RESUMEN

In this study, covalent organic frameworks (COFs) were grown in situ on magnetic nitrogen-doped graphene foam (MNGF), and the resulting composite of COFs-modified MNGF (MNC) was wrapped by molecularly imprinted polymers (MNC@MIPs) for specifically capturing SAs. A magnetic solid phase extraction (MSPE) method for SAs was established using MNC@MIPs with good magnetic responsiveness. The adsorption performance of MNC@MIPs was superior to that of non-molecularly imprinted polymers (MNC@NIPs), with shorter adsorption/desorption time and higher imprinting factors. A high-efficiency SAs analytical method was developed by fusing HPLC and MNC@MIPs-based MSPE. This approach provides excellent precision, a low detection limit, and wide linearity. By analyzing fish samples, the feasibility of the approach was confirmed, with SAs recoveries and relative standard deviations in spiked samples in the ranges of 77.2-112.7 % and 2.0-7.2 %, respectively. This study demonstrated the potential use of MNC@MIPs-based MSPE for efficient extraction and quantitation of trace hazards in food.

Asunto(s)

RESUMEN

In this research, the TT-COF(Fe)@NH2-CNTs was innovatively prepared through a post-modification synthetic process functionalized TT-COF@NH2-CNTs with active site (Fe), where TT-COF@NH2-CNTs was prepared via a one-pot strategy using 5,10,15,20-tetrakis (para-aminophenyl) porphyrin (TTAP), 2,3,6,7-tetra (4-formylphenyl) tetrathiafulvalene (TTF) and aminated carbon nanotubes (NH2-CNTs) as raw materials. The complex TT-COF(Fe)@NH2-CNTs material possessed porous structures, outstanding conductivity and rich catalytic sites. Thus, it can be adopted to construct electrochemical sensor with glassy carbon electrode (GCE). The TT-COF(Fe)@NH2-CNTs/GCE can selectively detect luteolin (Lu) with a wide linear plot ranging from 0.005 to 3 µM and a low limit of detection (LOD) of 1.45 nM (S/N = 3). The Lu residues in carrot samples were determined using TT-COF(Fe)@NH2-CNTs sensor and UV-visible (UV-Vis) approach. This TT-COF(Fe)@NH2-CNTs/GCE sensor paves the way for the quantification of Lu through a cost-efficient and sensitive electrochemical approach, which can make a significant step in the sensing field based on crystalline COFs.

Asunto(s)

RESUMEN

Electrocatalytic reduction of nitrate to ammonia has been considered a promising and sustainable pathway for pollutant treatment and ammonia has significant potential as a clean energy. Therefore, the method has received much attention. In this work, Cu/Fe 2D bimetallic metal-organic frameworks were synthesized by a facile method applied as cathode materials without high-temperature carbonization. Bimetallic centers (Cu, Fe) with enhanced intrinsic activity demonstrated higher removal efficiency. Meanwhile, the 2D nanosheet reduced the mass transfer barrier between the catalyst and nitrate and increased the reaction kinetics. Therefore, the catalysts with a 2D structure showed much better removal efficiency than other structures (3D MOFs and Bulk MOFs). Under optimal conditions, Cu/Fe-2D MOF exhibited high nitrate removal efficiency (87.8%) and ammonium selectivity (89.3%) simultaneously. The ammonium yielded up to significantly 907.2 µg/(hr·mgcat) (7793.8 µg/(hr·mgmetal)) with Faradaic efficiency of 62.8% at an initial 100 mg N/L. The catalyst was proved to have good stability and was recycled 15 times with excellent effect. DFT simulations confirm the reduced Gibbs free energy of Cu/Fe-2D MOF. This study demonstrates the promising application of Cu/Fe-2D MOF in nitrate reduction to ammonia and provides new insights for the design of efficient electrode materials.

