Search Results (132)

Hierarchical functionalisation of the UiO-66(Zr)-NH₂ metal–organic framework with cysteine, poly(ethylene glycol) (PEG), and the SARS-CoV-2 spike receptor-binding domain (RBD) was developed to enable receptor-specific interaction with the angiotensin-converting enzyme 2 receptor (ACE2) in model cells. Post-synthetic modification using cysteine and heterobifunctional PEG linkers allowed controlled bioconjugation of SpyTag-labelled RBD via SpyTag/SpyCatcher chemistry, while preserving the crystallinity, microporosity, and intrinsic optical properties of the UiO-66(Zr)-NH₂ framework. Comprehensive physicochemical characterisation confirmed successful surface functionalisation, tunable aggregation behaviour, and retention of multimodal optical characteristics. Cellular studies in HEK293T and HeLa cells overexpressing EGFP-tagged ACE2 demonstrated enhanced and selective association and uptake of RBD-functionalised nanoparticles compared with non-targeted analogues. Multimodal fluorescence imaging, fluorescence lifetime imaging microscopy, flow-cytometry, and electron microscopy indicated ACE2-dependent endocytic internalisation, with predominant localisation in endosomal and autophagosomal compartments, while both amine- and cysteine-modified formulations exhibited good biocompatibility. Overall, this study establishes a virus-mimetic, ACE2-targeted UiO-66(Zr)-based nanosystem as a proof-of-concept biointerface platform for receptor-specific cellular delivery and imaging, providing a foundation for future MOF-based nanocarriers exploiting ligand–receptor interactions. Full article

The widespread residual ciprofloxacin (CIP) poses severe environmental and health risks, demanding efficient detection methods. Herein, a Zr–Tb bimetallic MOF (ZTM) was green-synthesized via a room-temperature aqueous route with disodium terephthalate as ligand, and developed as a ratiometric fluorescent probe for CIP detection. Structural characterization confirmed Tb³⁺ was successfully incorporated into the Zr-MOF framework, endowing ZTM with high stability and excellent luminescence. The absorption edge of ZTM (320–330 nm) overlapped with CIP’s 330 nm absorption peak, so 327 nm was selected as the excitation wavelength. Under this excitation, ZTM showed a strong Tb³⁺ emission at 657 nm; upon CIP addition, the 657 nm peak was quenched, while the 491 nm emission was enhanced, realizing a distinct ratiometric response. The ratio I₄₉₁/I₆₅₇ was linear with CIP concentration (0.5–25 μM, R² = 0.992), with a limit of detection far below the statutory 30 μM limit (0.16 μM). ZTM also exhibited excellent selectivity, good pH tolerance (5.0–8.0) and rapid response (1 min). Mechanism analysis revealed that the response was mainly due to the inner filter effect (IFE) between ZTM and CIP. This work provides a green-synthesized MOF probe for sensitive and selective CIP detection in environmental samples. Full article

Arsenic contamination, mainly in the arsenate (As(V)) form, continues to pose a serious threat to groundwater quality worldwide due to its long-term stability and toxicity at very low levels. Herein, we demonstrate, for the first time, a three-dimensional graphene oxide-based nanocomposite composed of Cu nanoparticle-doped, amino-functionalized UiO-66 (Cu/UiO-66-NH₂) anchored on a graphene oxide framework (Cu/UiO-66-NH₂@GO) as a novel and efficient nanosorbent for the rapid removal of As(V) in groundwater-like solutions. The nanocomposite was characterized by SEM and HRTEM to confirm the hybrid structure and by XRD, N₂ adsorption–desorption isotherms, and XPS to investigate crystallinity, porosity, and surface chemistry. The derived material exhibited a highly dispersed morphology and performed rapid arsenate solid-phase extraction to attain equilibration within 10 min and was effective for a wide pH range of 2–11. The best fit for the kinetic profiles was provided by the pseudo-second-order model. Interestingly, the maximum adsorption capacity of 747.9 mg g⁻¹ at pH 6.8 was achieved, demonstrating the benefits of the complementary pairing of dispersive GO sheets and Zr-MOF adsorption domains with Cu-derived active sites. Mechanistically, the enhanced uptake is ascribed to a combination of effects, including electrostatic pre-concentration, ligand exchange, and inner-sphere complexation at metal-oxo nodes; spectroscopic analysis (XPS and FTIR) suggests that the majority of arsenate is immobilized via a strong Zr-O-As bond at coordinatively unsaturated Zr centers, which is in line with t-ZrO₂-like surface domains formed within the nanocomposite. The embedded GO support inhibits further framework interpenetration and enhances active site availability and mass transport, leading to fast and high-capacity arsenate capture in groundwater samples with related conditions. Taken together, this work presents a powerful design concept that integrates unique GO-supported, Cu-modified UiO-66-NH₂ with Zr-O binding motifs to afford high-rate remediation nanocomposites, providing an excellent platform for next-generation arsenate remediation materials. Full article

