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Sonodynamic therapy (SDT), utilizing ultrasound (US) as the trigger, has gained popularity recently as a therapeutic approach with significant potential for treating various diseases. Metal-organic frameworks (MOFs), characterized by structural flexibility, are prominently emerging in the SDT realm as an innovative type of sonosensitizer, offering functional tunability and biocompatibility. However, due to the inherent limitations of MOFs, such as low reactivity to reactive oxygen species and challenges posed by the complex tumor microenvironment, MOF-based sonosensitizers with singular functions are unable to demonstrate the desired therapeutic efficacy and may pose risks of toxicity, limiting their biological applications to superficial tissues. MOFs generally possess distinctive crystalline structures and properties, and their controlled coordination environments provide a flexible platform for exploring structure-effect relationships and guiding the design and development of MOF-based nanomaterials to unlock their broader potential in biological fields. The primary focus of this paper is to summarize cases involving the modification of different MOF materials and the innovative strategies developed for various complex conditions. The paper outlines the diverse application areas of functionalized MOF-based sonosensitizers in tumor synergistic therapies, highlighting the extensive prospects of SDT. Additionally, challenges confronting SDT are briefly summarized to stimulate increased scientific interest in the practical application of MOFs and the successful clinical translation of SDT. Through these discussions, we strive to foster advancements that lead to early-stage clinical benefits for patients. STATEMENT OF SIGNIFICANCE: 1. An overview for the progresses in SDT explored from a novel and fundamental perspective. 2. Different modification strategies to improve the MOFs-mediated SDT efficacy are provided. 3. Guidelines for the design of multifunctional MOFs-based sonosensitizers are offered. 4. Powerful tumor ablation potential is reflected in SDT-led synergistic therapies. 5. Future challenges in the field of MOFs-based SDT in clinical translation are suggested., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

A stable nanoscaled single-excitation ratiometric luminescent pH sensor (MPDB-PCN) over a broad pH range from 2.5 to 8.6 is fabricated through post-synthetic modification of PCN-224 with naphthalimide-derived molecules. Due to the rapid, sensitive and linear response to pH, MPDB-PCN is capable of detecting 3-nitropropionic acid (3-NPA), an acid neurotoxin in food safety, with a low detection limit of 15 μM in sugarcane juice.

A porous NH 2 -MOF-76(Eu) (MOF 1) with unexpected non-luminescence was designed and synthesized. It exhibits selective fluorescence recovery for sensing dipicolinic acid (DPA), a biomarker of Bacillus anthracis. Moreover, a new europium-based MOF (MOF 2) with evident channel changes was obtained through a single-crystal to single-crystal phase transition.

Metal-organic frameworks (MOFs) have shown significant potential as photocatalysts. It has been widely assumed that all catalytic active sites within MOFs are functional in photocatalytic reactions but for a three-dimensional MOF, whether the internal catalytic active sites can effectively absorb light and actively contribute to photocatalytic reactions remains to be explored. In this context, we synthesized a two-dimensional nanosheet MOF (2D-MOF) and a three-dimensional bulk MOF (3D-MOF) composed of Zr6 clusters and tetracarboxylic porphyrin (TCPP) by the approach described in the literature. Re(bpy)(CO)3Cl (bpy = 2,2′-bipyridine), which has remarkable CO2 photoreduction ability, was introduced to the two MOFs to create two new photocatalysts 2D-MOF-Re and 3D-MOF-Re, respectively. Photocatalytic CO2 reduction experiments show that based on the equal number of catalytic active sites, the CO turnover number (TON) of 2D-MOF-Re reaches 27.8 in 6 h, which is 50 times that of 3D-MOF-Re. The result shows that certain catalytic active sites inside the bulk MOF are inactive due to the inability to absorb light. This study illuminates the potential of the dimensional reduction approach in the design of photocatalysts to exploit the capabilities fully. [ABSTRACT FROM AUTHOR]

Solar-light-driven CO2 reduction CO to CH4 and C2H6 is a complex process involving multiple elementary reactions and energy barriers. Therefore, achieving high CH4 activity and selectivity remains a significant challenge. Here, we integrate bifunctional Cu2O and Cu-MOF (MOF = metal-organic framework) core–shell co-catalysts (Cu2O@Cu-MOF) with semiconductor TiO2. Experiments and theoretical calculations demonstrate that Cu2O (Cu+ facilitates charge separation) and Cu-MOF (Cu2+ improves the CO2 adsorption and activation) in the core–shell structure have a synergistic effect on photocatalytic CO2 reduction, reducing the formation barrier of the key intermediate ⋆COOH and ⋆CHO. The photocatalyst exhibits high CH4 yield (366.0 µmol·g−1·h−1), efficient electron transfer (3283 µmol·g−1·h−1) and hydrocarbon selectivity (95.5%), which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO2 reduction reaction. This work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components. [ABSTRACT FROM AUTHOR]

