Light/pH dual-responsive magnetic metal-organic frameworks composites for phosphorylated peptide enrichment

Metal-organic frameworks(MOFs)combined with specific ligands are highly adaptable smart materials that can respond to external and physiological stimuli.In this study,we introduced a pyridinyl zwitterionic ligand with light/pH dual response into magnetic MOF composite(Fe_(3)O_(4)@ZW-MOF)for enrichment of phosphorylated peptides for the first time.The introduction of the developed ligand gives MOF material dual response properties.Light stimulation affects the generation/disappearance of free radicals of the pyridine derivative,resulting in a change in the charge gradient of the zwitterion,and zwitterion can also regulate the p H of the solution by adding acid or base.Therefore,the reversible capture and release of phosphorylated peptides can be easily achieved by adjusting light and pH.The established phosphorylated peptide enrichment platform exhibits high sensitivity(detection limit of 1 fmol),high selectivity(β-casein:BSA,1:1000),and good reusability(7 cycles).In addition,the method was applied to the enrichment of phosphorylated peptides in complex systems(non-fat milk and human serum),demonstrating the feasibility of this method for phosphoproteom analysis.In conclusion,the synthesized Fe_(3)O_(4)@ZW-MOF is a promising MOF material,which provides the possibility to advance the application of responsive MOFs materials in proteomics.

Hollow Metal-Organic Framework/MXene/Nanocellulose Composite Films for Giga/Terahertz Electromagnetic Shielding and Photothermal Conversion

With the continuous advancement of communication technology,the escalating demand for electromagnetic shielding interference(EMI)materials with multifunctional and wideband EMI performance has become urgent.Controlling the electrical and magnetic components and designing the EMI material structure have attracted extensive interest,but remain a huge challenge.Herein,we reported the alternating electromagnetic structure composite films composed of hollow metal-organic frameworks/layered MXene/nanocellulose(HMN)by alternating vacuum-assisted filtration process.The HMN composite films exhibit excellent EMI shielding effectiveness performance in the GHz frequency(66.8 dB at Kaband)and THz frequency(114.6 dB at 0.1-4.0 THz).Besides,the HMN composite films also exhibit a high reflection loss of 39.7 dB at 0.7 THz with an effective absorption bandwidth up to 2.1 THz.Moreover,HMN composite films show remarkable photothermal conversion performance,which can reach 104.6℃under 2.0 Sun and 235.4℃under 0.8 W cm^(−2),respectively.The unique micro-and macrostructural design structures will absorb more incident electromagnetic waves via interfacial polarization/multiple scattering and produce more heat energy via the local surface plasmon resonance effect.These features make the HMN composite film a promising candidate for advanced EMI devices for future 6G communication and the protection of electronic equipment in cold environments.

Ultralight Magnetic and Dielectric Aerogels Achieved by Metal-Organic Framework Initiated Gelation of Graphene Oxide for Enhanced Microwave Absorption

The development of a convenient methodology for synthesizing the hierarchically porous aerogels comprising metal–organic frameworks(MOFs)and graphene oxide(GO)building blocks that exhibit an ultralow density and uniformly distributed MOFs on GO sheets is important for various applications.Herein,we report a facile route for synthesizing MOF/reduced GO(rGO)aerogels based on the gelation of GO,which is directly initiated using MOF crystals.Free metal ions exposed on the surface of MIL-88A nanorods act as linkers that bind GO nanosheets to a three-dimensional porous network via metal–oxygen covalent or electrostatic interactions.The MOF/rGOderived magnetic and dielectric aerogels Fe_(3)O_(4)@C/rGO and Ni-doped Fe_(3)O_(4)@C/rGO show notable microwave absorption(MA)performance,simultaneously achieving strong absorption and broad bandwidth at low thickness of 2.5(-58.1 dB and 6.48 GHz)and 2.8 mm(-46.2 dB and 7.92 GHz)with ultralow filling contents of 0.7 and 0.6 wt%,respectively.The microwave attenuation ability of the prepared aerogels is further confirmed via a radar cross-sectional simulation,which is attributed to the synergistic effects of their hierarchically porous structures and heterointerface engineering.This work provides an effective pathway for fabricating hierarchically porous MOF/rGO hybrid aerogels and offers magnetic and dielectric aerogels for ultralight MA.

