Highly ordered structure and persistent stability of covalent organic frameworks (COFs) make them promising supports for metal-based catalysts, yet the influence of framework regulation and nucleation sites on catalytic performance remains underexplored. Here, three COFs were constructed using a triazine-based core and O,N-chelating linkers with varying heteroatom content, yielding ordered two-dimensional structures with good stability and porosity. Subsequently, cobalt nanoparticles were uniformly loaded onto these COFs via a double-solvent method to form Co@COF composites. Among them, Co@THz20 exhibited the best performance under the optimal reaction conditions, achieving 99.33% reduction of 4-nitrophenol within 5 minutes (TOF = 0.25 min−1) and maintaining high activity over six cycles. Kinetic studies verified that the reaction followed a pseudo-first-order kinetic model, and an apparent rate constant of 1.17 min−1 was obtained. Thermodynamic analysis indicated that the reaction has good feasibility within the range of 303.15 K–323.15 K. Mechanistic analysis revealed that cobalt exists mainly as hydroxide on the COF surface, with hydrazone moieties in TPTTHz forming strong interactions that anchor cobalt species and facilitate electron transfer. This work highlights the potential of N,O-rich COFs as effective supports for composite catalysts in the green and efficient reduction of p-nitrophenol.

In recent years, cyclic cyclophosphazene polycarboxylate ligands have been widely applied in the synthesis of metal-organic frameworks (MOFs) due to their coordination number and topological diversity, thermal stability and functional integration. Here, Zn-DPCP was designed and synthesized firstly by the reaction of Zn(NO3)2·6H2O and hexakis(3,5-dicarboxylatephenyloxy)-cyclotriphosphazene (H12DPCP). Structural analysis revealed that the 3D framework of Zn-DPCP consists of two distinct secondary building units (Zn3O4(COO)5 and Zn2O2(COO)2), which collaboratively define its unique luminescent behavior. This architecture endows the MOF with dual functionality: selective detection of nitroaromatic compounds (NACs) and actinide ions (Th4+/UO22+) in aqueous media. Specifically, the LODs for TNP, Th4+, and UO22+ are as low as 2.09 nM, 2.74 nM, and 3.87 nM, respectively. Furthermore, a novel composite membrane material (Zn-DPCP@PVA) was successfully fabricated by incorporating Zn-DPCP into a polyvinyl alcohol (PVA) matrix. This material maintains the exceptional sensing capabilities of the parent MOF, demonstrating sensitive detection of 2,4,6-trinitrophenol, Th4+, and UO22+, while significantly enhancing the processability and practical applicability of MOF-based sensors.

A cadmium-based metal-organic framework (denoted as Cd-DPCP) with a three-dimensional porous structure was successfully designed and synthesized using hexakis(3,5-dicarboxylatephenyloxy)-cyclotriphosphazene (H12DPCP) as the organic linker and Cd(NO3)(2)center dot 4H(2)O as the metal source. Notably, Cd-DPCP exhibits excellent multifunctional luminescent sensing performance, capable of efficiently detecting harmful ions (UO22+, Th4+, and Cr2O72-) and pesticide molecules with high reusability rates. The fluorescence response mechanism was systematically investigated through powder X-ray diffraction, ultraviolet-visible absorption and fluorescence spectroscopy, together with theoretical calculations performed using Gaussian. Experimental results reveal that the fluorescence quenching of Cd-DPCP toward harmful ions is dominated by competitive absorption, whereas its fluorescence enhancement in the presence of pesticide molecules is primarily attributed to photoinduced electron transfer. These findings suggest that Cd-DPCP holds great promise as a multifunctional luminescent sensor for detecting hazardous substances in environments.

