Cu-metal Organic Framework Research Articles

Conducting polymer functionalized Cu-metal organic framework-based electrochemical immunosensor for rapid and sensitive quantitation of Escherichia coli O157:H7.

Escherichia coli (E. coli) O157:H7 is an important food-borne pathogen that can cause hemorrhagic diarrhea and enteritis in humans and animals. Realizing the rapid quantitation of E. coli O157:H7 is of great significance for the guarantee of food safety and disease control. In this study, an electrochemical immunosensing technique based on a functionalized composite of Cu-metal organic framework (Cu-MOF) and poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT:PSS) is developed, achieving rapid and sensitive quantitation of E. coli O157:H7 in food and clinical feces samples. The organic functionalization of Cu-MOF significantly improves the interface conductivity to facilitate electron transfer and provides the sulfonic groups (-SO3H) to conjugate bio-recognizing elements for target determination. The immunosensor delivers a linear detection range of 3 × 102 ~ 3 × 108cfu/mL, a low limit of detection (LOD) of 7.4cfu/mL, and a short analysistime of 40min. In addition, it does not show any cross-reactivity with other common pathogens and exhibits high repeatability with relative standard deviations (RSDs) all lower than 2.09%, providing a promising approach for warranting food safety and control of E. coli O157:H7 disease.

Facile preparation of cubic metal organic framework sensor: Kinetics, mechanism analysis and sensitive detection of dopamine

Dopamine (DA) is one of the typical neurotransmitters, which plays an important role in early prevention of neurological diseases and clinical research. Rapid and sensitive detection of dopamine is crucial. In this work, a series Cu-metal organic framework material (Cu-MOF) with different raw material ratios were prepared by a one-step simple precipitation method. The as-prepared materials were characterized by scanning electron microscopy (SEM), High Resolution Transmission Electron Microscope (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FT-IR) techniques. The differential pulse voltammetry (DPV), cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS) were applied for electrochemical characterization. The Cu-MOF-3 modification on the surface of glassy carbon electrodes (GCE) showed the strongest electrochemical signal and biggest peak current, which was superior to that of bare electrode and other prepared MOFs electrodes. The electrochemical reaction kinetics were investigated in detail, and the possible mechanism was proposed. Under optimized conditions, the enhanced peak currents represented the excellent analytical performance of detection of DA in the range of 10–100 μM, as well as good interference resistance and reproducibility. To further validate its possible application, the present electrochemical sensor was successfully applied to determine trace amount of DA with satisfactory recovery results (>99.5 %) in water sample. This work provides a simple and environment-friendly analysis method in DA detection, suggesting it as a promising low-cost, reliable platform for the DA detection application.

In situ growth of self-supported CuO nanorods from Cu-MOFs for glucose sensing and elucidation of the sensing mechanism.

Herein, we present a simple and mild method to in situ prepare CuO nanostructures for non-enzymatic glucose sensing. A Cu-metal organic framework (Cu-MOF) precursor was first directly grown on a pencil lead electrode with 3D graphene-like surfaces (EPLE) and then in situ transformed into CuO nanorods. The CuO nanorod-modified EPLE (CuO/EPLE) shows high sensitivity (1138.32 μA mM-1 cm-2), fast response time (1.5 s) and low detection limit (0.11 μM) for glucose oxidation. It has been found that NaOH promoted the generation of ˙OH groups and Cu(III) on the CuO surface, which then facilitated the electrochemical oxidation of glucose. Signals characteristic of hydroxyl and carbon-centered radical adducts were detected by EPR. Furthermore, the CuO/EPLE sensor also shows good accuracy in glucose determination in human serum samples.

Non-enzymatic amperometric glucose sensing by novel Cu-MOF synthesized at room temperature

Cu-metal–organic framework (Cu-MOF) derived from 1,2,4,5-benzene tetracarboxylic acid (H4BTC) has been synthesized through a quick and soft-template synthesis at room temperature.

