framework (Cu-MOF) was developed for trace VSCs detection in exhaled breath. The Cu-MOF with 2,4,6-tris(4-carboxyphenyl)− 1,3,5-triazine (TATB) as a ligand was in situ synthesized on a paper surface by the solvothermal method. The porous Cu-TATB served as a gaseous confinement cavity to selectively capture and adsorb VSCs. When Cu-TATB reacted with VSCs, significant and sensitive color changes can be observed from aqua blue to greenish-brown. Also, the Cu-TATB had an excellent catalytic effect on the luminol-H2O2 CL system. The CL intensity was inhibited by VSCs because of sulfur in VSCs reacting with copper active sites in Cu-TATB to form CuS. In this way, dual-mode detection methods for VSCs in breath were established with limits of detection (LOD) of 0.2 µM for colorimetry and 8 nM for CL. This portable, low-cost and stable paper-based sensor realizes accurate and reproducible signals read-out and shows potential feasibility as a prospect sensor platform for exhaled breath analysis.

A novel, eco-friendly multi-walled carbon nanotubes functionalized copper metal-organic framework for ultrasensitive potentiometric detection of cadmium ions

Designing a simple and on-site detection technique for Cd2+ is highly demanding. In the current study, an electrochemical sensor based on multi-walled carbon nanotubes (CNTs) and copper metal-organic framework (Cu-MOF) was synthesized via one-pot hydrothermal reaction for the rapid and economical monitoring of the Cd2+ level. The structure, morphology and physical properties of prepared CNT-Cu-MOF were characterized by different physicochemical techniques. The surface of the glassy carbon electrode was modified with CNT-Cu-MOF to detect Cd2+ in 01 M phosphate Buffer. The detection limit was found to be 0.275 nM (S/N = 3), with linear calibration curves ranging from 0.2 to 10 μM. Furthermore, the developed electrochemical sensor demonstrated excellent selectivity, stability, and repeatability. The recovery of the CNT-Cu-MOF is found to be 100.4% in a real-time sample of tap-water. The well-designed sensor employs a promising approach for on-site monitoring of Cd2+ in tap water.

Visible-light-driven and ultrasonic-assisted copper metal-organic frameworks and graphene oxide nanocomposite for decolorization of dyes

The crystalline and nano-sized {[Cu(tipe)(H2O)](2,2′-bpdc)·11H2O·DMF}n (1·11H2O·DMF or Cu-tipe) (tipe ​= ​1,1,2,2-tetrakis (imidazole-1-yl)phenyl)ethylene, 2,2′-bpdc ​= ​2,2′-biphenyldicarboxylate) were synthesized and structural analysis by X-ray diffraction, scanning electron microscopy, optical band gaps, photoluminescence and thermal stability. Cu-tipe and graphene oxide (GO) nanocomposite (Cu-tipe/GO) was synthesized with sonochemical method and characterized. Cu-tipe exhibits a (4,4)-coordinated 2D network showing the point symbol {44·62}{44·62}. The photocatalytic and sonocatalytic decolorization of methylene blue (MB), methyl violet (MV), rhodamine B (RhB) under visible light and ultrasound irradiation showed that the catalytic efficiencies of decolorization organic dyes for Cu-tipe/GO composite are higher than these of most of MOF and MOF composite. Crystalline and nano-sized Cu-tipe also showed high decolization efficiencies. The radicals trapping experiments were carried out to study the active species and the degradation mechanism was proposed.

Synthesis of Copper Metal Organic Framework Based on Schiff Base Tricarboxylate Ligand for Highly Selective and Sensitive Detection of 2,4,6-Trinitrophenol in Aqueous Medium.

By using Schiff base tricarboxylate ligand 5-(4-carboxybenzylideneamino)isophthalic acid (H3CIP), a new imine functionalized copper metal organic framework (MOF) has been synthesized solvothermally. It was fully characterized by Fourier Transform Infrared (FTIR) Spectroscopy, Powder X-Ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and elemental mapping techniques. The as-synthesized MOF has been utilized as fluorescent probe for detection of nitro aromatic explosives (NAEs). The results show that the copper MOF can be developed into highly selective and sensitive sensor for detection of TNP in the aqueous medium via the "turn-off" quenching response. The linear fitting of the Stern-Volmer plot for TNP offered large quenching constant of 1.07 × 104 M-1 for Cu-MOF indicating the high sensitivity of the sensing process. Outstanding sensitivity of prepared material towards TNP detection was further validated by the low detection limit of 80 ppb (0.35 µM). The detailed mechanistic studies for their mode of action and density functional theory (DFT) calculations reveals that photo-induced electron transfer (PET) and fluorescence resonance energy transfer (FRET) processes, as well as electrostatic interactions (i.e. H-bonding) are the key factors for the turn-off response toward TNP by this fluorescent sensor. Thus, this new LMOF owing to their high water stability and remarkable functional features are potential candidates which can be developed into selective and sensitive TNP detection devices.