Improving proton conductivity and fabricating viable metal‐organic frameworks (MOFs) based proton exchange membranes (PEMs) are central issues exploiting electrolyte MOFs. We aim to design multivariate flexibility synergistic strategy to achieve Flexible MOFs (FMOFs) with high conductivity at a wide range of humidity. In situ powder X‐ray diffraction (PXRD) and temperature‐dependent Fourier transform infrared spectra (FT‐IR) prove the synergistic self‐adaption between dynamic torsion of alkyl sulfonic acid and dynamic breathing of FMOF, forming a continuous hydrogen‐bonding networks to maintain high conductivity. Based on the convincing proton conductivity, we construct a series of long‐term durable MOF‐based PEMs that serve as a bridge between MOF and fuel cell. Consequently, the membrane electrode assembly (MEA) of the flexible PMNS1‐40 exhibits a maximum single‐cell power density of 34.76 mW cm−2 and hopefully opens doors to evaluate the practical application of proton‐conducting MOFs in direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

Herein we report two new TPE‐based 3D MOFs, that is, Sr‐ETTB and Co‐ETTB (TPE=Tetraphenylethylene, H8ETTB=4′,4′′′,4′′′′′,4′′′′′′′‐(ethene‐1,1,2,2‐tetrayl)tetrakis(([1,1′‐biphenyl]‐3,5‐dicarboxylic acid))). Through tailoring outer shell electron configurations of SrII and CoII cations, the fluorescence intensity of the MOFs is tuned from high emission to complete non‐emission. Sr‐ETTB with strong blue fluorescence shows reversible fluorescence variations in response to pressure and temperature, which is directly related to the reversible deformation of the crystal structure. In addition, non‐emissive Co‐ETTB counterpart exhibits a turn‐on fluorescent enhancement under the stimulation of analyte histidine. In the process, TPE‐cored linkers in the MOFs are released through competitive coordination substitution and subsequently reassembled to perform aggregation‐induced luminescence behavior originated from the organic linkers. [ABSTRACT FROM AUTHOR]

Herein, we present heterogeneous hollow multi‐shelled structures (HoMSs) prepared by exploiting the properties of the metal–organic framework (MOFs) casing. Through accurately controlling the transformation of MOF layer into different heterogeneous casings, we can precisely design HoMSs of SnO2@Fe2O3(MOF) and SnO2@FeOx‐C(MOF), which not only retain properties of the original SnO2‐HoMSs, but also structural information from the MOFs. Tested as anode materials in LIBs, SnO2@Fe2O3 (MOF)‐HoMSs demonstrate superior lithium‐storage capacity and cycling stability to the original SnO2‐HoMSs, which can be attributed to the topological features from the MOF casing. Making a sharp contrast to the electrodes of SnO2@Fe2O3 (particle)‐HoMSs fabricated by hydrothermal method, the capacity retention after 100 cycles for the SnO2@Fe2O3 (MOF)‐HoMSs is about eight times higher than that of the SnO2@Fe2O3 (particle)‐HoMS. A change of coat: Heterogeneous hollow multi‐shelled structures (HoMSs) are prepared by transforming the metal–organic framework (MOF)‐based coating layer into heterogeneous coatings on the surface of the original HoMSs, through a two‐step calcination process. The SnO2@Fe2O3(MOF)‐HoMSs electrodes demonstrate superior lithium‐storage capacity and cycling stability to the original SnO2‐HoMSs. [ABSTRACT FROM AUTHOR]

Two new isostructural 3D lanthanide-organic frameworks [H2N(Me)2] [Ln3(OH)(bpt)3(H2O)3] (DMF)2⋅(H2O)4 ( 1-Ln; Ln=Sm and Eu) with a 1D channel (25 Å) have been successfully assembled from the rare trinuclear [Ln3(OH)(COO)9] clusters and biphenyl-3,4′,5-tricarboxylic acid (H3bpt) and exhibit high stability towards water in the pH range 3-10. MOF 1-Eu is a promising luminescent probe for sensing Fe3+ in aqueous solution and is also selective towards rhodamine B (RhB) with a superior adsorption capacity of 735 mg g−1, which is the highest among the reported Ln-MOFs for RhB removal so far. Periodic DFT calculations further confirmed the selective adsorption of rhodamine B over other dyes. [ABSTRACT FROM AUTHOR]

