Specific Screening of Prostate Cancer Individuals Using an Enzyme-Assisted Substrate Sensing Platform Based on Hierarchical MOFs with Tunable Mesopore Size

Engineering Oxidase-Based Cascade Nanoreactors Design, Catalytic Efficiency, and Applications in Disease Monitoring

Inspired by the advantages of biological cascade catalytic systems, it has been devoted to the discovery of novel oxidase-based cascade catalytic systems for disease monitoring. However, the low stability, easy inactivation, and poor reproducibility of oxidase significantly limit their practical applications. Immobilization of the oxidase can be enabled to protect them from external mediators and improve catalytic efficiency and reproducibility. Notably, the substrate channels and spatial confinement play an essential role in the construction of immobilized cascade nanoreactors to enhance the overall activity. Moreover, nanozymes, a class of enzyme mimics, have not only enzyme-like activity but also high stability and tunable catalytic properties, which bolster the development of cascade nanoreactors. Herein, recent advances in the assembly of cascade reactors involving enzymes/nanozymes are described. The importance of substrate channeling and spatial distribution in regulating the catalytic efficiency of the nanoreactor is highlighted. Then, along with an in-depth discussion of the cascade biosensors for disease monitoring, the design and application of innovative devices based on these sensing principles are also summarized, including microfluidic systems, hydrogel-based platforms, and test paper technologies. Finally, challenges and prospects for cascade nanoreactors are briefly discussed and prospected.

Hierarchical Engineering of Single-Crystalline Mesoporous Metal-Organic Frameworks with Hollow Structures

Although the superiority of hierarchical structure has driven extensive demand for applications, establishing hierarchy in a long-range-ordered single crystal remains a formidable challenge due to the inherent competition and contradiction between single crystallinity and controllable hierarchical structure. Herein, we demonstrate a growth and dissociation kinetics cooperative strategy for synthesizing a family of hollow single-crystalline mesoporous metal-organic frameworks (meso-MOFs) with hierarchical structures. The approach employs a dual-template method, integrating both hard and soft templates. By adjusting the HCl/CH3COOH ratio, the reaction system's pH can be tuned to regulate the dissociation kinetics of the acid-sensitive seeds serving as hard templates for the formation of hollow structure, while simultaneously modifying the concentration of the dual acids to control the growth kinetics of meso-MOF shells. The competition between maintaining a single crystallinity and achieving a well-defined hierarchical structure can be effectively balanced. Driven by the two interfacial kinetics, we successfully obtained the octahedral meso-MOF nanoparticles that not only exhibit a well-defined hollow structure with precisely controllable hollow size (∼81-1120 nm) and tunable wall thickness (∼28.6-61.3 nm) but also retain their single-crystal integrity. Specifically, the dissociation kinetics of seeds governed the formation of hollow structures, while the growth kinetics of single-crystalline meso-MOF shells ensured uniform coverage and structural integrity. Based on this strategy, we further developed a series of novel hollow meso-MOFs with hierarchical nanostructures, including hollow open-capsule meso-MOFs, 2D hollow meso-MOFs, hollow interlayer-structured meso-MOFs, macro-meso-micro trimodal porous MOFs, and so on.

The structuring of porous reticular materials for energy applications at industrial scales

Reticular synthesis constructs crystalline architectures by linking molecular building blocks with robust bonds. This process gave rise to reticular chemistry and permanently porous solids. Such precise control over pore shape, size and surface chemistry makes reticular materials versatile for gas storage, separation, catalysis, sensing, and healthcare applications. Despite their potential, the transition from laboratory to industrial applications remains largely limited. Among various factors contributing to this translational gap, the challenges associated with their formulation through structuring and densification for industrial compatibility are significant yet underexplored areas. Here, we focus on the shaping strategies for porous reticular materials, particularly metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), to facilitate their industrial application. We explore techniques that preserve functionality and ensure durability under rigorous industrial conditions. The discussion highlights various configurations - granules, monoliths, pellets, thin films, gels, foams, and glasses - structured to maintain the materials' intrinsic microscopic properties at a macroscopic level. We examine the foundational theory and principles behind these shapes and structures, employing both in situ and post-synthetic methods. Through case studies, we demonstrate the performance of these materials in real-world settings, offering a structuring blueprint to inform the selection of techniques and shapes for diverse applications. Ultimately, we argue that advancing structuring strategies for porous reticular materials is key to closing the gap between laboratory research and industrial utilization.