Two Co-based NDI complexes, [Co(OXA)(DPNDI)]center dot 2DMF center dot H2O (complex 1) and [Co3(PTA)3(DPNDI)(DMF)2]center dot 6DMF (complex 2) (DPNDI=N,N'-di(4-pyridyl)-1,4,5,8-naphthalenetetracarboxydiimide, OXA= o-phthalic acid, PTA= p-phthalic acid), were synthesized and characterized by the mixed ligand strategy. Structural analysis showed that the packing structure of complex 1 was assembled with central metal cobalt connected by DPNDI and OXA, forming a two-dimensional structure. Due to the difference of phenyl polycarboxylic acid pillared supporting ligand, complex 2 featured a three-dimensional supramolecular network structure. Furthermore, it is found that under the synergistic action of hydrogen peroxide (H2O2), the two complexes showed good photocatalytic degradation activity for five organic dyes under visible light irradiation, and the degradation rates of complex 2 for MB, Eosin and Rbs exceeded 90 % within 100 min. It is worth noting that complex 1 can also be used as a catalyst for reducing p-nitrophenol to p-aminophenol. The strategy on controlling dimensions of complexes via rational design of co-ligand geometry is researched, and their structure-activity relationships have also been investigated to enrich the exploration of Co-based MOFs for potential application in catalysis.

Tetraphenylethane (TPE)-based metal-organic frameworks (MOFs), due to its excellent fluorescence properties, have received widespread attention in fluorescence sensing and white light-emitting diodes. In this work, starting from the widely used AIE linker 4',4''',4''''',4'''''''-(ethene-1,1,2,2-tetrayl)tetrakis(([1,1'-biphenyl]-4-carbox-ylic acid)) H4TCBPE, a cyan-light emitted TPE-based MOF (H3O & sdot;[Y(TCBPE)(H2O)2]& sdot;1.5H2O, complex 1) was prepared. Complex 1 possessed a porous two-dimensional network structure with supporting TPE polycarboxylate and the-COOH groups of which were totally deprotonated. The fluorescence of complex 1 was tuned via the incorporation of rhodamine B (RhB) to afford a composite material RhB@1, and white light emission with the CIE coordinate of (0.31,0.33) was achieved when the molar ratio of dye and ligand for preparing RhB@1 was fixed at 7:1. Moreover, both complex 1 and composite RhB@1 could realize fluorescent sensing for nitro compounds, and it is found that the incorporation of RhB effectively improved the sensing ability of complex 1. Notably, in the presence of RhB, we accidentally obtained a new TPE-based MOF ((CH3)2NH2 & sdot;[Y(HTCBPE)(DMF) (HCOO)]& sdot;3DMF, complex 2) in possession of a different topology with the-COOH groups in ligand partially coordinated. Such RhB assistant fluorescent and topological modulation of TPE-based MOFs may provide a new idea for achieving diverse topological structures of MOFs as well as tuning the fluorescent properties.

Smart metal-organic framework (MOF) chromic materials that respond to chemical or electrical stimuli are highly desirable for daily life and optoelectronic applications. Three novel MOFs: [Mn(H2NDISA)(DMF)2] (1), [Zn(H2NDISA)(DMF)2] (2), and [Cd(H2NDISA)(DMF)2] (3) are first synthesized and characterized, based on a H4NDISA ligand (H4NDISA (N,N'-bis(3-carboxy-4-hydroxyphenyl)-1,4,5,8-naphthalenetetradicarboximide)) with free hydroxyl active sites. Structural analysis reveals that complexes 1-3 display a 3D supramolecular network, a 2D layered structure, and a 1D chain structure, respectively, because of different intermolecular interactions, affording them with dimension-dependent multistimulus-responsive chromism behaviors. Alkali metal ion-induced chromism is related to topological structures of the complexes, as well as the type and concentration of ions. Regarding alkaline earth metal ions, complexes 1-3 change from yellow to red in Be2+. As for fourth-period transition-metal ions, complexes 1-3 display deep red and brown colors in Fe3+ and Cu2+, respectively, rendering these complexes as selective and sensitive visual ion detectors when fabricated as portable polyvinylidene difluoride-polyethylene glycol@1-3 films (PVDF-PEG@1-3 films). Furthermore, complexes 1-3 exhibit electrochromic switching properties, and chromic voltages are related to dimension of MOFs, which may provide proof-of-concept for low-energy electrochromic applications. This study might enrich the potential application of naphthalenediimide-based MOF materials in cation detection and optoelectronic devices.

