Ordered Large‐Pore MesoMOFs Based on Synergistic Effects of TriBlock Polymer and Hofmeister Ion

Coordination-Driven Templated Synthesis of Hierarchically Porous Zeolitic Imidazolate Frameworks for Cascade Enzyme Cycle Amplification Coupled Immunoassay

Although hierarchically porous zeolitic imidazolate frameworks (HPZIFs) not only inherit the intrinsic architectural and chemical stabilities of their microporous counterparts but also afford open space for the efficient mass diffusion of the macromolecules involved, their rational design and construction are still challenging. Herein, HPZIFs with tailorable pore sizes ranging from 18 to 54 nm were successfully fabricated by using a newly developed soft-template-directed strategy. Our success rooted in the fact that the screened PS81-PVP44-PEO113 triblock copolymer could effectively coordinate with the metal precursor for the directed crystallization of ZIFs along surfactant assemblies. The advantages of continuous large pores and open structures in such HPZIFs were fully taken into account to serve as a bioreactor for the efficient immunoassay. The expanded large pores provided not only a significantly vast surface area to enhance the density of capture antibodies but also enough space for accommodating multiple conjugated biomolecules in one pore channel. In combination with a cascade enzyme cycle amplification strategy, a model biomarker of prostate-specific antigen (PSA) at the femtomolar level was checked with a limit of detection of 92 fM using the developed immunosensor. Specific screening on patients with prostate cancer or even benign prostatic hyperplasia was exemplified through accurately quantifying small changes of PSA concentration in clinical serum samples, prefiguring the great potential of the developed HPZIF-8 immunosensor platform for the early monitoring and diagnostics of diseases.

Recent Advances in Multifunctional Reticular Framework Nanoparticles: A Paradigm Shift in Materials Science Road to a Structured Future

Porous organic frameworks (POFs) have become a highly sought-after research domain that offers a promising avenue for developing cutting-edge nanostructured materials, both in their pristine state and when subjected to various chemical and structural modifications. Metal-organic frameworks, covalent organic frameworks, and hydrogen-bonded organic frameworks are examples of these emerging materials that have gained significant attention due to their unique properties, such as high crystallinity, intrinsic porosity, unique structural regularity, diverse functionality, design flexibility, and outstanding stability. This review provides an overview of the state-of-the-art research on base-stable POFs, emphasizing the distinct pros and cons of reticular framework nanoparticles compared to other types of nanocluster materials. Thereafter, the review highlights the unique opportunity to produce multifunctional tailoring nanoparticles to meet specific application requirements. It is recommended that this potential for creating customized nanoparticles should be the driving force behind future synthesis efforts to tap the full potential of this multifaceted material category.

Polyoxometalate-Bridged Synthesis of Superstructured Mesoporous Polymers and Their Derivatives for Sodium-Iodine Batteries

Despite the impressive progress in mesoporous materials over past decades, for those precursors having no well-matched interactions with soft templates, there are still obstacles to be guided for mesoporous structure via soft-template strategies. Here, a polyoxometalate-assisted co-assembly route is proposed for controllable construction of superstructured mesoporous materials by introducing polyoxometalates as bifunctional bridge units, which weakens the self-nucleation tendency of the precursor through coordination interactions and simultaneously connects the template through the induced dipole-dipole interaction. By this strategy, a series of meso-structured polymers, featuring highly open radial mesopores and dendritic pore walls composed of continuous interwoven nanosheets can be facilely obtained. Further carbonization gave rise to nitrogen-doped hierarchical mesoporous carbon decorated uniformly with ultrafine γ-Mo₂ N nanoparticles. Density functional theory proves that nitrogen-doped carbon and γ-Mo₂ N can strongly adsorb polyiodide ions, which effectively alleviate polyiodide dissolving in organic electrolytes. Thereby, as the cathode materials for sodium-iodine batteries, the I₂ -loaded carbonaceous composite shows a high specific capacity (235 mA h g^-1 at 0.5 A g^-1 ), excellent rate performance, and cycle stability. This work will open a new venue for controllable synthesis of new hierarchical mesoporous functional materials, and thus promote their applications toward diverse fields.

Metal Organic Framework Cubosomes

We demonstrate a general strategy for the synthesis of ordered bicontinuous-structured metal organic frameworks (MOFs) by using polymer cubosomes (PCs) with a double primitive structure (Im 3 ‾ ${\bar{3}}$ m symmetry) as the template. The filling of MOF precursors in the open channel of PCs, followed by their coordination and removal of the template, generates MOF cubosomes with a single primitive topology (Pm 3 ‾ ${\bar{3}}$ m) and average mesopore diameters of 60-65 nm. Mechanism study reveals that the formation of ZIF-8 cubosomes undergoes a new MOF growth process, which involves the formation of individual MOF seeds in the template, their growth and eventual fusion into the cubosomes. Their growth kinetics follows the Avrami equation with an Avrami exponent of n=3 and a growth rate of k=1.33×10^-4 , indicating their fast 3D heterogeneous growth mode. Serving as a bioreactor, the ZIF-8 cubosomes show high loading of trypsin enzyme, leading to a high catalytic activity in the proteolysis of bovine serum albumin.