Cellulose nanofibers/polyacrylic acid hydrogels integrated with a 3D printed strip: A platform for screening prostate cancer via sarcosine detection

Cellulose nanofiber/polyacrylic acid (CNF/PAA) hydrogel-based colorimetric sensor was fabricated for non-invasive screening of prostate cancer (PCa) via selective detection of sarcosine. The hydrogel was synthesized by photo-crosslinking of acrylic acid in the presence of CNF which acted as mechanical reinforcement and as color enhancer. The hydrogel exhibited a high aqueous absorption and high mechanical strength. A homogeneous distribution of CNF in the hydrogel was confirmed by TEM. A significant improvement in the compressive modulus and stress in the hydrogel were obtained after the incorporation of 0.25%wt CNF. The hydrogel sensor was integrated within a 3D printing strip on a diaper, and it offered a vivid color change from light yellow to blue for detecting sarcosine for PCa indication with a detection limit starting from 10 μM. The colorimetric results were semi-quantitatively evaluated by a spectrophotometer offering a linear range of 0-100 μM with R2 of 0.9901. Furthermore, the increase in CNF content significantly enhanced the sensor's sensitivity toward sarcosine. This sensor could open new avenues for non-invasive screening of prostate cancer in the future.

Bifunctional mesoporous HMUiO-66-NH2 nanoparticles for bone remodeling and ROS scavenging in periodontitis therapy

Periodontal bone defects represent an irreversible consequence of periodontitis associated with reactive oxygen species (ROS). However, indiscriminate removal of ROS proves to be counterproductive for tissue repair and insufficient for addressing existing bone defects. In the treatment of periodontitis, it is crucial to rationally alleviate local ROS while simultaneously promoting bone regeneration. In this study, Zr-based large-pore hierarchical mesoporous metal-organic framework (MOF) nanoparticles (NPs) HMUiO-66-NH2 were successfully proposed as bifunctional nanomaterials for bone regeneration and ROS scavenging in periodontitis therapy. HMUiO-66-NH2 NPs demonstrated outstanding biocompatibility both in vitro and in vivo. Significantly, these NPs enhanced the osteogenic differentiation of bone mesenchymal stem cells (BMSCs) under normal and high ROS conditions, upregulating osteogenic gene expression and mitigating oxidative stress. Furthermore, in vivo imaging revealed a gradual degradation of HMUiO-66-NH2 NPs in periodontal tissues. Local injection of HMUiO-66-NH2 effectively reduced bone defects and ROS levels in periodontitis-induced C57BL/6 mice. RNA sequencing highlighted that differentially expressed genes (DEGs) are predominantly involved in bone tissue development, with notable upregulation in Wnt and TGF-β signaling pathways. In conclusion, HMUiO-66-NH2 exhibits dual functionality in alleviating oxidative stress and promoting bone repair, positioning it as an effective strategy against bone resorption in oxidative stress-related periodontitis.

Intra-Mesopore Immunoassay Based on Core-Shell Structured Magnetic Hierarchically Porous ZIFs

It is crucial yet challenging to sensitively quantify low-abundance biomarkers in blood for early screening and diagnosis of various diseases. Herein, an analytical model of intra-mesopore immunoassay (IMIA) was proposed, which was competent to examine various biomarkers at the femtomolar level. The success is rooted in the design of an innovative superparamagnetic core-shell structure with Fe3O4 nanoparticles (NPs) at the core and hierarchically porous zeolitic imidazolate frameworks as a shell (Fe3O4@HPZIF-8), achieved through a soft-template directed self-assembly coupled with confinement growth mechanism. Such a unique configuration conceptualized IMIA where the HPZIF-8 shell served as a solid carrier to cover capture antibodies while the Fe3O4 core assisted its rapid separation. The large pore channels not only provided a stable microenvironment to maintain the recognition ability of captured antibodies but also enhanced their coating density, thus promoting the probability of capturing and binding target antigens, significantly improving immunoassay (IA) sensitivity. The practical clinic IA for cTnI (Cardiac Troponin I, biomarker of acute myocardial infarction (AMI)) in human serums was exemplified. The developed IMIA could accurately quantify slight fluctuations in cTnI concentrations in the serums of AMI patients at different stages after symptom onset with more than 100-fold enhancement of limit of detection (LOD) in comparison to conventional plate-based enzyme-linked immunosorbent assay (ELISA). Such high sensitivity of IMIA makes it a powerful tool for the accurate diagnosis of different diseases by altering the type of primary capture antibody.