Two novel lanthanide metal organic frameworks [Eu4(bpt)4(DMF)2(H2O)6]·(DMF)5·(H2O)4 (1) and [Tb4(bpt)4(DMF)2(H2O)8]·(DMF)5·(H2O)3 (2) were synthesized under hydrothermal conditions, forming a three-dimensional structure (H3bpt = biphenyl-3,4′,5-tricarboxylate). Single crystal X-ray diffraction reveals that compounds 1 and 2 are heteromorphic and have different topologies due to the change of metal ions with different radii and coordination steric hindrance. The unique luminescence properties of Eu3+ and Tb3+ ions motivated us to dope different amounts of Tb3+ into a single host to obtain light tunable materials. The tunable multicolor emissions, including red, red-orange, orange, yellow and green, can be readily achieved from the doped Ln-MOFs 3–6 by increasing the concentration of Tb3+. In addition, compounds 5 and 6 also exhibit different temperature-dependent luminescence behaviors when the concentration of Eu3+ is low, generating new Ln-MOF thermometers. [ABSTRACT FROM AUTHOR]

• Four acid-modified MOF-808 were synthesized by a post-synthesis approach. • The acidity and electron acceptor capacity of the acid groups affect B/L acidity. • Zr-808-TF has the strongest Lewis and Brønsted acidity and the highest B/L ratio. • Zr-808-TF gave 83 % GVL yield (160 °C, 8 h) in the tandem conversion of FUR to GVL. The one-pot tandem conversion of furfural (FUR) to γ-valerolactone (GVL) is desirable due to the high value of GVL and the efficiency of the synthesis process. While MOF-808 presented a good catalytic potential among Zr-MOFs, it lacked the necessary Brønsted acidity for the tandem conversion. In this study, Zr-based metal–organic framework (MOF-808) was modified with acids of different strengths (triflic acid, sulfuric acid, sulfamic acid, and trifluoroacetic acid) using a two-step post-synthesis impregnation method. EPR results revealed the appearance of coordinatively unsaturated sites of Zr (Zr-CUS) in the first step of HCl-treated Zr-808-HCl and their disappearance in the subsequent acid-modified catalysts, clarifying the impregnation process. These modified frameworks (Zr-808-TF, Zr-808-S, Zr-808-SN, and Zr-808-CF) were employed as catalysts for the tandem conversion of FUR to GVL. Zr 3d XPS and solid-state 31P MAS NMR spectra of TMPO adsorbed on the catalysts proved that Zr-808-TF outperformed other catalysts in terms of both Brønsted/Lewis acid strength and ratio. With such catalytic active sites, Zr-808-TF exhibited superior catalytic activity, achieving 83% GVL yield over an 8-hour reaction period. The four acid-modified catalysts not only differed in Lewis/Brønsted acid sites, but also exhibited different catalytic performances in the tandem conversion. The in-depth insight into the relationship between the modified functional groups and the acid-base sites provides a new avenue to optimize the acid-base sites and expands the application of MOFs in cascade catalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • WO 3 /EuMOF assembly was firstly prepared by an electrodeposition method. • The assembly was applied as a fluorescence switch. • The "on" and "off" states can be modulated by changing the voltage. • The assembled fluorescence switch exhibits good reversibility. In recent years, lanthanide metal organic frameworks have been widely used in various fields because of their excellent fluorescence properties. Fluorescence switch has also been considered as a research hot spot and widely applied in many fields. The combination of fluorescent material and electrochromic material has emerged in the preparation of fluorescence switch. Herein, a simple and rapid electrodeposition method is proposed for the preparation of amorphous EuMOF film. The whole process takes only half an hour under room temperature. The prepared amorphous EuMOF film exhibits significant emission peaks characteristic of Eu3+ when excited by 277 nm UV lamp. In addition, the prepared EuMOF is also applied in an electrochromic device to construct WO 3 /EuMOF fluorescence switch by stepwise electrodeposition using polystyrene microsphere as template. By changing the voltage, the coloring and fading of the device color, and the quenching and recovery of fluorescence can be reversibly regulated, in order to achieve the control of the "on" and "off" states of the fluorescence switch. [ABSTRACT FROM AUTHOR]