Asunto(s)

RESUMEN

Two isostructural, three-dimensional, interpenetrated amino-functionalized Metal-Organic Frameworks (Co-2AIN-MOF and Cd-2AIN-MOF) based on 2-aminoisonicotinic acid (2AIN) were synthesized, structurally characterized and determined. Based on the PXRD analysis, the solvent exchange hardly changed their framework structure, and the samples fully activated by methanol can be achieved and examined by infrared spectroscopy. Due to the presence of the carbonyl group and free amino groups in the pore of the framework, the NH3 uptakes of Co-2AIN-MOF and Cd-2AIN-MOF are 11.70 and 13.81 mmol/g and at 1 bar, respectively. In-situ Infrared spectroscopy and DFT calculations revealed the different adsorption sites and processes between Co-2AIN-MOF and Cd-2AIN-MOF.

RESUMEN

Due to their exceptional optical properties and adjustable functional characteristics, hydrogen-bonded organic frameworks (HOFs) demonstrate significant potential in applications such as sensing, information encryption. However, studies on the synthesis of HOFs designed to construct multifunctional platforms are scant. In this work, we report the synthesis of a new fluorescent HOF by assembling melem and isophthalic acid (IPA), designated as HOF-IPA. HOF-IPA exhibited good selectivity and sensitivity towards Fe3+, making it suitable as a fluorescent sensor for Fe3+ detection. The sensor achieved satisfactory recoveries ranging from 97.79 % to106.42 % for Fe3+ sensing, with a low relative standard deviation (RSD) of less than 3.33 %, indicating significant application potential for HOF-IPA. Due to the ability of F- to mask the electrostatic action on the surface of Fe3+ and inhibit the photoelectron transfer (PET) of HOF-IPA, the HOF-IPA - Fe3+ system can be utilized as a fluorescent "off-on" sensor for F- detection. Additionally, owing to the colorless, transparent property of HOF-IPA in aqueous solution under sunlight and its blue fluorescence property under UV light (color) or microplate reader (fluorescence intensity), HOF-IPA based ink can be used for various types of information encryption, and all yielding favorable outcomes.

RESUMEN

Copper-catalyzed click chemistry offers creative strategies for activation of therapeutics without disrupting biological processes. Despite tremendous efforts, current copper catalysts face fundamental challenges in achieving high efficiency, atom economy, and tissue-specific selectivity. Herein, we develop a facile "mix-and-match synthetic strategy" to fabricate a biomimetic single-site copper-bipyridine-based cerium metal-organic framework (Cu/Ce-MOF@M) for efficient and tumor cell-specific bioorthogonal catalysis. This elegant methodology achieves isolated single-Cu-site within the MOF architecture, resulting in exceptionally high catalytic performance. Cu/Ce-MOF@M favors a 32.1-fold higher catalytic activity than the widely used MOF-supported copper nanoparticles at single-particle level, as first evidenced by single-molecule fluorescence microscopy. Furthermore, with cancer cell-membrane camouflage, Cu/Ce-MOF@M demonstrates preferential tropism for its parent cells. Simultaneously, the single-site CuII species within Cu/Ce-MOF@M are reduced by upregulated glutathione in cancerous cells to CuI for catalyzing the click reaction, enabling homotypic cancer cell-activated in situ drug synthesis. Additionally, Cu/Ce-MOF@M exhibits oxidase and peroxidase mimicking activities, further enhancing catalytic cancer therapy. This study guides the reasonable design of highly active heterogeneous transition-metal catalysts for targeted bioorthogonal reactions.

Asunto(s)

RESUMEN

Covalent organic frameworks (COFs) have emerged as one of the most studied photocatalysts owing to their adjustable structure and bandgaps. However, there is limited research on regulating the light-harvesting capabilities of acceptor building blocks in donor-acceptor (D-A) isomer COFs with different bond orientations. This investigation is crucial for elucidating the structure-property-performance relationship of COF photocatalysts. Herein, a series of D-A isostructural COFs are synthesized with different imine bond orientations using benzothiadiazole and its derivatives-based organic building units. Extended light absorption is achieved in COFs with acceptor groups that have strong electron-withdrawing capacities, although this resulted a decreased hydrogen generation efficiency. Photocatalytic experiments indicated that dialdehyde benzothiadiazole-based COFs, HIAM-0015, exhibit the highest hydrogen generation rate (17.99 mmol g-1 h-1), which is 15 times higher than its isomer. The excellent photocatalytic performance of HIAM-0015 can be attributed to its fast charge separation and migration. This work provides insights into the rational design and synthesis of D-A COFs to achieve efficient photocatalytic activity.