CO₂ cycloaddition with epoxides offers a sustainable route for CO₂ utilization, yet the simultaneous activation of both substrates remains challenging. Herein, using UiO-66(Zr)-NH₂ (denoted as UZN) as a model system, we illustrate that dual-active sites consisting of unsaturated Zr⁴⁺ centers and amine groups can efficiently accelerate CO₂ fixation with epoxides under visible light. The unique ensemble in UZN optimizes light harvesting, promotes charge carrier separation, and enriches bifunctional active sites for efficient adsorption and activation of epoxides and CO₂. Consequently, UZN exhibits significantly improved CO₂-epoxide cycloaddition performance compared to UiO-66(Zr)-H (denoted as UZH), achieving a PC yield of 99.5%, with a production rate of 9.97 mmol·g⁻¹·h⁻¹. This work establishes a clear coordination–photocatalytic synergy in MOF-based systems and provides fundamental insights and a generalizable strategy for designing advanced catalysts for CO₂ transformation. Full article

In on-site rapid detection, the electrochemical method boasts high sensitivity and rapid response capabilities, while the colorimetric method can provide intuitive visual readings suitable for on-site screening. Therefore, this study developed an innovative dual-mode electrochemical/colorimetric aptasensor for the accurate detection of malathion (MAL) in vegetables. The sensor combines magnetic Fe₃O₄@ZIF-8-DNA composites and CuZr-MOF-cDNA probes, enabling simultaneous detection of the target through electrochemical reactions and colorimetric changes. The introduction of CuZr-MOF not only enhances the sensor’s conductivity but also significantly amplifies the electrochemical signal through its catalytic properties. The magnetic Fe₃O₄@ZIF-8-DNA composite facilitates solid–liquid separation under an external magnetic field. When the target MAL is present, the aptamer binds to the target, causing the CuZr-MOF-cDNA probes to release from the composite, altering the number of free probes in the supernatant and generating varying intensities of colorimetric signals. Meanwhile, the MAL captured in the precipitate by the aptamer is quantitatively detected through electrochemical methods. Experimental results demonstrate that as the target concentration increases, the colorimetric signal intensifies while the electrochemical signal weakens, showing a good linear relationship between the two. The aptasensor’s limit of detection (LOD) for colorimetric and electrochemical modes was 1.57 × 10⁻¹¹ M and 4.76 × 10⁻¹¹ M, respectively, with recoveries ranging from 87.71% to 107.68% and relative standard deviations between 3.23% and 10.75%. This method exhibits high sensitivity, excellent selectivity, and strong reliability, providing a novel technique for the accurate quantification of MAL in vegetables, particularly suited for on-site rapid detection. Full article

The widespread use of antibiotics has taken a heavy toll on the environment, which cannot be ignored. Tetracycline antibiotics (TCs), as representative pharmaceutical contaminants, have emerged as a growing environmental concern due to their persistence and potential ecological risks. This study utilized 1,3,5-benzenetricarboxylic acid (BTC) as a functionalizing reagent to synthesize magnetic nanoparticles NiFe₂O₄-COOH. These were then combined with Zr-MOF to create the magnetic adsorbent designated as NCF@Zr-MOF (where NCF represents carboxyl-functionalized nickel ferrite). Magnetic solid-phase extraction (MSPE) technology was employed to remove two representative tetracycline antibiotics, tetracycline (TC) and chlortetracycline (CTC) from the environment. The Langmuir model fitting revealed maximum adsorption reached 190.85 and 196.32 mg/g for TC and CTC, respectively, both of which conformed to the pseudo-second-order model during the adsorption process with spontaneous, heat-absorbing and entropy-increasing properties. Furthermore, following five cycles of adsorption and desorption, the removal rate for TCs was found to have decreased by 30%, yet the removal of CTCs remained at 95.32%. This adsorbent enables rapid separation via an external magnetic field. With its excellent stability and reusability, NCF@Zr-MOF shows great potential for removing antibiotics from water. Full article