Synthesis, Crystal Structure, and Magnetic Properties of a Co Metal-organic Framework with Mixed Dicarboxylate and Tricarboxylate Ligands

One new mixed-ligand coordination polymer,namely[Co2（btc）（bpdc）（0.5）（py）3]n（1）,was hydrothermally synthesized using biphenyl-2,4,4＇-tricarboxylic acid（H3btc） as a main building block,along with two auxiliary ligands（H2bpdc = 2,2＇-bipyridine-5,5＇-dicarboxylic acid and py =pyridine）.The product 1 was characterized by IR spectroscopy,elemental,thermogravimetric,and single-crystal X-ray diffraction analyses.Single-crystal X-ray diffraction studies show that compound 1 possesses an intricate 3D metal-organic framework based on tetracobalt（Ⅱ） units.Magnetic susceptibility measurement indicates that compound 1 shows an antiferromagnetic coupling between the Co（Ⅱ） ions.

Syntheses,Structures,Luminescence and Magnetic Properties of Three New Metal-organic Frameworks Based on Rigid Carbazole Ligand

Three new metal-organic frameworks [Cd（L）（obba）]·H）2O（1）,[Co（L）（obba）]·MeCN（2） and [Cd_2（L）_2（ip）_2]·6H_2O·DMF（3）（H_2obba = 4,4？-oxybisbenzoic acid,H2 ip = m-phthalic acid） have been successfully synthesized based on the controllable self-assembly of 9-ethyl-3,6-diimidazolyl-carbazole（L）,varied carboxylates and different metal ions under solvothermal conditions,which were characterized by single-crystal X-ray diffraction,elemental analysis,IR spectroscopy and thermogravimetry. Furthermore,luminescence and magnetic susceptibility of compound 2 are also investigated in detail. Single-crystal X-ray diffraction and topology analysis reveal that complexes 1~3 exhibit similar two-dimensional（2D） networks.

Confined magnetic vortex motion from metal-organic frameworks derived Ni@C microspheres boosts electromagnetic wave energy dissipation

Magnetic domain structure plays an important role in regulating the electromagnetic properties, which dominatesthe magnetic response behaviors. Herein, unique magnetic vortex domain is firstly obtained in the Ni nanoparticles (NPs) reduced from the Ni-based metal-organic frameworks (MOFs) precursor. Due to both the highsymmetry spheres and boundary restriction of graphited carbon shell, confined magnetic vortex structure isgenerated in the nanoscale Ni core during the annealing process. Meanwhile, MOFs-derived Ni@C assemblypowders construct special magnetic flux distribution and electron migration routes. MOFs-derived Ni@C microspheres exhibit outstanding electromagnetic (EM) wave absorption performance. The minimum reflection lossvalue of Ni@C–V microspheres with vortex domain can reach 54.6 dB at only 2.5 mm thickness, and theefficient absorption bandwidth up to 5.0 GHz at only 2.0 mm. Significantly, configuration evolution of magneticvortex driven by the orientation and reversion of polarity core boosts EM wave energy dissipation. Magneticcoupling effect among neighboring Ni@C microspheres significantly enhances the magnetic reaction intensity.Graphitized carbon matrix and heterojunction Ni–C interfaces further offer the conduction loss and interfacialpolarization. As result, MOFs-derived Ni@C–V powders display unique magnetic vortex, electronic migrationnetwork, and high-performance EM wave energy dissipation.

Magnetic Property of a Three-dimensional Copper Metal-organic Framework

A copper metal-organic framework（MOF） compound based on 2,5-thiophenedicarboxylic acid（H2 TDC） ligand, namely Cu（TDC）（H2 O）？DMA（1, DMA = N,N？-dimethylacetamide）, has been synthesized in gram-scale via a one-pot solvothermal route in a high yield of 81.3%. Single-crystal X-ray analysis reveals that the structure of 1 features a three-dimensional（3D） open framework constructed by TDC interconnecting 1D chains of [-Cu（COO）（H2 O）Cu-]n. Thermal property was investigated by TG-MS. The magnetic measurements indicate the existence of weak antiferromagnetic interactions between the Cu2＋ centers in 1.

Synthesis, Structure, and Magnetic Properties of a New 2D Cobalt(Ⅱ) Metal-organic Framework

Rational design of magnetic materials with desired magnetic properties has attracted wide interest in recent decades. Herein, we present a new 2D cobalt（II） metal-organic framework, namely [Co（MQ）2（V2O6）2]n·4nH2O 1, which was hydrothermally synthesized by the reaction of Co（NO3）2·4H2O, N-methyl-4,4′-bipyridinium（MQ＋） chlorine salt and NH4VO3. Single-crystal X-ray diffraction analysis reveals that 1 crystallizes in C2/c space group with a = 16.290（5）, b = 7.815（2）, c = 25.297（7） A, β = 108.459（5）°, V = 3054.8（15） A3, Z = 4, Dc = 1.890 g/cm3, μ = 1.791 mm-1, F（000） = 1748, the final R = 0.0444 and wR = 0.1208 with I 〉 2σ（I）. The individual Co（II） is connected and well separated by diamagnetic [V2O6]2-linkers. Magnetic measurements confirm that 1 exhibits ferrimagnetic interactions.