Polyoxometalate-based metal-organic frameworks (POMOFs) with bifunctional Lewis-Brønsted acid were designed by confining polyoxometalates (POMs: phosphotungstic acid (PW), phosphomolybdic acid (PMo) or silicotungstic acid (SiW)) within the Zr-MOFs. The confined POMs not only have their own Brønsted acid, but can also regulate the Lewis acid strength of the POMOFs via charge regulation, ultimately allowing the POMOFs to display superior catalytic performance in the tandem catalysis of furfural (FAL) to γ-valerolactone (GVL). Among the three catalysts (POMOF-PW, POMOF-PMo and POMOF-SiW), a complete conversion of FAL was achieved, while POMOF-PW exhibited the highest GVL yield (58.1 %) at 160 °C within 23 h. The leaching experiment and structural characterization of the catalyst before and after recycling confirmed the stability of the catalyst structure. The humin originates from the polymerization of furan ring-containing compounds driven by Brønsted acid. The adsorption configuration of the substrate molecules on the catalyst offers a new explanation for the tandem reaction process, i.e. that perpendicular adsorption performs only the first step of the tandem reaction, while the coexistence of perpendicular and horizontal adsorption permits the entire reaction process. This work gives unique insights into the tandem reaction of FAL and can guide the design of efficient tandem reaction catalysts. A synthetic strategy has been developed to construct polyoxometalate-based metal-organic framework (POMOF) with bifunctional Lewis-Brønsted acid sites by chemically confining polyoxometalates (POM) in metal-organic framework (MOF) channels. Confined POM not only endows the catalyst with Brønsted acid sites, but also enhances the acid strength of the catalyst through charge regulation, which finally promotes the catalyst to exhibit excellent catalytic performance in the multi-step cascade catalysis from furfural (FAL) to γ-valerolactone (GVL). This work also provides insight into the origin and driving sites of the by-product humin, as well as the role of the adsorption configuration in the catalytic process. A look into the future of the multi-step tandem reaction of FAL to GVL is presented. [Display omitted] [ABSTRACT FROM AUTHOR]

The transmembrane diffusion of soluble lithium polysulfides (LiPS) is the main cause of capacity loss and negative electrode corrosion in lithium-sulfur (Li-S) batteries. In order to suppress the shuttle effect of LiPS, a selective permeability membrane was constructed by introducing functional materials with negative charge groups. Herein, a functional separator with high ion conductivity is obtained by casting the environmentally friendly MOF material sulfonic acid functionalized amino-MIL-101 (S-MIL-101) onto the separator. It is found that the functionalized sulfonic acid group not only accelerates the conduction of the lithium-ion but also repels the polysulfide anion through electrostatic interactions. With this functionalized separator, the initial capacity of batteries is 1444.6 mAh·g−1 at 0.2C and remains 990.4 mAh·g−1 after 100 cycles. Meanwhile, the batteries still deliver a high initial discharge capacity of 895.7 mAh·g−1 even with the high-sulfur-loading cathode (4.7 mg cm−2) at 0.2C. We designed and synthesized sulfonic acid functionalized Al-based MIL-101-NH 2 modified separator for lithium-sulfur batteries. The introduction of sulfonic acid groups can accelerate the conduction of Li+ and carry out electrochemical processes. Besides, negatively charged sulfonic acid groups can suppress the shuttle effect through electrostatic interaction. The lithium-sulfur batteries assembled with the S-MIL-101 separator have an initial discharge capacity of 895.7 mAh·g−1 at 0.2C with 4.7 mg cm−2. [Display omitted] • S-MIL-101 improves Li+ conductivity. • Modified separators inhibit shuttle effect. • Modified separators inhibit shuttle effect. [ABSTRACT FROM AUTHOR]