The highly ordered architectures and intrinsic stability of covalent organic frameworks (COFs) make them promising supports for metal-based catalysts, but the effects of framework regulation and linker-defined nucleation sites on catalytic performance remain insufficiently understood. Herein, three COFs were synthesized from a triazine-based building block and O,N-chelating linkers with different heteroatom contents, yielding ordered two-dimensional frameworks with satisfactory structural stability. Subsequently, cobalt species were introduced into these COF supports via a double-solvent method to obtain Co@COF composites. Among the obtained composites, Co@THz20 showed the highest catalytic activity under the optimized conditions, achieving 99.33% conversion of 4-nitrophenol within 5 min (TOF = 0.25 min-1) and retaining appreciable activity during six consecutive runs. Kinetic analysis suggested that the reaction behavior was consistent with a pseudo-firstorder model under excess KBH4 conditions, giving an apparent rate constant of 1.17 min-1. Temperaturedependent kinetic analysis indicated that Co@THz20 remained catalytically active between 303.15 and 323.15 K, and the derived activation parameters provided further insight into the apparent energy barrier of the reduction process. XPS and HR-TEM results of Co@THz20 are consistent with the presence of surfacehydroxylated cobalt species with Co(OH)2-like features. These Co species may participate in BH4- activation and interfacial electron transfer, while the hydrazone moieties in TPTTHz likely provide additional coordination sites for cobalt immobilization. This work provides insight into the role of linker-defined chelating microenvironments and highlights the potential of N,O-rich COFs as supports for cobalt-based composite catalysts for the efficient borohydride-assisted reduction of p-nitrophenol.

Erythromycin (ERY) residues have emerged as a critical global concern to food safety and environmental security in recent years. Detecting ERY in food and environment is important for safeguarding public health. In this study, a metal-organic framework [Me2NH2][Eu(TCBPEF)(HCOO)(DMF)]·2.5DMF Eu-TCBPEF, H4TCBPEF = 4',4‴,4‴″,4‴″″-(ethene-1,1,2,2-tetrayl)tetrakis(3-fluoro-[1,1'-biphenyl]-4-carboxylic acid) was synthesized and utilized as a fluorescence "turn-on" sensor for real-time visual monitoring of ERY, which demonstrated the first TPE-based MOF for ERY detection. Eu-TCBPEF could selectively detect ERY in water with a limit of detection (LOD) of 0.327 μM and exhibited excellent detection performance for ERY in seawater and chicken samples with good recovery percentage ranging from 96.9% to 105.4%. Furthermore, a portable Eu-TCBPEF@PVA was fabricated, enabling real-time and on-site monitoring of ERY in combination with a smartphone-assisted platform. In addition, Eu-TCBPEF exhibited a remarkable mechanofluorochromism: the fluorescent color can be reversibly switched between cyan and yellow upon grinding and exposure to acetonitrile. This study presents a dual-function MOF that provides new insights into the function of TPE-based MOFs and meanwhile offers an effective solution for on-site monitoring of antibiotic residues in food and environment, with promising applications in advanced anticounterfeiting security materials.

A 5-amino-2-hydroxybenzoic acid-modified triazine polycarboxylate metal-organic framework [Cd(ODTBBA)] 5DMF3H2O (Compound 1) has been successfully designed and synthesized based on the triazine poly(carboxylic acid) ligand ODTBBA (5,5 '-((6-oxo-1,6-dihydro-1,3,5-triazine-2,4-diyl)bis(azanediyl))bis(2-hydroxybenzoic acid)) and the transition metal source Cd(NO3)24H2O through the solvothermal method. Compound 1 featured a three-dimensional network structure constructed by the interconnection and interpenetration of Cd-O/N polyhedron and the ligand ODTBBA. Due to the instability of the compound in water and ethanol, we propose a new strategy of stabilizing metal organic frameworks using polymer materials; the complex was mixed into polyvinylidene fluoride for the preparation of Cd-MOF film material. The experimental results showed that the Cd-MOF film material with compound 1 has excellent metal framework stability and fluorescence properties. Therefore, we explored its fluorescence sensing properties. The Cd-MOF film material exhibits sensitive fluorescence responses to nitroaromatic compounds (nitro aromatic compounds) as well as heavy metal cations and anions (Cu2+, Fe3+, and Cr2O7 2-) and can achieve visual sensing of the three heavy metal ions through distinct color changes from pale yellow to dark yellow or black.