RESUMEN

This work introduces a novel method of recovering bioactive berry natural products (BNPs) using solid phase extraction with metal-organic frameworks (MOF-SPE). Two pyrene-based MOFs with different structural topologies, Al-PyrMOF and Zr-NU-1000, were evaluated for their ability to capture and desorb BNPs, including ellagic acid, quercetin, gallic acid, and p-coumaric acid. Time-dependent BNP uptake via dispersive SPE revealed that NU-1000 outperformed Al-PyrMOF in capturing all BNPs. Our findings show NU-1000 demonstrated a higher and more consistent BNP capture profile, achieving over 90% capture of all BNPs within 36 hours, with only a 9% variation between the most and least effectively captured BNPs. In contrast, Al-PyrMOF, displayed a staggered uptake profile, with a significant 53% difference in capture efficiency between the most and least effectively captured BNP. However, when a BNP mixture was used at a loading concentration of 50 µg/mL, Al-PyrMOF outperformed NU-1000, capturing over 70% of all BNPs. Al-PyrMOF also exhibited improved BNP recovery, with a minimum of two-fold greater amount recovered for all BNPs. Further testing with a BNP mixture at a concentration of 15 µg/mL demonstrated that Al-PyrMOF efficiently concentrated all BNPs, achieving a maximum extraction factor of 2.71 observed for quercetin.

RESUMEN

Singlet oxygen (1O2) is important in the environmental remediation field, however, its efficient production has been severely hindered by the ultrafast self-quenching of the as-generated radical precursors in the Fenton-like reactions. Herein, we elaborately designed lamellar anthraquinone-based covalent organic frameworks (DAQ-COF) with sequential localization of the active sites (C═O) at molecular levels for visible-light-assisted peroxymonosulfate (PMS) activation. Theoretical and experimental results revealed that the radical precursors (SO5·-) were formed in the nearby layers with the migration distance less than 0.34 nm, via PMS donating electrons to the photogenerated holes. This interlayer synergistic effect eventually led to ultraefficient 1O2 production (14.8 µM s-1), which is 12 times that of the highest reported catalyst. As an outcome, DAQ-COF enabled the complete degradation of bisphenol A in 5 min with PMS under natural sunlight irradiation. This interlayer synergistic concept represents an innovative and effective strategy to increase the utilization efficiency of ultrashort-lived radical precursors, providing inspirations for subtle structural construction of Fenton-like catalysts.

RESUMEN

With the rapid expansion of the health food industry, the scope of safety supervision has also increased. However, traditional instrument detection methods cannot meet the requirements for the rapid on-site detection. Hence, the development of a rapid, precise, and simple method for the analysis of illegal additives in health foods is of great importance. In this work, by using FeCo-MOFs as mimetic peroxidase to mediate Au nanorods (Au NRs) etching, a dual-mode immunosensor based on multi-colorimetric and photothermal signals was fabricated to detect furosemide (FUR). In multi-colorimetric channel, the localized surface plasmon resonance (LSPR) peaks of Au NRs shifted blue, resulting in multi-color changes from red to gray to blue and finally to purple. In photothermal channel, the photothermal effect of Au NRs decreased, resulting in temperature changes. In the range of 1.0 × 10-5-1.0 × 10-2 µg/mL, both LSPR peak blue shift and temperature changes were linearly correlated with the logarithm of FUR concentration, with the detection limits were 4.9 × 10-6 and 8.5 × 10-6 µg/mL, respectively. Furthermore, its concentration can be accurately and intuitively assessed through the observation of vivid colorimetric changes. This advancement offers a highly promising approach for the on-site detection of FUR, facilitating timely and efficient monitoring, thereby significantly enhancing regulatory compliance and ensuring consumer safety.