Uniform single-crystal mesoporous metal-organic frameworks

The synthesis of mesoporous metal-organic frameworks (meso-MOFs) is desirable as these materials can be used in various applications. However, owing to the imbalance in structural tension at the micro-scale (MOF crystallization) and the meso-scales (assembly of micelles with MOF subunits), the formation of single-crystal meso-MOFs is challenging. Here we report the preparation of uniform single-crystal meso-MOF nanoparticles with ordered mesopore channels in microporous frameworks with definite arrangements, through a cooperative assembly method co-mediated by strong and weak acids. These nanoparticles feature a truncated octahedron shape with variable size and well-defined two-dimensional hexagonally structured (p6mm) columnar mesopores. Notably, the match between the crystallization kinetics of MOFs and the assembly kinetics of micelles is critical for forming the single-crystal meso-MOFs. On the basis of this strategy, we have constructed a library of meso-MOFs with tunable large pore sizes, controllable mesophases, various morphologies and multivariate components.

Climate friendly MOFs synthesis for drug delivery systems by integrating AI, intelligent manufacturing, and quantum solutions in industry 6.0 sustainable approach

Since the Industrial Revolution, ecological damage, ecosystem disruption, and climate change acceleration have frequently resulted from human advancement at the price of the environment. Due to the rise in illnesses, Industry 6.0 calls for a renewed dedication to sustainability with latest technologies. Focused research and creative solutions are needed to achieve the UN Sustainable Development Goals (SDGs), especially 3, 9, 13, 14, 15, 17. A promising sustainable technology for enhancing healthcare while reducing environmental effect is Metal Organic Frameworks (MOFs). MOFs are perfect for drug administration because of their high surface areas, adjustable pore sizes, and remarkable drug-loading capacities. They are created by combining advanced artificial intelligence, intelligent manufacturing, and quantum computing. Researchers can create MOFs with functional groups or ligands that bind selectively to target cells or tissues, minimizing off-target effects, thanks to the distinct benefits that families like MIL, HKUST, UiO, and ZIF etc. offer for targeted drug delivery. Combining MOFs with other nanomaterials results in multipurpose systems that can handle challenging biomedical issues. Despite its promise, there are still issues with MOFs' possible toxicity and long-term stability in physiological settings. To advance their medicinal applications, these problems must be resolved. Researchers can increase the usefulness of MOFs in medicine by critically analysing these limitations and putting up creative alternatives. The creation of MOFs especially with advanced technologies (additive manufacturing etc.) for drug delivery is a prime example of how scientific advancement and environmental stewardship may coexist to provide healthcare solutions that are advantageous to both people and the environment.

Construction of Compartmentalized Meso/Micro Spaces in Hierarchically Porous MOFs with Long-Chain Functional Ligands Inspired by Biological Signal Amplification

The creation of spatially coupled meso-/microenvironments with biomimetic compartmentalized functionalities is of great significance to achieve efficient signal transduction and amplification. Herein, using a soft-template strategy, UiO-67-type hierarchically mesoporous metal-organic frameworks (HMMOFs) were constructed to satisfy the requirements of such an artificial system. The key to the successful synthesis of HMUiO-67 is rooted in the utilization of the preformed cerium-oxo clusters as metal precursors, aligning the growth of MOF crystals with the mild conditions required for the self-assembly of the soft template. The adoption of long-chain functional 2,2'-bipyridine-5,5'-dicarboxylic acid ligands not only resulted in larger microporous sizes, facilitating the transport of various cascade reaction intermediates, but also provided anchorages for the introduction of enzyme-mimicking active sites. A cascade amplification system was designed based on the developed HMUiO-67, in which enzyme cascade reactions were initiated and relayed by a target analyte in the separate but coupled meso/micro spaces. As a proof of concept, natural acetylcholinesterase (AChE) and Cu-based laccase mimetics were integrated into HMMOFs, establishing a spatially coupled nanoreactor. The activity of AChE was triggered by the target analyte of carbaryl, while the amplified products of AChE catalysis mediated the activity of biomimetic enzyme in the closely proximate microporous spaces, producing further amplification of detectable signal. This enabled the entire cascade system to respond to minimal carbaryl with a limit of detection as low as approximately 2 nM. Such a model of cascade amplification is expected to set a conceptual guideline for the rational design of various bioreactors, serving as a sensitive response system for quantifying numerous target analytes.