With the escalating environmental concerns arising from Fe3+ and UO22+ contamination in industrial and nuclear wastewater, the development of efficient, sensitive, and portable detection technologies is of paramount importance. In this work, a novel zinc-based metal-organic framework (MOF), Zn-HTA-Bipy, was successfully synthesized via hydrothermal method using 2-hydroxyterephthalic acid (HTA) and 2,2’-Bipyridine (2,2’-Bipy) as dual ligands. This Zn-HTA-Bipy exhibits dual-functional sensing capabilities, highly selective and sensitive fluorescence quenching responses toward both Fe3+ and UO22+ ions. Based on the fluorescence response, it is found that Zn-HTA-Bipy features a distinct Fe3+-induced ionochromic behavior, fluorescence signal transitioning from white to purple. Mechanistic investigations indicate that the fluorescence quenching mechanism of Zn-HTA-Bipy for Fe3+ and UO22+ is a synergistic process dominated by static quenching, accompanied by energy competitive absorption effect. To boost its practical applicability for on-site detection, a PVDF-PEG@Zn-HTA-Bipy mixed-matrix membrane (MMM) was fabricated by immobilizing Zn-HTA-Bipy into a PVDF-PEG composite matrix through a combined phase inversion and solution casting method. It enables both sensitive fluorescent detection and intuitive colorimetric estimation of Fe3+, serving as a reliable portable platform for on-site monitoring of Fe3+ in mining wastewater. Collectively, this study provides a high-performance dual-target fluorescent probe and offers a feasible strategy for advancing the practical application of MOF-based sensing membrane materials in environmental pollution control.

Low-symmetry tetraphenylethylene (TPE) ligands hold great promise for constructing metal-organic frameworks (MOFs) with previously inaccessible architectures and multi-stimuli-responsive properties. Herein, we developed a novel calcium-based MOF (Ca-m-ETTC) from the meta-carboxyl-substituted TPE-based ligand 4′,4‴,4‴'',4‴''''-(ethene-1,1,2,2-tetrayl)tetrakis(([1,1′-biphenyl]-3-carboxylic acid)) (m-H4ETTC), exhibiting distinct fluorescence color changes (cyan to yellow-green) in response to temperature, pH, mechanical force, and HCl vapor. Ca-m-ETTC adopted a two-dimensional (2D) structure featuring low porosity (3.1%) and extensive intramolecular hydrogen bonding, restricting the ligand in a twisted conformation and meanwhile contributing to exceptional fluorescence stability in diverse solvents. Specially, Ca-m-ETTC demonstrated a selective fluorescence response to 35% HCl vapor with a rapid 2.86-fold fluorescence enhancement and a pronounced red shift of emission peak (∼31 nm) over other volatile vapors and hydrogen halides. Detailed experimental investigations revealed an underlying mechanism involving the AIE effect caused by the partial release of ligand moiety, as well as the restriction of intramolecular motion within the pores. Furthermore, we have fabricated a bifunctional paper-based material of Ca-m-ETTC, enabling dual-mode information encryption and the rapid visual monitoring of HCl vapor (<5s). This study will not only enrich the family of TPE-based MOFs for multi-stimuli-responsive applications, but also offer new insights for designing gas-sensing MOFs.