RESUMEN

BACKGROUND: Capillary electrochromatography (CEC) stationary phases have always been the focus of attention. The selection of excellent stationary phases are the key to realize separate of different compounds. Hydrogen-bonded organic frameworks (HOFs) are porous materials connected by hydrogen bonds between molecules, which have the advantages of renewable, high specific surface area and mild synthesis conditions. At present, HOFs are used in gas adsorption and storage, catalysis and drug delivery. Because of its unique advantages, HOFs have a bright future as CEC stationary phases. RESULTS: Using melamine (MA) and 1,3,6,8-tetra (4-carboxylphenyl)pyrene (H4TBAPy) as reaction monomers, a HOFs named MA/PFC-1 was synthesized by solvent evaporation at room temperature. The inner wall of the capillary column was coated with MA/PFC-1 by chemical bonding. Sulfonamides were used as the target analytes. The effects of pH, phosphate buffer solution concentration, organic additive content and applied voltage on sulfonamides separation were investigated. The MA/PFC-1-coated capillary column had good resolution (>1.5) and reproducibility. The intra-day, inter-day, column-to-column, and inter-batch precision of the retention times were 0.03%-0.09%, 0.04%-0.09%, 0.03%-0.14% and 0.06%-0.09%, respectively. The intra-day, inter-day, column-to-column, and inter-batch precision of the peak areas were 0.11%-0.25%, 0.13%-0.20%, 0.12%-0.15% and 0.08%-0.15%, respectively. The MA/PFC-1-coated capillary column was run 150 consecutive times, and the results showed no noticeable change, which proved that this method had good stability. SIGNIFICANCE: This work applied HOFs to CEC. The results show the that MA/PFC-1-coated capillary column has good separation performance. The MA/PFC-1-coated capillary column has been successfully applied to the determination of sulfamethoxazole in tablets, which has practical application value. To open up the application of HOFs in CEC and provide a new idea for developing new CEC stationary phases.

RESUMEN

The reduced nicotinamide adenine dinucleotide (NADH) is a vital biomolecule involved in many biocatalytic processes, and the high cost makes it significant to regenerate NADH in vitro. The photoelectrochemical approach is a promising and environmentally friendly method for sustainable NADH regeneration. However, the free Rh-based mediator ([Cp*Rh (bpy)H2O]2+) in the electrolyte suffers from low efficiency due to the sluggish charge transfer controlled by the diffusion process. Herein, we report an efficient and facile covalent bonding of the Rh-based mediator with the Si-based photocathode for NADH regeneration. The bipyridine-containing covalent organic framework (BpyCOF) layer ensures the even distribution of mediators throughout the surface of the photoelectrode. The graphene interlayer provides a pathway for charge transport and prevents silicon from corrosion. Furthermore, during the synthesis of BpyCOF, it functions as a substrate to promote the growth of the oriented BpyCOF film. The imitated contact between the components of the photocathode favors the charge transfer to the surface to participate in a chemical reaction, thus improving the catalytic performance and the NADH regeneration efficiency, which is four times higher than the reported photocathode modified by the Rh-based mediator. This study offers a new strategy for the construction of photoelectrochemical solar energy conversion devices.

RESUMEN

Porphyrins, known for generating toxic singlet oxygen (1O2) to combat bacteria, face challenges such as hydrophilicity and limited lifespan and 1O2 yield. Conversely, triterpenoid compounds like ammonium glycyrrhizinate (AG) offer antioxidative and antibacterial properties but lack efficacy and stability. Combining them in Metal-Organic Frameworks (MOFs) yields dual-ligand zirconium (Zr)-basedMOFs (M-TG), capitalizing on porphyrins' membrane-disrupting ability and AG's inhibition of bacterial membrane synthesis for a synergistic antibacterial effect. M-TG resolves activity loss, enhances reactive oxygen species (ROS) yield, and extends stability, achieving a remarkable 99.999% sterilization rate. This innovative approach maximizes ligand properties through synergistic effects, promising significant advancements in antibacterial material design.