Magnetic and electronic properties of two-dimensional metal-organic frameworks TM_(3)(C_(2)NH)_(12)

The ferromagnetism of two-dimensional(2D)materials has aroused great interest in recent years,which may play an important role in the next-generation magnetic devices.Herein,a series of 2D transition metal-organic framework materials(TM-NH MOF,TM=Sc-Zn)are designed,and their electronic and magnetic characters are systematically studied by means of first-principles calculations.Their structural stabilities are examined through binding energies and ab-initio molecular dynamics simulations.Their optimized lattice constants are correlated to the central TM atoms.These 2D TM-NH MOF nanosheets exhibit various electronic and magnetic performances owing to the effective charge transfer and interaction between TM atoms and graphene linkers.Interestingly,Ni-and Zn-NH MOFs are nonmagnetic semiconductors(SM)with band gaps of 0.41 eV and 0.61 eV,respectively.Co-and Cu-NH MOFs are bipolar magnetic semiconductors(BMS),while Fe-NH MOF monolayer is a half-semiconductor(HSM).Furthermore,the elastic strain could tune their magnetic behaviors and transformation,which ascribes to the charge redistribution of TM-3d states.This work predicts several new 2D magnetic MOF materials,which are promising for applications in spintronics and nanoelectronics.

Accelerating Oxygen Electrocatalysis Kinetics on Metal-Organic Frameworks via Bond Length Optimization

Metal-organic frameworks(MOFs)have been developed as an ideal platform for exploration of the relationship between intrinsic structure and catalytic activity,but the limited catalytic activity and stability has hampered their practical use in water splitting.Herein,we develop a bond length adjustment strategy for optimizing naphthalene-based MOFs that synthesized by acid etching Co-naphthalenedicarboxylic acid-based MOFs(donated as AE-CoNDA)to serve as efficient catalyst for water splitting.AE-CoNDA exhibits a low overpotential of 260 mV to reach 10 mA cm^(−2)and a small Tafel slope of 62 mV dec^(−1)with excellent stability over 100 h.After integrated AE-CoNDA onto BiVO_(4),photocurrent density of 4.3 mA cm^(−2)is achieved at 1.23 V.Experimental investigations demonstrate that the stretched Co-O bond length was found to optimize the orbitals hybridization of Co 3d and O 2p,which accounts for the fast kinetics and high activity.Theoretical calculations reveal that the stretched Co-O bond length strengthens the adsorption of oxygen-contained intermediates at the Co active sites for highly efficient water splitting.

Synergistic catalysis of the N-hydroxyphthalimide on flower-like bimetallic metal-organic frameworks for boosting oxidative desulfurization

Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel oils.In this work,Ni-doped Co-based bimetallic metal-organic framework(CoNi-MOF)is fabricated to disperse N-hydroxyphthalimide(NHPI),in which the whole catalyst provides plentiful synergic catalytic effect to improve the performance of oxidative desulfurization(ODS).As a bimetallic MOF,the second metal Ni doping results in the flower-like morphology and the modification of electronic properties,which ensure the exposure of NHPI and strengthen the synergistic effect of the overall catalyst.Compared with the monometallic Co-MOF and naked NHPI,the NHPI@CoNi-MOF triggers the efficient activation of molecular oxygen and improves the ODS performance without an initiator.The sulfur removal of dibenzothiophene-based model oil reaches 96.4%over the NHPI@CoNi-MOF catalyst in 8 h of reaction.Furthermore,the catalytic product of this aerobic ODS reaction is sulfone,which is adsorbed on the catalyst surface due to the difference in polarity.This work provides new insight and strategy for the design of a strong synergic catalytic effect between NHPI and bimetallic supports toward high-activity aerobic ODS materials.