Viologen-encapsulated metal-organic frameworks (MOFs) have attracted significant interest owing to their responsiveness to multiple external stimuli, which enhances their potential applications in sensing and environmental monitoring. Here, we synthesized the novel viologen-encapsulated Ho-MOF material (pbpy)·[Ho2(NH2-BDC)4(H2O)]·3H2O (complex 1) via an in situ method using 2-aminoterephthalic acid (NH2-H2BDC) and the viologen derivative dichloro-1,1'-(1,4-benzylidene)-di(4,4'-bipyridine) (pbpy·2Cl), along with the control material [Ho4(NH2-BDC)5(DMA)2(μ3-OH)2]·3H2O (complex 2) without a viologen for comparison. Complex 1 exhibited dual detection capability for Th(IV) and nitroaromatic compounds (NACs), demonstrating significant advantages in sensing performance compared to complex 2. These results highlight the critical role of viologen incorporation in improving sensor functionality. Moreover, we prepared a MOF-based PVDF composite film material capable of rapidly detecting Th(IV) and NACs, demonstrating potential for practical sensing applications. In addition, thanks to the presence of a viologen inside the channels, complex 1 could achieve rapid and visual detection of N2H4·H2O. EPR results indicate that the color change is due to the generation of viologen radicals. These properties make the material a promising candidate for multianalyte detection, advancing the development of multistimulus responsive materials.

The development of TNP sensors for one-stop real-time detection is crucial for understanding water environments and maintaining human health and safety. However, one of the main obstacles that hindering the development of on-site detection technology in the future is the complexity of the detection environment. Here, in this work, a novel metal-organic framework (MOF) Eu-tcbpe designed with H4tcbpe (H4tcbpe=4',4''',4''''',4'''''''-(ethene-1,1,2,2-tetrayl)tetrakis(([1,1'biphenyl]-4-carboxylic acid))) and Eu3+ was synthesized. This complex exhibited anti-interference, sensitive, and rapid detection capabilities with the limitation of detection of 0.42 mg/L for TNP. In order to realize real-time portable detection, a hydrogel sensing platform with Eu-tcbpe and methyl red was designed and prepared. This platform retains all the features of Eu-tcbpe. Combining it with smartphone can perform real-time detection towards TNP. It could be found that two independent colorimetric and fluorescent channels on the sensor exhibited specific responses to TNP under sunlight and fluorescence irradiation, respectively. Furthermore, by utilizing the principle of strong electrostatic interaction, the cationic dye safranin T (ST) was encapsulated into Eu-tcbpe with an anionic framework, achieving tunability of the fluorescence color of Eu-tcbpe. This work is expected to provide research ideas for advancing the detection of MOFs in fluorescence sensing and the practical application of MOFs as multi-color luminescent materials.

To achieve rapid and efficient detection of residual antibiotics in the environment and food, and to overcome the numerous drawbacks of traditional detection methods, N,N '-Di(4-pyridyl)-1,4,5,8-naphthalenetetracarboxylic diimide (DPNDI) was used as the ligand and Zn(NO3)2 center dot 6H2O as the metal source to synthesize a threedimensional porous metal-organic framework [Zn(PDNDI)]center dot 3H2O (Zn-PDNDI) via solvothermal reaction, where H2PDNDI = N-(4-pyridyl)-4,5-dicarboxy-1,8-naphthalenediimide. Fluorescence sensing indicates that in aqueous media Zn-PDNDI shows a specific fluorescence enhancement response toward ciprofloxacin (CIP), while it exhibits obvious fluorescence quenching toward ornidazole (ONZ), doxycycline (DOX) and metronidazole (MTZ). Zn-PDNDI exhibits high selectivity and sensitivity in the fluorescent detection of various antibiotics. In addition, through comprehensive experimental results and theoretical calculations, it was revealed that ZnPDNDI exhibits "turn on/off" behavior caused by energy competitive absorption mechanisms and intermolecular interactions. The HPLC method was used to verify that the fluorescence sensing method developed in this study can detect CIP and ONZ. Zn-PDNDI lays the experimental foundation for the design and development of NDI-based multi-channel MOF fluorescent sensors, showing significant application potential in the fields of food safety and environmental monitoring