RESUMEN

To construct an efficient regulating layer for Zn anodes that can simultaneously address the issues of dendritic growth and side reactions is highly demanded for stable zinc metal batteries (ZMBs). Herein, we fabricate a hydrogen-bonded organic framework (HOF) enriched with zincophilic sites as a multifunctional layer to regulate Zn anodes with controlled spatial ion flux and stable interfacial chemistry (MA-BTA@Zn). The framework with abundant H-bonds helps capture H2O and remove the solvated shells on [Zn(H2O)6]2+, leading to suppressed side reactions. The HOF layer also helps form electrolyte-philic surfaces and expose Zn (002) crystal planes which benefit for rapid conduction and uniform deposition of Zn2+, and weakened sides reactions. Additionally, the electrochemically active zincophilic sites (C=O, -NH2 and triazine groups) favor the targeted guidance and penetration of Zn2+ and provide advantageous sites for uniform Zn deposition. High Young's modulus of the HOF layer further contributes to a high interfacial flexibility and stability against Zn plating-associated stress. The MA-BTA@Zn symmetric cells thereby obtain a substantially extended battery life over 1000 h at 4 mA cm-2. The MA-BTA@Zn||Cu half-cell demonstrates a highly reversible Zn stripping/plating process over 1500 cycles with impressive average Coulombic efficiency (CE) of 99.5% at 10 mA cm-2.

RESUMEN

AIMS: Evaluate existing oncology value frameworks in terms of their methodology, structure, characteristics, and functionality using the example of enfortumab vedotin, an approved therapy for urothelial carcinoma. METHODS: A search of PubMed, grey literature, and official websites of relevant international organizations was performed from January 2022 to March 2023. RESULTS: Six frameworks were identified and analyzed, including the American Society of Clinical Oncology's assessment framework, European Society for Medical Oncology's Magnitude of Clinical Benefit Scale, the National Comprehensive Cancer Network's Evidence Blocks, Memorial Sloan Kettering Cancer Center's DrugAbacus, Institute for Clinical and Economic Review's assessment framework, and the Drug Assessment Framework. Comparisons across frameworks were challenging, owing to differing approaches, objectives, perspectives, methodology, and criteria. Based on the results of the EV-301 study (NCT03474107), the European Society for Medical Oncology's Magnitude of Clinical Benefit Scale assigned a score of 4 out of 5 to enfortumab vedotin administered after chemotherapy and immunotherapy. The National Comprehensive Cancer Network's Evidence Blocks enabled assessment of enfortumab vedotin compared with other treatments for locally advanced or metastatic urothelial carcinoma, resulting in the positioning of enfortumab vedotin as a preferred regimen after chemotherapy and immunotherapy. CONCLUSIONS: Application of value frameworks in oncology can contribute to informed value-based decision-making. However, comparisons across frameworks should be made with caution and limited to the same lines of treatment. Enfortumab vedotin may contribute to optimizing outcomes in patients previously treated with chemotherapy and immunotherapy for locally advanced or metastatic urothelial carcinoma.

RESUMEN

Rare-earth elements (REEs) play a crucial role in state-of-the-art technologies and sustainable energy generation. However, conventional production methods of REE often instigate detrimental impacts on environment. Hence, the development of efficient and sustainable hydrometallurgical methods for REE recovery from complex solution has become a crucial research focus. This study investigates a mixed-matrix membrane composed of a highly europium selective metal-organic framework-based adsorbent, Cr-MIL-PMIDA, embedded in sulfonated poly(ether ketone) (SPEK) polymer membrane matrix to preferentially concentrate europium (Eu3+) ions in the presence of other competing cations. The activated membrane notably reduced ionic conductivity for Eu3+ compared to other multivalent ions. Membrane extraction experiments further confirmed the selective behavior, demonstrating slower diffusion for Eu3+ compared to Mg2+ and Zn2+ cations. Especially, at pH 5, Mg2⁺ and Zn2⁺ recovery was greater than 30%, whereas Eu³âº recovery remained lower than 4%. We propose that the strong chemical affinity between the phosphate group and Eu3+ help partition of the Eu3+ ions in the membrane phase and inhibit the diffusion and further partitioning of the Eu3+ ion from bulk solution. Furthermore, we demonstrate the stability of the composite membrane and the embedded MOF particles in aqueous solution for up to 12 days without degradation, attributing it to the robust chemical stability of the MOF structure.