Intelligent Screening of Prostate Cancer Individuals Using an Enzyme-Assisted Multicolor Visualization Platform

Rapid and intelligent identification of prostate cancer (PCa) is critical for early diagnosis. Herein, a convenient, reliable, and intelligent strategy is proposed to screen PCa individuals through indirectly quantifying sarcosine (Sar), an early indicator of PCa, in clinical urine samples. Success is achieved by integrating sarcosine oxidase (SOX) as a specific recognition unit; nanozyme-assisted multicolor intelligent visualization platform as a signal reporter. With the Fe-MOFs and peroxidase, the synergetic action of SOX and response gold nanorods (Au NRs) is controlled etched to exhibit a multicolored signal. The sensor exhibits excellent linearity with Sar within 1-60 × 10-6 m, boasting a remarkable detection limit of 0.12 × 10-6 m. The RGB value of the display color can be directly extracted using a mobile phone camera. PCa diagnosis can be swiftly made (within 15 min) and directly by identifying two RGB colors (R < 175 or B > 135). The enzyme-assisted multicolor intelligent visualization platform is adept at detecting minute differences in Sar concentration in urine samples between PCa patients and healthy individuals. The concept of enzyme-assisted multicolor sensing can be further expanded by modifying the type of immobilized enzymes, providing a valuable guideline for the rational design of multiple probes to measure specific biomarkers in biological samples.

Reticular Chemistry for Enhancing Bioentity Stability and Functional Performance

Addressing the fragility of bioentities that results in instability and compromised performance during storage and applications, reticular chemistry, specifically through metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), offers versatile platforms for stabilization and enhancement of bioentities. These highly porous frameworks facilitate efficient loading and mass transfer, offer confined environments and selective permeability for stabilization and protection, and enable finely tunable biointerfacial interactions and microenvironments for function optimization, significantly broadening the applications of various bioentities, including enzymes, nucleic acids, cells, etc. This Perspective outlines strategies for integrating bioentities with reticular frameworks, highlighting new design ideas for existing issues within these strategies. It emphasizes the crucial roles of these frameworks for bioentities in enhancing stability, boosting activity, imparting non-native functions, and synergizing bioentity systems. Concluding with a discussion of the challenges and prospects in the design, characterization, and practical applications of these biocomposites, this Perspective aims to inspire further development of high-performance biocomposites in this promising field.

Biphasic interface templated synthesis of wrinkled MOFs for the construction of cascade sensing platform based on the encapsulated gold nanoclusters and enzymes

The design and construction of MOFs with flower-like structure could afford sufficient space for the immobilization of guests with large size and interconnected transport channels for their mass diffusion although it remains a challenge. Herein, wrinkled Ce-based hierarchically porous UiO-66 (Ce-WUiO-66) with good crystallinity was successfully synthesized for the first time using bicontinuous emulsion composed of 1-heptanol, water and F127 (PEO106PPO70PEO106) surfactant as a template. F127 played a key role in the formation of emulsions as a stabilizer, and meanwhile its PEO segments interacted with MOF precursors to guide the evolvement of crystallized pore walls. Through controlling the ratios of heptanol to water and the salinity, the distances of the pleat openings and the morphology of the resultant Ce-WUiO-66 were facilely regulated. In virtue of its highly open radial structure, Ce-WUiO-66 could serve as an ideal platform for loading multiple substances to build a cascade sensing system. As a proof of concept, we designed an amino acid (AA) cascade probe by co-immobilizing gold nanoclusters (AuNCs) and LAA oxidase into Ce-WUiO-66. The aggregation-induced-emission enhancement resulted from the encapsulation of AuNCs into Ce-WUiO-66 significantly improved the detection sensitivity and the detection limit of corresponding substrates reached as low as 10-8 M. The proposed biphasic interface assembly strategy is hopefully to provide a new route for the rational design of MOFs with various open pore structure and broaden their potential applications with multiple large-size substances involved besides the currently exemplified cascade sensing platform.