• MOF-based nanosonosensitizers was fabricated with defect-rich Ti-based MOF, platinum nanoparticles and the O 2 carrier PFOB. • MOF-based nanosonosensitizers produced high levels of 1O 2 and induced ICD. • MOF-based nanosonosensitizers enhanced sono-immunotherapy against both primary tumors and metastatic tumors. Sonodynamic therapy (SDT) has emerged as a promising strategy for treating tumors owing to its non-invasiveness and high tissue-penetrating depth. Improving the efficiency of electron-hole separation of sonosensitizers and alleviation of the hypoxic tumor microenvironment remain major challenges. Metal-organic frameworks (MOFs) have greatly potential in SDT application, however, exploring new sonosensitizers with high reactive oxygen species (ROS) generation and improving the efficacy through a synergistic effect in combination with other therapeutic modalities remain major challenges. Furthermore, the immunosuppressive tumor microenvironment (TME) is characterized by hypoxia, which limit the efficacy of O 2 -dependent cancer treatments including SDT and immunotherapy. Herein, we fabricated a defect-rich titanium-based MOFs using propionic acid-mediated self-templated hierarchical etching. Reductive platinum nanoparticles were embedded onto the surface of MOFs to enhance the spatial separation of electron-hole pairs and improve the quantum yield of ultrasound-generated singlet oxygen (1O 2). Finally, perfluorobromooctane was encapsulated in the MOFs to function as an oxygen carrier to develop an oxygen self-feeding nanosensitizer. In vitro and in vivo assays demonstrated that this nanoplatform could produce high levels of 1O 2 under ultrasound irradiation, which led to enhanced SDT. Moreover, this nanoplatform also relieved the immunosuppressive TME by overcoming hypoxia and enhancing immunogenic cell death to promote the infiltration of tumor-specific cytotoxic T cells into the immunologically "cold" tumor. Therefore, combination of nanoplatform-mediated SDT with anti-PDL1 antibodies effectively inhibited the primary tumors, as well as the metastatic tumors. This study provides an insightful strategy for improving SDT and broadens the application of MOF-based sonosensitizers for sono-immunotherapy. [ABSTRACT FROM AUTHOR]

The transformation of lignocellulosic biomass to platform compounds (γ-valerolactone, GVL) was a significant component in biomass development. Herein, sulfonated Zr-based metal-organic frameworks (MOF-808), a bifunctional heterogeneous catalyst with Lewis and Bronsted acid sites, were prepared to catalyze the one-pot cascade reaction of furfural (FUR) to GVL. The successful modification of the sulfonic group on MOF-808 was substantiated by multiple characterization methods. By adjusting the sulfuric acid concentration to balance the Lewis acid and Bronsted acid sites of the catalyst, S-808–2.37 was confirmed as the preferred catalyst and a 60.4 % GVL yield was achieved with 99.1 % carbon balance under the optimal conditions. Moreover, the 72.8 % GVL yield reached in the 40x magnification experiment also boded well for the catalyst's application potential. The work in this paper opened up new perspectives for the application of MOF-808 porous materials in the field of selective catalytic conversion of biomass involving multi-step reactions. [Display omitted] • Strong interaction between Zr and OH of H 3 BDC led to the formation of strong Lewis acidic/basic sites in the frameworks. • The cooperative role of strong Lewis acidic/basic sites in the S-808–2.37 contributed to the excellent catalytic performance. • This work provided a promising strategy to modulate the acid-base properties of MOF-808 without affecting its structure. [ABSTRACT FROM AUTHOR]

Two cadmium-organic frameworks were synthesized, namely, [Cd(dptz)2]·{Cd[(NH2)2CS]4}·(NO3)4 (1, dptz=3,6-di-(pyridin-4-yl)-1,2,4,5-tetrazine) and Cd(dpmtz)2 (2, dpmtz=3,6-di-(pyridin-4-yl)-1,2-dihydro-1-mercapto-1,2,4,5-tetrazine). Compound 1 was obtained by the self-assembly of dptz, Cd(SPh)2 and thiourea under solvothermal conditions. Compound 2 was prepared through an in situ ligand reaction in which generated a new ligand dpmtz only by changing reaction temperature. Compound 1 and 2 were characterized by single-crystal X-ray structure determination, thermogravimetric analysis and powder X-ray diffraction studies. The adsorption behavior shows that compound 2 has selective adsorption capacities of CO2 over N2. [ABSTRACT FROM AUTHOR]

Two new metal-organic frameworks {[Ni 0.5 (DTA) 0.5 (H 2 O)]‧H 2 O} n (1) and [Ni(DTA)] n (2), where H 2 DTA = 2,5-di(1H-imidazol-1-yl)terephthalic acid, were constructed from the same reaction system at 120 °C and 180 °C, respectively. Different reaction temperatures were found to trigger different assembly processes and final structures. Single-crystal X-ray analyses show that compound 1 exhibits a 2D layered structure, further forming a 3D supramolecular by hydrogen bonding, while compound 2 shows 2-fold interpenetrating 3D framework with PtS topology. Compounds 1 – 2 have been evaluated as electrode materials for supercapacitors. The results show that compound 1 exhibits better electrochemical performance than 2. It may be ascribed to 2D layered structures facilitating electron transport and sufficient interlayer spaces available for the storage. Image 1 • Two Ni-based MOFs were synthesized and structurally characterized. • Different reaction temperatures were found to trigger diverse assembly processes. • Ni-DTA-2D exhibits better superior electrochemical performance. [ABSTRACT FROM AUTHOR]