Metal-organic frameworks and their composites for advanced lithium-ion batteries:Synthesis,progress and prospects

Metal-organic frameworks(MOFs)are among the most promising materials for lithium-ion batteries(LIBs)owing to their high surface area,periodic porosity,adjustable pore size,and controllable chemical composition.For instance,their unique porous structures promote electrolyte penetration,ions transport,and make them ideal for battery separators.Regulating the chemical composition of MOF can introduce more active sites for electrochemical reactions.Therefore,MOFs and their related composites have been extensively and thoroughly explored for LIBs.However,the reported reviews solely include the applications of MOFs in the electrode materials of LIBs and rarely involve other aspects.A systematic review of the application of MOFs in LIBs is essential for understanding the mechanism of MOFs and better designing related MOFs battery materials.This review systematically evaluates the latest developments in pristine MOFs and MOF composites for LIB applications,including MOFs as the main materials(anode,cathode,separators,and electrolytes)to auxiliary materials(coating layers and additives for electrodes).Furthermore,the synthesis,modification methods,challenges,and prospects for the application of MOFs in LIBs are discussed.

Metal-organic frameworks in oral drug delivery

Metal-organic frameworks(MOFs)offer innovative solutions to the limitations of traditional oral drug delivery systems through their unique combination of metal ions and organic ligands.This review systematically examines the structural properties and principles of MOFs,setting the stage for their application in drug delivery.It discusses various classes of MOFs,including those based on zirconium,iron,zinc,copper,titanium,aluminum,potassium,and magnesium,assessing their drug-loading capacities,biocompatibility,and controlled release mechanisms.The effectiveness of MOFs is illustrated through case studies that highlight their capabilities in enhancing drug solubility,providing protection against the harsh gastrointestinal environment,and enabling precise drug release.The review addresses potential challenges,particularly the toxicity concerns associated with MOFs,and calls for further research into their biocompatibility and interactions with biological systems.It concludes by emphasizing the potential of MOFs in revolutionizing oral drug delivery,highlighting the critical need for comprehensive research to harness their full potential in clinical applications.

Temperature-feedback two-photon-responsive metal-organic frameworks for efficient photothermal therapy

The realization of real-time thermal feedback for monitoring photothermal therapy(PTT)under near-infrared(NIR)light irradiation is of great interest and challenge for antitumor therapy.Herein,by assembling highly efficient photothermal conversion gold nanorods and a temperature-responsive probe((E)-4-(4-(diethylamino)styryl)-1-methylpyridin-1-ium,PyS)within MOF-199,an intelligent nanoplatform(AMPP)was fabricated for simultaneous chemodynamic therapy and NIR light-induced temperature-feedback PTT.The fluorescence intensity and temperature of the PyS probe are linearly related due to the restriction of the rotation of the characteristic monomethine bridge.Moreover,the copper ions resulting from the degradation of MOF-199 in an acidic microenvironment can convert H_(2)O_(2)into•OH,resulting in tumor ablation through a Fenton-like reaction,and this process can be accelerated by increasing the temperature.This study establishes a feasible platform for fabricating highly sensitive temperature sensors for efficient temperature-feedback PTT.

Photophysics of metal-organic frameworks:A brief overview

Metal-organic frameworks(MOFs),which are self-assembled porous coordination materials,have garnered considerable attention in the fields of optoelectronics,photovoltaic,photochemistry,and photocatalysis due to their diverse structures and excellent tunability.However,the performance of MOF-based optoelectronic applications currently falls short of the industry benchmark.To enhance the performance of MOF materials,it is imperative to undertake comprehensive investigations aimed at gaining a deeper understanding of photophysics and sequentially optimizing properties related to photocarrier transport,recombination,interaction,and transfer.By utilizing femtosecond laser pulses to excite MOFs,time-resolved optical spectroscopy offers a means to observe and characterize these ultrafast microscopic processes.This approach adds the time coordinate as a novel dimension for comprehending the interaction between light and MOFs.Accordingly,this review provides a comprehensive overview of the recent advancements in the photophysics of MOFs and additionally outlines potential avenues for exploring the time domain in the investigation of MOFs.

Insights into microscopic fabrication, macroscopic forms and biomedical applications of alginate composite gel containing metal-organic frameworks

Overcoming the poor physicochemical properties of pure alginate gel and the inherent shortcomings of pure metal-organic framework(MOF),alginate/MOF composite gel has captured the interest of many researchers as a tunable platform with high stability,controllable pore structure,and enhanced biological activity.Interestingly,different fromthe traditional organic or inorganic nanofillers physically trapped or chemically linked within neTtworks,MOFs crystals can not only be dispersed by crosslinking polymerization,but also support self-assembly in-situ under the help of chelating cations with alginate.The latter is influenced by multiple factors and may involve some complex mechanisms of action,which is also a topic discussed deeply in this article while summarizing different preparation routes.Furthermore,various physical and chemical levels of improvement strategies and availablemacroforms are summarized oriented towards obtaining composite gel with ideal performance.Finally,the application status of this composite system in drug delivery,wound healing and other biomedical fields is further discussed.And the current limitations and future development directions are shed light simultaneously,which may provide guidance for the vigorous development of these composite systems.