UiO-67(Zr), as a member of Zr-based metal–organic frameworks (MOFs), has attracted much attention owing to its merits, involving large surface area, high pore volume, and good structural stability. However, it is generally inactive in many catalytic reactions due to a lack of active sites. In this work, we report a new strategy, combining vapor-assisted synthesis with acid treatment to create abundant active sites in UiO-67(Zr), resulting from defects. The effects of some synthetic parameters were systematically investigated. As a result, an optimized material named UiO-67(Zr)-V-0.5FA-H, obtained by acid-treating UiO-67(Zr) and prepared with the addition of 0.5 mL formic acid via a vapor-assisted method, exhibited outstanding catalytic performance in the oxidation of dibenzothiophene (DBT), which can completely oxidize DBT in 9 min at 30 °C using H₂O₂ as the oxidant. The calculated turnover frequency reached 150.4 h⁻¹, surpassing those of most reported Zr-MOFs catalysts. In addition, it is demonstrated that UiO-67(Zr)-V-0.5FA-H is a heterogeneous catalyst and can be reused without obvious activity loss. Full article

This study systematically investigates how organic ligand modifications—chain length adjusting and functional group incorporation—regulate the catalytic performance of UiO-66 derivatives for CO₂-to-dimethyl carbonate (DMC) conversion. Through multi-technique characterization (Py-IR, TGA, FT-IR, XPS, etc.) and catalytic tests, Lewis acid/basic sites (LAS/LBS), bulk defects and electron density effects were identified as the three key factors to govern the catalytic activity. The bulk defects were believed to enhance mass transfer. Notably, MOF-801 (shortest ligand) and UiO-66-Br (electron-withdrawing-Br) achieved the highest TOFs of 0.86 h⁻¹ and 1.10 h⁻¹, respectively. While LAS/LBS and electron-rich Zr clusters promote methanol activation, defect-enhanced mass transfer dominated over electronic effects in boosting DMC yield. These insights highlight the tunability of MOFs for CO₂ utilization via rational ligand design. Full article

Metal–organic frameworks (MOFs) are promising materials for environmental remediation, particularly in photocatalysis. In this work, a novel ZMIP nanocomposite was fabricated by integrating MIP-202(Zr) bio-MOF with ZnO nanoparticles. For the first time, ZnO nanoparticles were green-synthesized using water lettuce extract and incorporated into MIP-202(Zr) via a mild hydrothermal route. The resulting hybrid was applied as a visible-light photocatalyst for carbamazepine (CBZ) degradation in real pharmaceutical wastewater. Structural analyses (XRD, FTIR, TEM, EDS) verified the successful incorporation of ZnO into the MIP-202(Zr) framework. The composite exhibited a narrowed bandgap of 2.74 ± 0.1 eV compared to 4.05 ± 0.06 eV for pristine MIP-202 and 3.77 ± 0.04 eV for ZnO, highlighting enhanced visible-light utilization in ZMIP. Operational parameters were optimized using response surface methodology, where CBZ removal reached 99.37% with 84.39% TOC mineralization under the optimal conditions (90 min, pH 6, 15 mg/L CBZ, 1.25 g/L catalyst). The catalyst maintained stable performance over five reuse cycles. Radical quenching and UHPLC-MS analyses identified the dominant reactive oxygen species and generated intermediates, elucidating the degradation mechanism and pathways. Beyond CBZ, the ZMIP photocatalyst effectively degraded other pharmaceuticals, including doxorubicin, tetracycline, paracetamol, and ibuprofen, achieving degradation efficiencies of 82.93%, 76.84%, 72.08%, and 67.71%, respectively. Application on real pharmaceutical wastewater achieved 78.37% TOC removal under the optimum conditions. Furthermore, the supplementation of the photocatalytic system by inorganic oxidants ameliorated the degradation performance, following the order KIO₄ > K₂S₂O₈ > KHSO₅ > H₂O₂. Overall, ZMIP demonstrates excellent activity, reusability, and versatility, underscoring its potential as a sustainable photocatalyst for real wastewater treatment. Full article