La-MOF complex with six metal cores was synthesized by an in situ reaction of terephthaloyl chloride and La(NO3)3 & centerdot;6H2O under solvothermal conditions. During the reaction process, it was surprisingly found that the terephthaloyl chloride was hydrolyzed into 1,4-H2BDC and then coordinated with La(NO3)3 & centerdot;6H2O to form a six-core metal-organic framework, complex 1, [La6(1,4-BDC)9(mu-H2O)(H2O)(DMF)6]& centerdot;H2O & centerdot;3DMF, which was constructed by two 4-centered building blocks [La4(COO)10] and [La4(COO)10(mu-H2O)] and the ligand 1,4-BDC2-. Complex 1 was characterized by infrared spectroscopy (IR), fluorescence spectra, thermogravimetric (TG) analysis, PXRD, and UV-vis spectra, etc. Moreover, a fluorescence sensing experiment was carried out with complex 1 to detect harmful substances (TNP, DNP, ONP, Fe3+, and Cr2O7 2-). The results indicate that the fluorescence intensity can be reduced to varying degrees by five kinds of detection compounds. Especially, the fluorescence quenching constant K SV of complex 1 for TNP detection is as high as 1.18 & times; 105 M-1. In the above fluorescence sensing experiment, it was found that the detection wavelength in the ultraviolet region was due to the contribution of the ligand, which is not conducive to future practical applications. Therefore, we successfully prepared another two complexes (2 and 3) containing rare earth elements europium and terbium by regulating the ligand and rare earth ions. The experimental results showed that complexes 2 and 3 also have detection effects on the five harmful substances mentioned above. However, their detection wavelengths have undergone a significant redshift, which is more advantageous for future visual fluorescence detection.

The efficient capture of radioactive iodine is critical for both the sustainable development of nuclear energy and environmental safety. Physical adsorption-type materials have attached widespread attention due to their excellent regenerative capabilities and low energy consumption. Based on idea above, we utilized an asymmetric triazine hexacarboxylic acid with diverse linking fashions as linker and non-toxic alkali earth metals as metal sources to construct two novel alkaline earth metal-organic framework (MOFs) featuring three-dimensional porous topological network: Mg2(H2BATD) (DMF)2 (1); and [Ca2(H4BATD) (H2O)4]·(OH)2·3DMF (2) in this work. (H6BATD = 5,5'-(6-biscarboxymethylamino-1,3,5-triazine-2,4-diyl)bis (azadiyl). The materials were characterized using elemental analysis, infrared spectroscopy, ultraviolet spectroscopy, PXRD, and thermogravimetric analysis. Additionally, considering the three-dimensional porous network structure and multiple carboxylate adsorption sites of the asymmetric triazine hexacarboxylic acid series complexes, the adsorption performance of the complexes toward iodine in cyclohexane were explored, and the adsorption mechanism was investigated. The complex exhibits good adsorption performance for elemental iodine in cyclohexane solution and maintains a high adsorption rate under recycling use. Comprehensive characterization and structural analysis confirm that adsorption is a surface chemisorption process. The density functional theory (DFT) calculations were conducted to explore the adsorption sites of iodine on two MOF materials and the reasons for their performance differences. Therefore, the design of diverse triazine carboxylic acid-based MOFs to regulate the pore structure provides a promising strategy for achieving efficient capture of radioactive iodine.

Imbalance in the levels of ascorbic acid (AA) can pose a risk to human health. Therefore, it's essential to establish an accurate method for the detection of AA. In this work, a novel N-doped carbon composite (MnOx@NC) with dual enzyme-like activities to detect AA was prepared by calcination of Mn-MOF containing H3TTPCA ligand. Interestingly, the center dot O2- that leads to its oxidase-like activity was not formed by dissolved oxygen, but came from the synergistic effect of lattice oxygen generated by calcination and the transformation of MnII/MnIII/MnIV, and the presence of H2O2 provided much center dot OH, which caused its peroxidase-like activity. Meanwhile, the residual N element came from H3TTPCA ligand assisted the catalytic process. Accordingly, a dual-signal sensing platform and smartphone-assisted recognition for detection of AA was developed and a colorimetric sensor array was established to distinguish three antioxidants. This work also demonstrates considerable promise for the detection of AA in authentic pharmaceuticals.