Leap-Type Response of Redox/Photo-Active Lanthanide-Based Metal-Organic Frameworks for Early and Accurate Screening of Prostate Cancer

The development of high-accuracy technologies to distinguish the quite tiny concentration change of tumor markers between negative and positive is of vital significance for early screening and diagnosis of cancers, but is still a great challenge for the conventional biosensors because of their "gradual" detection mode. Herein, a unique "leap-type" responsive lanthanide MOF-based biosensor (designated as Tb-CeMOF-X) with defect-mediated redox-/photo-activities is developed for precisely identifying acid phosphatase (ACP), an early pathological marker of prostate cancer (PCa) in serum. The engineered Tb-CeMOF-X probe achieves a bursting switch-on luminescence at the critical concentration of ACP (9 U ⋅ L-1), while keeping silent below this threshold, undergoing a qualitative signal change from "zero" to "one" between negative and positive indicators and thus significantly improving the identification precision. Significantly, such "leap-type" response performance can be further edited and amplified by rational defect engineering in the crystal structure to improve the accessibility of active centers, consequently maximizing the detection sensitivity toward ACP in the complex biological media. This study proposes the first paradigm for the development of "leap-type" biosensors with ultra-sensitive differentiation capability between negative and positive, and provides a potentially valuable tool for early and accurate screening of PCa.

Enzymatic cascade reactors on carbon nanotube transistor detecting trace prostate cancer biomarker

Biosensors based on carbon nanotube field-effect transistors (CNT-FETs) have shown great potential in biomarker detection due to their high sensitivity because of appreciable semiconducting electrical properties. However, background signal interferences in complex mediums may results in low signal-to-noise ratio, which may impose challenges for precise biomarker detection in physiological fluids. In this work, we develop an enzymatic CNT-FET, with scalable production at wafer scale, for detection of trace sarcosine that is a biopsy-correlated biomarker of prostate cancer. Enzymatic cascade rectors are constructed on the CNT to improve the reaction efficiency, thereby, enhancing the signal transduction. As such, a limit of detection as low as 105 zM is achieved in buffer solution. Owing to the enhanced reaction efficiency, the testing of clinical serum samples yields significant signal difference to discriminate the prostate cancer (PCa) samples from the benign prostatic hyperplasia (BPH) samples (P = 1.07 × 10-5), demonstrating immense potential in practical applications.

High-Efficiency Enzyme Assay and Screening of Enzyme-Inhibiting Nanomaterials Using Capillary Electrophoresis with Hierarchically Porous Metal-Organic Framework-Based Immobilized Enzyme Microreactor

Enzyme-inhibiting nanomaterials have significant potential for regulating enzyme activity. However, a universal and efficient method for systematically screening and evaluating the inhibitory effects of various nanomaterials on drug target enzymes has not been established. While the integrated technique of immobilized enzyme microreactor (IMER) with capillary electrophoresis (CE) serves as an effective tool for enzyme analysis, it still faces challenges such as low enzyme loadability, unsatisfactory stability, and limited applicability. Herein, hierarchical porous metal-organic frameworks (HP-MOFs) were explored as high-performance enzyme immobilization carriers and stationary phases to develop a novel HP-MOFs-based IMER-CE microanalysis system for efficient online enzyme assay and systematic screening of enzyme-inhibiting nanomaterials. As a proof-of-concept demonstration, the model enzyme xanthine oxidase (XOD) was immobilized on a HP-UiO-66-NH2 coated capillary, serving as an efficient and durable IMER for screening potential XOD-inhibiting nanomaterials. The hierarchically micro- and mesoporous structure and superior enzyme loadability of as-prepared HP-UiO-66-NH2-IMER was intensively characterized, followed by systematic evaluation of the separation performance of HP-UiO-66-NH2 coated column and the enzyme kinetics of the immobilized XOD. Compared to the microporous UiO-66-NH2-IMER, the HP-UiO-66-NH2-IMER-CE system showed significant improvements in enzyme loading, maximum reaction rate, repeatability, and long-term stability. Furthermore, the established method was effectively employed to screen the XOD inhibitory activity of various nanomaterials, revealing that graphene oxide, single wall carbon nanotube and three other nanomaterials exhibited inhibitory potentials. The HP-MOFs-based microanalysis system can be easily expanded by modifying the types of immobilized enzymes and holds the potential to accelerate the identification and rational design of effective enzyme-inhibiting nanomaterials.