Metal–organic frameworks (MOFs) have been increasingly recognized as promising platforms for enzyme modulation, owing to their tunable porosity, high surface area, and versatile chemical functionality. In this review, the potential of MOFs for the inhibition and modulation of protein kinases and phosphatases—key regulators of cellular signaling and disease progression—is examined. The structural fundamentals of MOFs are outlined, followed by a discussion of common synthesis strategies, including solvothermal, microwave-assisted, sonochemical, and mechanochemical methods. Emphasis is placed on how synthesis conditions influence critical features such as particle size, crystallinity, surface chemistry, and functional group accessibility, all of which impact biological performance. Four primary mechanisms of MOF–enzyme interaction are discussed: surface adsorption, active site coordination, catalytic mimicry, and allosteric modulation. Each mechanism is linked to distinct physicochemical parameters, including pore size, surface charge, and metal node identity. Special focus is given to biologically relevant metal centers such as Zr⁴⁺, Ce⁴⁺, Cu²⁺, Fe³⁺, and Ti⁴⁺, which have been shown to contribute to both MOF stability and enzymatic inhibition through Lewis acid or redox-mediated mechanisms. Recent in vitro studies are reviewed, in which MOFs demonstrated selective inhibition of disease-relevant enzymes with minimal cytotoxicity. Despite these advancements, several limitations have been identified, including scalability challenges, limited physiological stability, and potential off-target effects. Strategies such as post-synthetic modification, green synthesis, and biomimetic surface functionalization are being explored to overcome these barriers. Through an integration of materials science, coordination chemistry, and molecular biology, this review aims to provide a comprehensive perspective on the rational design of MOFs for targeted enzyme inhibition in therapeutic contexts. Full article

We investigated the effect of Agrobacterium rhizogenes-mediated transformation mof rolB on adventitious root development and endogenous hormones in ‘duli’ (Pyrus betulaefolia) via transcriptomic analysis of wild-type (WT) and rolB-transformed plants. The formation of root primordia occurred earlier in transgenic ‘duli’ than in the WT plants. At seven days, 57% of the transgenic seedlings had formed root primordia, whereas root primordia first appeared at seven days in WT ‘duli’. The rooting rate of transgenic ‘duli’ and WT plants was 90% and 77.14%, respectively. rolB significantly promoted the formation of secondary roots. Within 20 days, auxin (IAA), gibberellic acid (GA₃), and zeatin riboside (ZR) were higher and abscisic acid (ABA) was lower in transgenic ‘duli’ than in WT plants. Gene Ontology analysis revealed high enrichment in signaling pathways and ADP binding, and Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that several differentially expressed genes were enriched in flavonoid and carotenoid-related pathways and plant hormone signal transduction. rolB induced changes in the expression patterns of several genes involved in hormone biosynthesis, metabolism, and signal transduction pathways in ‘duli’. Weighted gene co-expression network analysis identified the DEGs associated with endogenous hormone levels and indicated that the central genes of modules most strongly correlated with ABA, ZR, IAA, and GA₃ regulate protein synthesis, signaling, and root tissue meristem activity. Protein–protein interaction analysis yielded a co-expression network of physiological and transcriptomic data during rooting and identified key genes at the network core. These findings provide valuable insights into the regulatory mechanisms of rolB and its influence on root development in ‘duli’. Full article

Methylene blue (MB) is a commonly used dye that generates a large amount of dye wastewater during its application. If discharged untreated, it poses a serious threat to water environments and human health. Therefore, the removal of methylene blue from dye wastewater is crucial. In this study, we used zirconium-based metal–organic frameworks (Zr-MOFs) as a precursor and doped them with copper ions to prepare the Cu@Zr-MOFs composite material. Subsequently, we fabricated Cu@Zr-MOFs-PAN nanofiber composites through electrospinning to address the challenge of separating Cu@Zr-MOFs from water. The results indicate that the introduction of copper ions significantly enhances the adsorption capacity of Zr-MOFs for MB, increasing the adsorption amount from 158.0 mg/g to 266.0 mg/g, representing a 68.3% improvement. Furthermore, the prepared Cu@Zr-MOFs-PAN nanofibers exhibited an MB adsorption capacity of 162.1 mg/g, further confirming the successful preparation of Cu@Zr-MOFs-PAN. X-ray photoelectron spectroscopy (XPS) analysis shows that copper doping not only enhances the structural stability of the material but also increases the density of active sites for MB adsorption. This study not only provides an efficient material for the removal of MB from wastewater but also offers an important theoretical basis for the design of novel nanomaterials for environmental pollutant remediation. Full article