Gelatin/carrageenan-based smart packaging film integrated with Cu-metal organic framework for freshness monitoring and shelf-life extension of shrimp

A gelatin/carrageenan (Gel/Car) based antibacterial and pH-responsive intelligent film was developed by incorporating a Cu-metal organic framework (Cu-MOF) and anthocyanins from red cabbage (Brassica oleracea). Cu-MOF and anthocyanin were mixed compatibly with the polymer matrix to form a dense, flexible, and strong film. The film incorporated with 3 wt% Cu-MOF displayed excellent UV-barrier ability (98.5% in the UV-A and 99.9% in the UV-B), strong antioxidant efficacy against ABTS (100%), and DPPH (100%) and exhibited strong antibacterial activity to completely stop the growth of Gram-positive and Gram-negative bacteria after 3 h of incubation. In addition, the film exhibited pH-dependent color change under various pH conditions (pH 2 to 12), and freshness monitoring tests of shrimp demonstrated a qualitative and quantitative color change of the film (decreasing the redness, a-value, from 24.5 to 3.7). In packaging experiments using shrimp, this packaging film delayed the quality change rate of foods during storage and extended the shelf life of these foods. The gelatin/carrageenan-based multifunctional film combined with a Cu-metal organic framework is expected to help visualize food changes before consumption, extend processed foods' shelf life, and significantly reduce food waste problems.

Efficient visible light-induced photodegradation of industrial lignin using silver-CuO catalysts derived from Cu-metal organic framework

Efficient visible light-induced photodegradation of industrial lignin using silver-CuO catalysts derived from Cu-metal organic framework

Detection of di(2-ethylhexyl) phthalate in edible vegetable oils using a sensitive aptasensor based on carbon nanomaterials and copper metal-organic framework

In this work, we designed a simple, disposable, highly sensitive electrochemical aptasensor to detect di(2-ethylhexyl) phthalate (DEHP) in edible vegetable oils. The aptasensor was created by decorating polyaniline multi-walled carbon nanotubes (PANI-MWCNTs), Cu metal-organic framework (CuMOF), and gold nanoparticles (AuNPs) on a screen printing carbon electrode (SPCE). With its large surface area, CuMOF modified the electrode by improving the adhesion rate of gold nanoparticles, thereby improving the detection limit of the sensor. The distinct peak in the square wave voltammetry (SWV) was used to measure DEHP. The sensor had high stability, excellent repeatability, reproducibility, and specificity, with a wide linear range (0.1–100 ng/mL) and a low detection limit (0.03 ng/mL). When the aptasensor was used to analyze the DEHP content in edible vegetable oils, the recovery rate was between 95.11 % and 98.29 %, and the results were consistent with the GC-MS measurements.

Cu-Metal Organic Framework Derived Multilevel Hierarchy (Cu/CuxO@NC) as a Bifunctional Electrode for High-Performance Supercapacitors and Oxygen Evolution Reaction.

The development of a MOFs-derived multilevel hierarchy in a single step still remains a challenging task. Herein, we have synthesized novel Cu-MOF via a slow diffusion method at ambient temperature and further utilized it as a precursor source for MOF-derived multilevel hierarchy (Cu/CuxO@NC, x = 1 and 2). This studies suggest that the organic ligands served as a source of an N-doped carbon matrix encapsulated with metal oxide nanoparticles which were confirmed by various characterization techniques; further BET analysis reveals a surface area of 178.46 m2/g. The synthesized multilevel hierarchy was utilized as an electro-active material in a supercapacitor that achieved a specific capacitance of 546.6 F g-1 at a current density of 1 A g-1 with a higher cyclic retention of 91.81% after 10 000 GCD cycles. Furthermore, the ASC device was fabricated using Cu/CuxO@NC as the positive electrode and carbon black as the negative electrode and utilized to enlighten the commercially available LED bulb. The fabricated ASC device was further employed for a two-electrode study which achieved a specific capacitance of 68 F g-1 along with a comparable energy density of 13.6 Wh kg-1. Furthermore, the electrode material was also explored for the oxygen evolution reaction (OER) in an alkaline medium with a low overpotential of 170 mV along with a Tafel slope of 95 mV dec-1 having long-term stability. The MOF-derived material has high durability, chemical stability, and efficient electrochemical performance. This work provides some new thoughts for the design and preparation of a multilevel hierarchy (Cu/CuxO@NC) via a single precursor source in a single step and explored multifunctional applications in energy storage and an energy conversion system.