Enhanced Catalytic Activity for CO Oxidation by Highly Active Pd Nanoparticles Supported on Reduced Graphene Oxide /Copper Metal Organic Framework

As a result of the increase in industrial activities and the extensive use of automobiles, air pollutants, especially carbon monoxide, reach the alarm level. The removal of carbon monoxide through oxidation is still one of the best tactics so far. Therefore, looking for an active and durable catalyst is considered the key factor for improving the oxidation process. In this work, Pd nanoparticles (1.0, 3.0 and 5.0 wt.%) were supported onto reduced graphene oxide / copper metal organic framework nanocomposite (rGO@Cu-BTC) through one pot solvothermal synthesis method. The catalysts were thoroughly characterized by state-of-the-art techniques such as XPS, SEM, TEM, XRD, N2 physisorption, and FT-IR. The results revealed that the Pd nanoparticles were exceptionally dispersed on rGO@Cu-BTC nanocomposite surface and the Cu-BTC crystals showed excellent octahedral structure with smooth edges as indicated SEM images. The results revealed that 3.0 wt. % Pd/rGO@Cu-BTC acts as an excellent catalyst in the CO oxidation as indicated by T50 and T100 values of 71 and 82 °C, respectively. Additionally, the results showed that rGO has a vital role in the dispersion of Pd NPs on the catalyst surface as well as the presence of surface oxygen groups, which yields higher catalytic activity compared with the catalyst without rGO.

An efficient chemiluminescence system based on mimic CuMOF/Co3O4 nanoparticles composite for the measurement of glucose and cholesterol

The development of novel non-enzyme mimics for (bio)sensing applications is of great practical importance. Herein, an efficient chemiluminescence (CL) system is presented according to the significant mimetic behavior of the copper metal-organic framework decorated with cobalt oxide nanoparticles (Co3O4@CuMOF). The catalytic activity of nanocomposite was proved by its strengthening effect on the CL emission of rhodamine B (RB)-hydrogen peroxide (H2O2) reaction. More documents were also obtained using colorimetric and fluorometric peroxidase substrates. The presence of Cu and Co in the Co3O4@CuMOF structure, as well as the high porosity and great surface area of the obtained composite, was responsible for the observed synergetic catalytic activity. The Michaelis-Menten constant (Km) for the composite (0.108 mM) was remarkably lower than that of pristine CuMOF and Co3O4 NPs, illustrating its superior affinity towards H2O2. A linear correlation was found between the CL intensity and H2O2 concentration in the extensive range of 1–250 nM, with a detection limit (3S) of 0.244 nM. Furthermore, the developed system was exploited as a reliable sensing device for individual measurement of cholesterol and glucose after their enzymatic oxidations. The obtained data verified the high sensitivity and selectivity of the probe, which could be linked to the presence of high-performance Co3O4@CuMOF and the accompanying enzymes, respectively. The designed method was appropriately applied to measure cholesterol and glucose levels in human serum samples, and its accuracy was validated by analyzing the standard materials.

Preparation of CuO@Mesoporous SiO2 Via Calcining Nanocasted Metal Organic Frameworks (MOFs) for Styrene Oxidation Reaction

A mesoporous silica bearing uniformly distributed copper oxide nanoparticles (CuO@mesoporous SiO2) was prepared through silica nanocasting copper metal organic frameworks (MOFs) followed by calcination. The nanocasting filled the micropores of MOFs with silica and then, the calcination removed the organic linker in MOFs and converted copper metal ions into CuO particles, resulting in the CuO@mesoporous SiO2 architecture. The characterization results indicated that the final product basically maintained the original MOF morphology and the mesoporous silica effectively prevented the aggregation of nanoparticles. In addition, the CuO@mesoporous SiO2 exhibited a superior activity for catalyzing the oxidation of styrene, which could be attributed to the fact that the dispersed CuO particles in mesoporous silica provided more accessible catalytic sites and better stability. This work provides a new strategy to prepare nanoparticles@mesoporous silica with adjustable morphology structure, which has a promising potential in the field of heterogeneous catalysis.