Phenols and iodine are two harmful substances that pose a risk to human health, including skin irritation, respiratory irritation, endocrine disruption, and potential carcinogenic risks. Therefore, the fluorescence recognition of phenols and adsorption of iodine become particularly important. Herein, a novel luminescent bimetallic organic framework cage (1) and post-modified material PVDF-PEG@1 film were prepared. Compound [Zn3.1Co0.4(DPOT)(H2O)5.5]center dot NO3 center dot 5H2O center dot DMA (1) was constructed by the large size ligand H6DPOT (5, 5 ', 5 ''-((1, 3, 5-triazine-2, 4, 6-triyl) tris(oxy)) tri-isophthalic acid) and coordinated with the transition metal ions of Zn2+ and Co2+. Based on the excellent fluorescence properties of 1, it was used for fluorescence sensing of toxic phenols. The results of fluorescence sensing phenols experiments exhibited that compound 1 had the best fluorescence turn-off effect for TNP (2, 4, 6-trinitrophenol), PNP (p-nitrophenol), and DNP (2, 4-dinitrophenol). The calculation results show limit of detection (LOD) values for three phenols as low as 0.78, 1.26, and 1.48 mu M, respectively. Interestingly, compound 1 presented a significant fluorescence turn-on for HQ (hydroquinone), and the LOD value is 1.80 mu M. In addition, based on the advantage of large pore size in compound 1, PVDF-PEG@1 film was fabricated for iodine adsorption. Specifically, PVDF-PEG@1 film shows outstanding adsorption performance. The results indicate that the PVDF-PEG@1 film can adsorb iodine to reach 2.40 g/g.

Lanthanide organic framework material (Ln-MOF) constructed from rare earth elements have unique spatial structure and photoluminescence properties, which can be used in drug delivery, near-infrared and white light emission, fluorescent probes, gas storage and separation. In this work, nitrogen-containing triazine heterocyclic polycarboxylic acid ligand, 2,4,6-tris(3,5-dicarboxylphenylamino)-1,3,5-triazine (H6TDPAT) was selected as a multidentate chelating ligand, the rare earth metal erbium (Er) as the central metal source, a novel Er-TDPAT, (H3O)2‧[Er2(TDPAT)4/3‧(μ2-H2O)]‧5H2O‧4DMA, was synthesized under the solvothermal conditions. The structural analysis shown that the Er-TDPAT framework is constructed by Er-O polyhedral cages with the linking ligand, which are stacked with each other to form a three-dimensional porous structure. Based on its excellent fluorescence properties, it is necessary to explore the fluorescence sensing capability of the complexes for metal cations, anions and Vitamin. Experimental result show that this compound has potential fluorescence sensing properties for Fe3+, Cr2O72− and Vitamin B1 (VB1). At the same time, their sensing mechanisms were also studied. It is laying the foundation for establishing a new fluorescence sensing platform in the future.

We have successfully synthesized two novel terbium-cyclophosphazene MOFs (Tb-Cpz-MOFs) featuring dual-response functionality for the first simultaneous discrimination and quantification of structurally similar third- and fourth-generation fluoroquinolone antibiotics (norfloxacin, Nor: ratiometric response; moxifloxacin, Moxi: quenching response). The two Tb-Cpz-MOFs were constructed from structurally distinct cyclophosphazene-based ligands to form a two-dimensional supramolecular network and a three-dimensional framework structure, respectively. Remarkably, the Tb-Cpz-MOFs demonstrate exceptional analytical performance, achieving detection limits of 34 nM (Nor) and 9 nM (Moxi) in spiked shrimp samples, with excellent recovery rates (96.2-105 % for Nor; 95.2-107 % for Moxi). Detailed mechanistic studies combining fluorescence spectra, UV-vis absorption, theory calculations by Vienna ab initio simulation package (VASP), and XPS analysis revealed that the ratiometric response to Nor arose from its ability to capture ligand-to-Tb3+ energy transfer, while Moxi induced fluorescence quenching through competitive light absorption with MOFs. Notably, we engineered Tb-Cpz-MOFs into field-deployable PVA films integrated with smartphone colorimetry to achieve rapid visualization of dual functional detection capabilities and on-site semi quantitative analysis. This work not only provides a reliable solution for monitoring antibiotic contamination in aquatic organisms but also establishes a general design strategy for developing advanced sensors targeting structurally similar analytes.