Nanoengineering Multilength-Scale Porous Hierarchy in Mesoporous Metal-Organic Framework Single Crystals

Developing a reliable method for constructing mesoporous metal-organic frameworks (MOFs) with single-crystalline forms remains a challenging task despite numerous efforts. This study presents a solvent-mediated assembly method for fabricating zeolitic imidazolate framework (ZIF) single-crystal nanoparticles with a well-defined micro-mesoporous structure using polystyrene-block-poly(ethylene oxide) diblock copolymer micelles as a soft-template. The precise control of particle sizes, ranging from 85 to 1200 nm, is achieved by regulating nucleation and crystal growth rates while maintaining consistent pore diameters in mesoporous nanoparticles and a rhombohedral dodecahedron morphology. Furthermore, this study presents a robust platform for nanoarchitecturing to prepare hierarchically porous materials (e.g., core-shell and hollow structures), including microporous ZIF@mesoporous ZIF, hollow mesoporous ZIF, and mesoporous ZIF@mesoporous ZIF. Such a multimodal pore design, ranging from microporous to microporous/mesoporous and further micro-/meso-/macroporous, provides significant evidence for the future possibility of the structural design of MOFs.

Natural Protein Photon Upconversion Supramolecular Assemblies for Background-Free Biosensing

The diagnosis of disease biomarkers is crucial for the identification, monitoring, and prognostic assessment of malignant disease. However, biological samples with autofluorescence, complex components, and heterogeneity pose major challenges to reliable biosensing. Here, we report the self-assembly of natural proteins and the triplet-triplet annihilation upconversion (TTA-UC) pair to form upconverted protein clusters (∼8.2 ± 1.1 nm), which were further assembled into photon upconversion supramolecular assemblies (PUSA). This PUSA exhibited unique features, including a small size (∼44.1 ± 4.1 nm), oxygen tolerance, superior biocompatibility, and easy storage via lyophilization, all of which are long sought after for photon upconversion materials. Further, we have revealed that the steric hindrance of the annihilator suppresses the stacking of the annihilator in PUSA, which is vital for maintaining the water dispersibility and enhancing the upconversion performance of PUSA. In conjunction with sarcosine oxidase, this near infrared (NIR)-excitable PUSA nanoprobe could perform background-free biosensing of urinary sarcosine, which is a common biomarker for prostatic carcinoma (PCa). More importantly, this nanoprobe not only allows for qualitative identification of urinary samples from PCa patients by the unaided eye under NIR-light-emitting diode (LED) illumination but also quantifies the concentration of urinary sarcosine. These remarkable findings have propelled photon upconversion materials to a new evolutionary stage and expedited the progress of upconversion biosensing in clinical diagnostics.

By Introducing Multiple Hydrogen Bonds Endows MOF Electrodes with an Enhanced Structural Stability

Recently, metal-organic frameworks (MOFs) have attracted great interest in energy storage areas. However, the poor structural stability of MOFs derived from weak coordination bonds limits their applications. Here, quadruple hydrogen bonds (H-bonds) were introduced onto the MOFs to enhance their structural stability. Cross-linked networks could be formed between molecules owing to multiple H-bonds, strengthening the framework stability. Moreover, the dynamic reversibility of H-bonds could endow MOFs with self-healing ability. Furthermore, due to lower binding energy compared to coordination bonds, H-bonds break preferentially when subjected to internal stress, thus protecting the MOFs. Consequently, the as-prepared self-healing hybrid (SHH-Cu-MOF@Ti3C2TX) exhibited high capacitance retention (89.4%) after 5000 cycles at 1 A g-1, while that hybrid without dynamic H-bonds (H-Cu-MOF@Ti3C2TX) presented a 79.9% retention, delivering an enhancement in cycling stability. Moreover, an asymmetric supercapacitor (ASC) was fabricated by employing SHH-Cu-MOF@Ti3C2TX and activated carbon (AC) as the electrodes. The ASC delivered a specific capacitance (47.4 F g-1 at 1 A g-1), an energy density (16.9 Wh kg-1), and a power density (800 W kg-1) as well as good rate ability (retains 81% of its initial capacitance from 0.2 A g-1 to 5 A g-1).