RESUMEN

This article contends that the responsible artificial intelligence (AI) approach-which is the dominant ethics approach ruling most regulatory and ethical guidance-falls short because it overlooks the impact of AI on human relationships. Focusing only on responsible AI principles reinforces a narrow concept of accountability and responsibility of companies developing AI. This article proposes that applying the ethics of care approach to AI regulation can offer a more comprehensive regulatory and ethical framework that addresses AI's impact on human relationships. This dual approach is essential for the effective regulation of AI in the domain of mental health care. The article delves into the emergence of the new "therapeutic" area facilitated by AI-based bots, which operate without a therapist. The article highlights the difficulties involved, mainly the absence of a defined duty of care toward users, and shows how implementing ethics of care can establish clear responsibilities for developers. It also sheds light on the potential for emotional manipulation and the risks involved. In conclusion, the article proposes a series of considerations grounded in the ethics of care for the developmental process of AI-powered therapeutic tools.

Asunto(s)

RESUMEN

Organic linker-based luminescent metal-organic frameworks (LMOFs) have received extensive attention due to their promising applications in chemical sensing, energy transfer, solid-state-lighting and heterogeneous catalysis. Benefiting from the virtually unlimited emissive organic linkers and the intrinsic advantages of MOFs, significant progress has been made in constructing LMOFs with specific emission behaviors and outstanding performances. Among these reported organic linkers, 2,1,3-benzothiadiazole and its derivatives, as unique building units with tunable electron-withdrawing abilities, can be used to synthesize numerous emissive linkers with a donor-bridge-acceptor-bridge-donor type structure. These linkers were utilized to coordinate with different metal nodes, forming LMOFs with diverse underlying nets and optical properties. In this Minireview, 2,1,3-benzothiadiazole and its derivative-based organic linkers and their corresponding LMOFs are summarized with which an emission library is built between the linker structures and the emission behaviors of constructed LMOFs. In particular, the preparation of LMOFs with customized emission properties ranging from deep-blue to near-infrared and sizes from dozens to hundreds of nanometers is discussed in detail. The applications of these LMOFs, including chemical sensing, energy harvesting and transfer, and catalysis, are then highlighted. Key perspectives and challenges for the future development of LMOFs are also addressed.

RESUMEN

Conductive metal-organic frameworks (cMOFs) offer high porosity and electrical conductivity simultaneously, making them ideal for application in chemiresistive sensors. Recently, incorporating foreign elements such as catalytic nanoparticles into cMOFs has become a typical strategy to enhance their sensing properties. However, this approach has led to critical challenges, such as pore blockage that impedes gas diffusion, as well as limited improvement in reversibility. Herein, single-atom catalyst (SAC)-functionalized cMOF is presented as a robust solution to the current limitations. Facile functionalization of SACs in a cMOF can be achieved through electrochemical deposition of metal precursors. As a proof of concept, a Pd SAC-functionalized cMOF is synthesized. The Pd SACs are stabilized at the interplanar sites of cMOF with Pd-N4 coordination while preserving the porosity of the MOF matrix. Notably, the microenvironment created by Pd SACs prevents irreversible structural distortion of cMOFs and facilitates a reversible charge transfer with NO2. Consequently, the cMOF exhibits a fully recoverable NO2 response, which was not previously attainable with the nanoparticle functionalization. Additionally, with the combination of preserved porosity for gas diffusion, it demonstrates the fastest level of response and recovery speed compared to other 2D-cMOFs of this class.

RESUMEN

The overuse of antibiotics poses a serious threat to human health and ecosystems. Therefore, the development of high-performance antibiotic removal materials has attracted increasing attention. However, the adsorption and removal of trace amounts of antibiotics in aqueous systems still face significant challenges. Taking tetracycline (TC) as a representative antibiotic and based on its structural characteristics, a series of TC adsorbents are prepared by grafting alkyl groups to the framework of MIL-101(Cr). The adsorptive capacity of the modified materials for tetracycline markedly surpasses that of MIL-101(Cr), with MIL-101-dod achieving the best adsorption performance. MIL-101-dod demonstrated an outstanding ability to adsorb tetracycline at low concentrations, where a 5.0 mg sample of MIL-101-dod can reduce the concentration of a 90 mL 5 ppm tetracycline solution to below 1 ppb, significantly superior to other sorbents. XPS and IR tests indicate that MIL-101-dod has multiple weak interactions with tetracycline molecules, including C─H…O and C─H…π. This work provides theoretical and experimental support for the development of adsorbents for low-concentration antibiotics.