Photodynamic and Its Concomitant Ion-Interference Synergistic Therapies Based on Functional Hierarchically Mesoporous MOFs

Although ion-interference therapy (IIT) has become an intriguing option for cancer treatment, the generation of interference ions on-demand remains a challenge. Herein, a nanoplatform based on hierarchically mesoporous metal-organic frameworks (HMMOFs) is adopted to integrate black phosphorus quantum dots (BPQDs) and meso-tetra(4-carboxyphenyl) porphine (TCPP) to realize controllable phosphate anions (PAs) production in a specific cancerous region for IIT. The uniform large mesopores of HMMOFs could guarantee the selective screening and immobilization of ultra-small and monodispersed BPQDs. The TCPP in microporous domains of HMMOFs could effectively produce ¹ O₂ , which not only serves as photosensitizer for photodynamic therapy (PDT), but also switches on the release of PAs from BPQDs in the adjacent mesoporous domains to trigger the concomitant synergetic IIT. The elaborated nanoplatform (BP@HMUiO-66-TCPP) presents good biocompatibility, biodegradability as well as enhanced synergetic therapeutic effects. In murine models treated with BP@HMUiO-66-TCPP, the tumor inhibition rate is as high as ≈98.24% as compared to that of the control group after 14 days treatment. Moreover, the tumor volumes in the synergetic group are only 19.6% of those in the PDT alone treated group. Such a concept of exogenous photo-controlled synergistic therapeutics might be extended to a broad range of IIT for an improved antitumor efficacy.

Bimetallic Ordered Large-Pore MesoMOFs for Simultaneous Enrichment and Dephosphorylation of Phosphopeptides

Despite the fact that bimetallic metal-organic frameworks (MOFs) could afford multiple functionalities by a synergistic effect of individual metallic centers, their intrinsic microporous structure frequently restricts their wide applications with bulky molecules involved. An urgent need is consequently triggered to design bimetallic hierarchical mesoporous MOFs (mesoMOFs). Herein, Zr/Ce mesoMOFs with a uniform pore size of up to 8 nm was successfully synthesized by a copolymer template strategy with the aid of a Hoffmeister ion. The obtained Zr/Ce mesoMOFs feature high porosity, good chemical and thermal stabilities, and tunable element components, and up to 70% Zr could be incorporated into the mesoporous Ce-based framework without deteriorating its crystallinity. Thanks to the synergistic effect of inherent Ce and Zr as well as the large and open pore channels, a broad range of phosphopeptides with different molecule sizes could be effectively checked out, thanks to their simultaneous enrichment and dephosphorylation capabilities. Such an ability to efficiently concentrate phosphopeptides remained intact even in the presence of abundant non-phosphorylated species. The practical detection of phosphopeptides from human serum was also verified, prefiguring the great potentials of bimetallic large-pore mesoMOFs for the proteome applications.

Tailoring Nanoporous-Engineered Sponge Fiber Molecular Sieves with Ternary-Nested Architecture for Precise Molecular Separation

Polymeric fiber molecular sieves (PFMs) with ultrahigh surface areas, well-defined Murray's-law hierarchical nanoporous structures, and superior self-standing properties are of great interest for molecular-level separation applications. However, creating such PFMs has been proven extremely challenging. Herein, we report a cross-scale pore-forming strategy to create intriguing sponge fiber molecular sieves with hierarchical, tailorable, and molecularly defined nanoporosity by nanospace-confined chain-packing modulation at the molecular level. Robust secondary ultramicropores (<7 Å) and micropores (<2 nm) are in situ constructed in the macro/mesoporous skeletons of sponge fibers to realize a tunable pore size distribution. The resultant PFMs exhibit the integrated properties of ultrahigh surface area (860 m² g^-1), large pore volume (0.6 cm³ g^-1), self-standing properties, and excellent molecular sieving performance and are widely applied in acetophenone/phenyl ethanol separation, hydrogen peroxide purification, ethyl acetate separation, and CO₂ adsorption fields. The fabrication of such PFMs provides a feasible way for the design and development of polymeric fibrous sieves for molecular separation in large-scale chemical, energy, and environmental operation processes.

The chemistry of Ce-based metal-organic frameworks

Metal-organic frameworks (MOFs) have gained widespread attention due to their modular construction that allows the tuning of their properties. Within this vast class of compounds, metal carboxylates containing tri- and tetravalent metal ions have been in the focus of many studies due to their often high thermal and chemical stabilities. Cerium has a rich chemistry, which depends strongly on its oxidation state. Ce(iii) exhibits properties typically observed for rare earth elements, while Ce(iv) is mostly known for its oxidation behaviour. In MOF chemistry this is reflected in their unique optical and catalytic properties. The synthetic parameters for Ce(iii)- and Ce(iv)-MOFs also differ substantially and conditions must be chosen to prevent reduction of Ce(iv) for the formation of the latter. Ce(iii)-MOFs are usually reported in comprehensive studies together with those constructed with other RE elements and normally they are isostructural. They exhibit a greater structural diversity, which is reflected in the larger variety of inorganic building units. In contrast, the synthesis conditions of Ce(iv)-MOFs were only recently (2015) established. These lead selectively to hexanuclear Ce-O clusters that are well-known for Zr-MOFs and therefore very similar structural and isoreticluar chemistry is found. Hence Ce(iv)-MOFs exhibit often high porosity, while only a few porous Ce(iii)-MOFs have been described. Some of these show structural flexibility which makes them interesting for separation processes. For Ce(iv)-MOFs the redox properties are most relevant. Thus, they are intensively discussed for catalytic, photocatalytic and sensing applications. In this perspective, the synthesis, structural chemistry and properties of Ce-MOFs are summarized.