Highly Sensitive Detection of Strontium Ions Using Metal-Organic Frameworks Functionalized Solid-state Nanochannels

Strontium-90,a highly radioactive isotope,accumulates within the food chain and skeletal structure,posing significant risks to human health.There is a critical need for a sensitive detection strategy for Strontium-90 in complex environmental samples.Here,solid-state nanochannels,modified with metal-organic frameworks(MOF)and specific aptamers,were engineered for highly sensitive detection of strontium ion(Sr^(2+)).The synergistic effect between the reduced effective diameter of the nanochannels due to MOF and the specific binding of Sr^(2+) by aptamers amplifies the difference in ionic current signals,enhancing detection sensitivity significantly.The MOF-modified nanochannels exhibit highly sensitive detection of Sr^(2+),with a limit of detection(LOD)being 0.03 nmol·L^(-1),whereas the LOD for anodized aluminum oxide(AAO)without the modified MOF nanosheets is only 1000 nmol·L^(-1).These findings indicate that the LOD of Sr^(2+) detected by the MOF-modified nanochannels is approximately 33,000 times higher than that by the nanochannels without MOF modification.Additionally,the highly reliable detection of Sr^(2+) in various water samples was achieved,with a recovery rate ranging from 94.00%to 118.70%.This study provides valuable insights into the rapidly advancing field of advanced nanochannel-based sensors and their diverse applications for analyzing complex samples,including environmental contaminant detection,food analysis,medical diagnostics,and more.

Expediting^(*)OH accumulation kinetics on metal-organic frameworks-derived CoOOH with CeO_(2) “accelerator” for electrocatalytic 5-hydroxymethylfurfural oxidation valorization

In this work,nickel foam supported CeO_(2)-modified CoBDC(BDC stands for terephthalic acid linker)metal-organic frameworks(NF/CoBDC@CeO_(2)) are prepared by hydrothermal and subsequent impregnation methods,which can be further transformed to NF/CoOOH@CeO_(2) by reconstruction during the electrocatalytic test.The obtained NF/CoOOH@CeO_(2) exhibits excellent performance in electrocatalytic oxidation of 5-hydroxymethylfurfural(HMF) because the introduction of CeO_(2) can optimize the electronic structure of the heterointerface and accelerate the accumulation of ^(*)OH.It requires only a potential of 1.290 V_(RHE) to provide a current density of 50 mA cm^(-2) in 1.0 M KOH+50 mM HMF,which is 222 mV lower than that required in 1,0 M KOH(1.512 V_(RHE)).In addition,density-functional theory calculation results demonstrate that CeO_(2) biases the electrons to the CoOOH side at the heterointerface and promotes the adsorption of ^(*)OH and ^(*)HMF on the catalyst surface,which lower the reaction energy barrier and facilitate the electrocata lytic oxidation process.

Metal-organic-framework-derived copper-based catalyst for multicomponent C-S coupling reaction

Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling reactions.In this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of CTAB.Concurrently,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.

Regulating interfacial behavior of zinc metal anode via metal-organic framework functionalized separator

Aqueous zinc ion batteries(AZIBs)are one of the promising energy storage devices.However,uncontrolled dendrite and side reactions have seriously hindered its further application.In this study,the metal-organic framework(MOF)functionalized glass fiber separator(GF-PFC-31)was used to regulate interfacial behavior of zinc metal anode,enabling the development of high-performance AZIBs.In PFC-31,there areπ-πinteractions between two adjacent benzene rings with a spacing of 3.199 A.This spacing can block the passage of[Zn(H_(2)O)_6]^(2+)(8.6 A in diameter)through the GF-PFC-31 separator to a certain extent,which promotes the deposition process of Zn ions.In addition,the sulfonic acid group(-S03H)contained in GF-PFC-31 can form a hydrogen bonding network with H_(2)O,which can provide a desolvation effect and reduce the side reaction.Consequently,GF-PFC-31 separator achieves uniform deposition of Zn ions.The Zn‖GF-PFC-31‖Zn symmetric cell exhibits stable cycle life(3000 h at 1.2 mA cm^(-2),2000 h at 0.3 mA cm^(-2),and 2000 h at 5.0 mA cm^(-2)),and Zn‖GF-PFC-31‖MnO_(2) full cell with GF-PFC-31 separator can cycle for 1000 cycles at 1.2 A g^(-1)with capacity retention rate of 82.5%.This work provides a promising method to achieve high-performance AZIBs.