CO2, CH4, and H2 Adsorption Performance of the Metal–Organic Framework HKUST-1 by Modified Synthesis Strategies

High-pressure adsorption of CO2, H2, and CH4 has several applications, including CO2 capture, methane, and hydrogen storage. The performance ultimately depends on the adsorbent design. Herein, we report a comparative assessment of a Cu-metal–organic framework (MOF) (HKUST-1) by conventional hydrothermal synthesis and its modified analogues, HKUST-N with NH4OH and HKUST-Ca with Ca(NO3)2, for CO2, CH4, and H2 adsorption. The materials showed high CO2 (12 mol/Kg), CH4 (2.5–4 mol/Kg), and H2 (0.4–0.8 mol/Kg) capacities at 50 bar. Owing to different synthesis strategies, the differences in surface area, pore size distribution, morphology, and the presence of calcium species in HKUST-Ca considerably impacted CH4 and H2 adsorption, leading to considerable differences in selectivities for various gas mixtures. This work establishes a clear correlation of subtle modifications in synthesis strategies of the MOF HKUST-1 on its morphological characteristics and CO2, CH4, and H2 adsorption performance.

A dual-ratiometric electrochemical sensor based on Cu/N-doped porous carbon derived from Cu-metal organic framework for acetaminophen determination

Ratiometric electrochemical sensors with internal correction function have received extensive attention due to their good resistance to complex factors. Herein, a dual-ratiometric electrochemical sensor was fabricated for the determination of acetaminophen (AP) based on glass carbon electrode (GCE) modified by methylene blue /Cu/N-doped porous carbon (MB/Cu/N-C) composite. The Cu/N-C derived from the calcination of Cu based metal–organic framework not only had good electrochemical performance, but also provided a redox signal as an internal reference and plenty of attachment sites for another reference molecules-MB. The electrochemical results displayed that MB/Cu/N-C/GCE had three peaks at 0.34, 0.04, and −0.29 V when AP was present, which came from the electro-oxidation of AP, Cu/N-C, and MB, respectively. Two ratiometric signals, namely, IAP/IMB and IAP/ICu/N-C, were utilized to the detection of AP. The IAP/IMB and IAP/ICu/N-C were linearly correlated with the AP concentrations in the range of 0.5 to 150.0 μM and the detection limits were determined to be 0.3 μM and 0.4 μM, respectively. Meanwhile, this sensor was utilized to determinate AP in pharmaceutical tablet samples with good recoveries, which displayed the great potential of MB/Cu/N-C/GCE in clinical applications.

Preparation of Chitosan Modified Cu-Metal–Organic Framework Antibacterial Microspheres and Their Application in Adsorption of Cr(VI) from Aqueous Solution

Preparation of Chitosan Modified Cu-Metal–Organic Framework Antibacterial Microspheres and Their Application in Adsorption of Cr(VI) from Aqueous Solution

Metal-organic framework-derived Cu nanoparticle binder-free monolithic electrodes with multiple support structures for electrocatalytic nitrate reduction to ammonia.

Electrocatalytic nitrate reduction to ammonia, which removes nitrates from aquatic ecosystems, is a potential alternative to the classical Haber-Bosch process. Nevertheless, the selectivity of ammonia is often affected by the toxic by-product nitrite. Here, the polyhedral-supported Cu nanoparticle binder-free monolithic electrode (Cu-BTC-Cu) is synthesized by the in situ electroreduction of Cu metal-organic framework (Cu-MOF) precursors. The Cu-BTC-Cu displays a high ammonia yield of 4.00 mg h-1 cm-2cat and a faradaic efficiency of 83.8% in 0.05 M K2SO4 (pH = 7), greatly outperforming the rod-supported (Cu-BTEC-Cu) and unsupported (Cu-BDC-Cu) Cu nanoparticle monolithic electrodes. Impressively, the Cu-BTC-Cu can inhibit significantly the release of by-product NO2- and present favourable stability after 10 consecutive cycles. These preeminent properties can be attributed to the polyhedral structure, which enables better dispersion of Cu nanoparticles and brings more active sites. Moreover, the reaction mechanism of Cu-BTC-Cu is analysed by electrochemical in situ characterization and several key intermediates are captured. This work provides new insights into the modification of the electrocatalytic nitrate reduction activity of Cu-based catalysts and ideas for the design of high-efficiency electrodes.