Recent Advances on the Metal-Organic Frameworks-Based Biosensing Methods for Cancer Biomarkers Detection

Sensitive and selective detection of cancer biomarkers is crucial for early diagnosis and treatment of cancer, one of the most dangerous diseases in the world. Metal-organic frameworks (MOFs), a class of hybrid porous materials fabricated through the assembly of metal ions/clusters and organic ligands, have attracted increasing attention in the sensing of cancer biomarkers, due to the advantages of adjustable size, high porosity, large surface area and ease of modification. MOFs have been utilized to not only fabricate active sensing interfaces but also arouse a variety of measurable signals. Several representative analytical technologies have been applied in MOF-based biosensing strategies to ensure high detection sensitivity toward cancer biomarkers, such as fluorescence, electrochemistry, electrochemiluminescence, photochemistry and colorimetric methods. In this review, we summarized recent advances on MOFs-based biosensing strategies for the detection of cancer biomarkers in recent three years based on the categories of metal nodes, and aimed to provide valuable references for the development of innovative biosensing platform for the purpose of clinical diagnosis.

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.

Mesoporous MOFs with ROS scavenging capacity for the alleviation of inflammation through inhibiting stimulator of interferon genes to promote diabetic wound healing

Excessive production of reactive oxygen species (ROS) and inflammation are the key problems that impede diabetic wound healing. In particular, dressings with ROS scavenging capacity play a crucial role in the process of chronic wound healing. Herein, Zr-based large-pore mesoporous metal-organic frameworks (mesoMOFs) were successfully developed for the construction of spatially organized cascade bioreactors. Natural superoxide dismutase (SOD) and an artificial enzyme were spatially organized in these hierarchical mesoMOFs, forming a cascade antioxidant defense system, and presenting efficient intracellular and extracellular ROS scavenging performance. In vivo experiments demonstrated that the SOD@HMUiO-MnTCPP nanoparticles (S@M@H NPs) significantly accelerated diabetic wound healing. Transcriptomic and western blot results further indicated that the nanocomposite could inhibit fibroblast senescence and ferroptosis as well as the stimulator of interferon genes (STING) signaling pathway activation in macrophages mediated by mitochondrial oxidative stress through ROS elimination. Thus, the biomimetic multi-enzyme cascade catalytic system with spatial ordering demonstrated a high potential for diabetic wound healing, where senescence, ferroptosis, and STING signaling pathways may be potential targets.

Constructing ordered and tunable extrinsic porosity in covalent organic frameworks via water-mediated soft-template strategy

As one of the most attractive methods for the synthesis of ordered hierarchically porous crystalline materials, the soft-template method has not appeared in covalent organic frameworks (COFs) due to the incompatibility of surfactant self-assembly and guided crystallization process of COF precursors in the organic phase. Herein, we connect the soft templates to the COF backbone through ionic bonds, avoiding their crystallization incompatibilities, thus introducing an additional ordered arrangement of soft templates into the anionic microporous COFs. The ion exchange method is used to remove the templates while maintaining the high crystallinity of COFs, resulting in the construction of COFs with ordered hierarchically micropores/mesopores, herein named OHMMCOFs (OHMMCOF-1 and OHMMCOF-2). OHMMCOFs exhibit significantly enhanced functional group accessibility and faster mass transfer rate. The extrinsic porosity can be adjusted by changing the template length, concentration, and ratio. Cationic guanidine-based COFs (OHMMCOF-3) are also constructed using the same method, which verifies the scalability of the soft-template strategy. This work provides a path for constructing ordered and tunable extrinsic porosity in COFs with greatly improved mass transfer efficiency and functional group accessibility.

An intelligent ratiometric fluorescent assay based on MOF nanozyme-mediated tandem catalysis that guided by contrary logic circuit for highly sensitive sarcosine detection and smartphone-based portable sensing application

As the well-known test-indicator for early prostate cancer (PCa), sarcosine (SA) is closely related to the differential pathological process, which makes its accurate determination increasingly significant. Herein, we for the first time expanded the peroxidase (POD)-like property of facile-synthesized Zn-TCPP(Fe) MOF to fluorescent substrates and exploited it to ratiometric fluorescent (RF) sensing. By harnessing the effective catalytic oxidation of MOF nanozyme toward two fluorescent substrates (Scopoletin, SC; Amplex Red, AR) with contrary changes, and target-responsive (SA + SOx)/MOF/(SC + AR) tandem catalytic reaction, we constructed the first MOF nanozyme-based RF sensor for the quantitative determination of SA. Superior to previous works, the operation of this RF sensor is under the guidance of AND-(AND^NAND) contrary logic circuit. The dual-channel binary output changes (from 1/0 to 0/1) not only enable the intelligent logical recognition of SA, bringing strengthened reliability and accuracy, but also manifest the proof-of-concept discrimination of PCa individuals and healthy ones. Through recording the fluorescence alterations of SC (F465) and AR (F585), two segments of linear relationships between ratiometric values (F585/F465) and varied contents of SA are realized successfully. The LOD for SA could reach to as low as 39.98 nM, which outperforms all nanozyme-originated SA sensors reported till now. Moreover, this sensor also demonstrates high selectivity and satisfactory performance in human serum samples. Furthermore, the portable sensing of SA is realized under the assistance of smartphone-based RGB analysis, demonstrating the potential of point-of-care diagnostics of PCa in the future.