Phosphate and fluoride ions are common water pollutants whose presence and excessive discharge cause potential hazards to the environment and human health. MOF materials commonly used to remove phosphate and fluoride ions are usually in powder form, with low recovery during regeneration. Herein, to address these issues, Fe₃O₄@La-Zr-MOFs magnetic composites for phosphate and fluoride removal were fabricated by means of the hydrothermal method. The adsorption properties of the adsorbent were systematically assessed by means of adsorption experiments. The magnetic Fe₃O₄@La-Zr-MOFs exhibited a magnetic recovery efficiency of 93%, and they could maintain outstanding adsorption performance at a broad range of pH values and superior selectivity for phosphate and fluoride ions. The adsorption process conformed to the Langmuir isotherm and pseudo-second-order models, indicating that it was dominated by monomolecular chemisorption. Further characterization of the Fe₃O₄@La-Zr-MOFs before and after adsorption and kinetic thermodynamic investigation revealed that the elimination mechanism of phosphate and fluoride ions by Fe₃O₄@La-Zr-MOFs includes ion exchange, electrostatic interactions, and surface complexation. This study demonstrates that magnetic reusable Fe₃O₄@La-Zr-MOFs composites have great promise for phosphate and fluoride removal and recovery. Full article

As one of the most important platform chemicals, furfural (FAL) can be converted into high-value-added products such as furfuryl alcohol (FOL) through multiple pathways. Zirconium-based MOF-801 demonstrates exceptional catalytic potential for FAL conversion via catalytic transfer hydrogenation (CTH), owing to its unique crystal defects generated during growth. In this study, a series of defective MOF-801 samples were efficiently synthesized using an air–liquid segmented microfluidic technique. The characterization results reveal that the air–liquid segmented flow method not only regulates the defect content of MOF-801 to expose more active sites but also adjusts the crystal size and pore structures by precisely controlling the reaction time. The enhanced defects in MOF-801 significantly improved its catalytic performance. A-MOF-801-64 exhibited the highest activity, achieving over 99% FAL conversion and 98% FOL selectivity under mild conditions (130 °C, 12 h) using isopropanol as the hydrogen donor; this performance surpassed that of other reported Zr-based catalysts. This study will facilitate the practical applications of defect-engineered MOF-801 in upgrading biomass-derived chemicals. Full article

Metal–organic frameworks (MOFs) have great potential for drug delivery systems due to their tunnel pore size, structural versatility, and high surface area. Among them, UiO-67 have recently attracted substantial attention as functional nanocarriers for effective delivery of small molecule chemical drugs. However, the influence of the size on cellular uptake of UiO-67 remains ambiguous. Here, we use polyvinyl pyrrolidone (PVP) as the capping agent of UiO-67 to synthesize spherical Zr-based MOFs with various diameters, including 40 nm, 60 nm, and 120 nm. The highest cellular uptake is observed in the case of Zr-based MOFs with a diameter of 40 nm (PU₄₀ MOFs). Moreover, doxorubicin can be loaded into the inner pores of PU₄₀ MOF via π-π and electrostatic interactions (DPU₄₀ MOFs), with a loading capacity of 82 wt%, and gradually released under acidic conditions. In vitro, the resulting DPU₄₀ MOFs can be internalized by cancer cells more effectively, thereby enhancing the delivery of doxorubicin into cancer cells. Ultimately, this results in enhanced antitumor efficacy toward 4T1, Hs 578T, and MCF-7 cells. Our findings indicate that approximately 40 nm may be the optimum diameter for the special Zr-based MOFs to be internalized by cells more effectively, providing potent potential nanocarriers for drug delivery. Full article