A Mechanochemically Active Metal‐Organic Framework (MOF) Based on Cu‐Bis‐NHC‐Linkers: Synthesis and Mechano‐Catalytic Activation

Mechanochemical Activation In article 2200207, Wolfgang H. Binder and co-workers demonstrate mechanochemical activation of a Cu-metalorganic framework (MOF), in turn triggering CuAAC of a model reaction system. Activation of the MOF generates free coordination-sites to generate spatial proximity between the azide/alkyne and thus inducing the “click”-reaction.

Electrochemical sensor based on molecularly imprinted polymer coating on metal–organic frameworks for the selective and sensitive determination of carbendazim

In this work, a graphite-epoxy (GE) electrode was modified with molecularly imprinted polymer (MIP) and Cu-metal–organic framework (Cu-MOF; Cu(II)/benzene-1,3,5-tricarboxylic). The novel modified electrode was proposed to determine carbendazim (CBZ) in some fruits. [Cu3(BTC)2(H2O)3]n (HKUST-1) was synthesis via solvothermal method. Carbendazim (template), methacrylic acid (functional monomer), and ethylene glycol dimethyacrylate (cross-linker) were used for the synthesis of MIP on the surface of HKUST-1. The HKUST-1@MIP were characterized by fourier transform infrared spectroscopy, X-ray diffraction, and field-emission scanning electron microscopy. The electrochemical behavior of HKUST-1@MIP-GE sensor was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). Under optimum conditions the proposed electrode provided a linear concentration range of 0.01–50.00 µmolL−1, with a detection limit of 2 nmolL−1. The RSD% for six successive determinations of 0.80 and 25.00 µmol L-1 CBZ were 2.4% and 2.1%, respectively.

Synthesis and characterization of CoFe2O4/SiO2/Cu-MOF for degradation of methylene blue through catalytic sono-Fenton-like reaction

• Synthesis of three-metallic catalyst with porous structure. • Synergic effect between the transition metals led to high catalytic activity. • Methylene blue was degraded through ultrasound-assisted Fenton-like reactions. • 98% of methylene blue was degraded in just 30 min. Successful catalytic degradation of pollutant molecules in wastewater streams has received tremendous attention in the last decade. Herein, we report the synthesis and characterization of a Fenton-like catalyst nanocomposite including CoFe 2 O 4 magnetic nanoparticles, porous silica and Cu-metal–organic framework (Cu-MOF) via a multi-step self-assembly method. For this purpose, CoFe 2 O 4 /SiO 2 magnetic nanostructure was synthesized by sol–gel method and then functionalized by glutaric anhydride and 3-(triethoxysilyl)propylamine. Subsequently, a nanoporous Cu-MOF framework was grown on the surface of nanoparticles to gain CoFe 2 O 4 /SiO 2 /Cu-MOF nanostructure. This unique nanocomposite offers various functional sites for the successful catalytic treatment of wastewater, confirmed by different analytical characterization techniques. The as-designed nanocomposite catalyst showed a porous structure with 27 g/m 2 surface area. The as-synthesized nanocomposite was used to degrade methylene blue in its aqueous solution as a model wastewater sample through a sono-Fenton-like reaction approach. The results showed that almost all (∼98%) of the methylene blue molecules were degraded in the model wastewater sample an hour. Additionally, we analyzed the catalytic kinetic data by several mathematical models. The analysis revealed that the catalytic process follows a pseudo-second-order kinetic model, indicating that the removal of dye took place dominantly through the multi-site interactions, thanks to different active sites on the surface of the as-synthesized nanocomposite. This study shows that the proposed nanoporous magnetic MOF nanostructure has a great potential to be used as a catalyst for environmental applications.

Integration of ultrafine CuO nanoparticles with two-dimensional MOFs for enhanced electrochemical CO2 reduction to ethylene

To facilitate the electrochemical CO2 reduction (ECR) to fuels and valuable chemicals, the development of active, low cost, and selective catalysts is crucial. We report a novel ECR catalyst consisting of CuO nanoparticles with sizes ranging from 1.4 to 3.3 nm anchored on Cu metal-organic framework (Cu-MOF) nanosheets obtained through a one-step facile solvothermal method. The nanocomposites provide multiple sites for efficient ambient ECR, delivering an average C2H4 faradaic efficiency (FE) of ~50.0% at –1.1 V (referred to the reversible hydrogen electrode) in 0.1 mol/L aqueous KHCO3 using a two-compartment cell, in stark contrast to a C2H4 FE of 25.5% and 37.6% over individual CuO and Cu-MOF respectively, also surpassing most newly reported Cu-based materials under similar cathodic voltages. The C2H4 FE remains at over 45.0% even after 10.0 h of successive polarization. Also, a ~7.0 mA cm−2 C2H4 partial geometric current density and 27.7% half-cell C2H4 power conversion efficiency are achieved. The good electrocatalytic performance can be attributed to the interface between CuO and Cu-MOF, with accessible metallic moieties and the unique two-dimensional structure of the Cu-MOF enhancing the adsorption and activation of CO2 molecules. This finding offers a simple avenue to upgrading CO2 to value-added hydrocarbons by rational design of MOF-based composites.

Construction of Novel Nanocomposites (Cu-MOF/GOD@HA) for Chemodynamic Therapy.

The emerging chemodynamic therapy (CDT) has received an extensive attention in recent years. However, the efficiency of CDT is influenced due to the limitation of H2O2 in tumor. In this study, we designed and synthesized a novel core-shell nanostructure, Cu-metal organic framework (Cu-MOF)/glucose oxidase (GOD)@hyaluronic acid (HA) (Cu-MOF/GOD@HA) for the purpose of improving CDT efficacy by increasing H2O2 concentration and cancer cell targeting. In this design, Cu-MOF act as a CDT agent and GOD carrier. Cu(II) in Cu-MOF are reduced to Cu(I) by GSH to obtain Cu(I)-MOF while GSH is depleted. The depletion of GSH reinforces the concentration of H2O2 in tumor to improve the efficiency of CDT. The resultant Cu(I)-MOF catalyze H2O2 to generate hydroxyl radicals (·OH) for CDT. GOD can catalyze glucose (Glu) to supply H2O2 for CDT enhancement. HA act as a targeting molecule to improve the targeting ability of Cu-MOF/GOD@HA to the tumor cells. In addition, after loading with GOD and coating with HA, the proportion of Cu(I) in Cu-MOF/GOD@HA is increased compared with the proportion of Cu(I) in Cu-MOF. This phenomenon may shorten the reactive time from Cu-MOF to Cu(I)-MOF. The CDT enhancement as a result of GOD and HA effects in Cu-MOF/GOD@HA was evidenced by in vitro cell and in vivo animal studies.

Electrochemical Deposition of Cu Metal-Organic Framework Films for the Dual Analysis of Pathogens.

Metal-organic framework (MOF) thin films with flexible nature and prominent qualities have opened doors to new technological applications in different fields. Herein, we propose an electrochemical biosensor for the dual detection of Staphylococcus aureus based on the electrodeposition of Cu metal-organic framework (Cu-MOF) thin films. The promising sensing layer with features of good electronic conductivity and enhanced electron-transfer property can not only identify S. aureus through specific micrococcal nucleases in the supernatant but also detect the pathogen directly via aptamer recognition. The dual analysis design ensures the accuracy of this method for S. aureus detection in the range of 7-7 × 106 cfu/mL with the limits of detection of 1.9 and 5.2 cfu/mL. Moreover, the analytical method validation confirmed that the biosensor could efficiently work in complex biological samples, showing good selectivity and specificity and great potential for clinical diagnosis. More importantly, the current proposed strategy is simple and easy to implement without the need for extra signaling elements, which is convenient for timely clinical detection.

Ultrasensitive and selective molecularly imprinted electrochemical oxaliplatin sensor based on a novel nitrogen-doped carbon nanotubes/Ag@cu MOF as a signal enhancer and reporter nanohybrid.

Asensitive and selective molecular imprinted polymeric network (MIP) electrochemical sensor is proposed for the determination of anti-cancer drug oxaliplatin (OXAL). The polymeric network [poly(pyrrole)] was electrodeposited on a glassy carbon electrode (GCE) modified with silver nanoparticles (Ag) functionalized Cu-metal organic framework (Cu-BDC) and nitrogen-doped carbon nanotubes (N-CNTs). The MIP-Ag@Cu-BDC /N-CNTs/GCE showed an observable reduction peak at -0.14V, which corresponds to the Cu-BDC reduction. This peak increased and decreased by eluting and rebinding of OXAL, respectively. The binding constant between OXAL and Cu-BDC was calculated to be 3.5 ± 0.1 × 107mol-1L. The electrochemical signal (∆i) increased with increasing OXAL concentration in the range 0.056-200ngmL-1 with a limit of detection (LOD, S/N = 3) of 0.016ngmL-1. The combination of N-CNTs and Ag@Cu-BDC improves both the conductivity and the anchoring sites for binding the polymer film on the surface of the electrode. The MIP-based electrochemical sensor offered outstanding sensitivity, selectivity, reproducibility, and stability. The MIP-Ag@Cu-BDC /N-CNTs/GCE was applied to determine OXAL in pharmaceutical injections, human plasma, and urine samples with good recoveries (97.5-105%) and acceptable relative standard deviations (RSDs = 1.8-3.2%). Factors affecting fabrication of MIP and OXAL determination were optimized using standard orthogonal design using L25 (56) matrix. This MIP based electrochemical sensor opens a new venue for the fabrication of other similar sensors and biosensors.

Green synthesis of Ag–Pt bimetallic nanoparticles supported on the Metal–Organic framework (MOF)–Derived metal oxides (γ-Fe2O3/CuO) nanocomposite as a reusable heterogeneous nanocatalyst and nanophotocatalyst

The heterogeneous environmentally friendly catalyst and photocatalyst based on Ag, Pt, Ag–Pt nanoparticles (NPs) loading on the γ-Fe2O3/CuO nanocomposite which was derived from Fe-metal organic framework (Fe-MIL-88B) and Cu-metal organic framework (Cu (tpa)) was introduced. The catalytic and photocatalytic activities of Ag–Pt loading on the γ-Fe2O3/CuO nanocomposite were performed for a reduction process (4-nitrophenol (4-Nip) to 4-aminophenol (4-Amp)), and decomposition organic dyes (AB92, MB) in the LED light. Metal-organic framework (MOFs) composed with inorganic and organic linker which used as suitable precursors to obtain different type of nanostructures for environmental applications. Here, we have applied γ-Fe2O3/CuO to prepare a series of noble metal and bimetallic nanoparticles (Ag, Pt, AgPt) decorated γ-Fe2O3/CuO (M (Ag, Pt, AgPt) @ γ-Fe2O3/CuO) as efficient catalyst and photocatlyst. Characterization of the as-obtained compounds were verified with various techniques, like FT-IR, XRD, SEM, EDS elemental mappings, EIS, PL and, photocurrent response. According to the practical result, AgPt@γ-Fe2O3/CuO with the highest electron accepting and transporting properties capacity indicated the extraordinary performance as catalyst and photocatalyst. These results verified the fast charrier transfer and high synergistic effect between the γ-Fe2O3/CuO and metal nanoparticles in the nanostructures.