Fluorescence and colorimetric dual-mode multienzyme cascade nanoplatform based on CuNCs/FeMn-ZIF-8/PCN for detection of sarcosine

It is critical to develop a highly efficient and sensitive method for detecting the biomarker sarcosine (SA) of prostate cancer due to its importance for men's health. In our work, a fluorescence (FL) and colorimetric dual-mode multienzyme cascade nanoplatform for SA detection was designed and constructed. CuNCs/FeMn-ZIF-8/PCN nanocomposites with high FL properties and peroxidase-like activity were successfully prepared by encapsulating copper nanoclusters (CuNCs) into FeMn-ZIF-8 and then loaded onto P-doped graphitic carbon nitride (PCN). Furthermore, the nanocomposites served as carriers for the immobilization of sarcosine oxidase (SOX) to construct a high-efficiency dual-mode multienzyme cascade nanoplatform CuNCs/SOX@FeMn-ZIF-8/PCN for the detection of SA. The intermediate H2O2 generated in the cascade caused the FL quenching of nanocomposites and the discoloration of 3,3',5,5'-tetramethylbenzidin. The linear ranges for SA detection in the dual-mode system were 1-100 μM (FL) and 1-200 μM (colorimetric), with detection limits of 0.34 and 0.59 μM, respectively. This nanoplatform exhibited notable repeatability, specificity, and stability, making it suitable for detecting sarcosine in real human urine samples. Therefore, this dual-mode multienzyme cascade nanoplatform would have a potential applicative prospect for detecting SA and other biomarkers in real clinical samples.

Hofmeister Effect Promoted the Introduction of Tunable Large Mesopores in MOFs at Low Temperature for Femtomolar ALP Detection

In addressing the demand for hierarchically mesoporous metal-organic frameworks (HMMOFs) with adjustable large mesopores, a method based on the synergistic effects of low-temperature microemulsions and Hofmeister ions is developed. Low temperature dramatically enhanced the solubility of hydrophobic solvent in the microemulsion core, enlarging the mesopores in HMMOFs replica. Meanwhile, Hofmeister salt-in ions continuously controlled mesopore expansion by modulating the permeability of swelling agent into the microemulsion core. The large mesopores up to 33 nm provided sufficient space for the alkaline phosphatase (ALP) enrichment, and retained the remaining channel to facilitate the free mass diffusion. Leveraging these advantages, a colorimetric sensor is successfully developed using large-mesopore HMMOFs for femtomolar ALP detection based on the enrichment and cycling amplification principles. The sensor exhibited a linear detection range of 100 to 7500 fm and a limit of detection of 42 fm, presenting over 4000 times higher sensitivity than classic para-nitrophenyl phosphate colorimetric methods. Such high sensitivity highlights the importance of adjustable mesoporous structures of HMMOFs in advanced sensing applications, and prefigures their potential for detecting large biomolecules in diagnostics and biomedical research.

Preparation of Well-Constructed and Metal-Modified Covalent Organic Framework Nanoparticles for Biosensing Design with Cascade Catalytic Capability

Uniform covalent organic framework nanoparticles (COF NPs) with a well-defined pore structure may provide a robust platform for scaffolding enzymes. Herein, bipyridine-based spherical COF NPs have been successfully prepared in this work through the Schiff base condensation reaction. Moreover, they are functionalized by metal modification and are further used for biosensor fabrication. Experimental results reveal that the metal-modified COF NPs also display impressive peroxidase-like catalytic activities, while they can load enzymes, such as glucose oxidase (GOx) and sarcosine oxidase (SOx), to develop a cascade catalysis system for design of various kinds of biosensors with very well performance. For example, the optimized GOx@Fe-COFs can achieve a sensitive detection of glucose with a low limit of detection (LOD) of 12.8 μM. Meanwhile, the enzymes also exhibit a commendable preservation of 80% enzymatic activity over a span of 14 days under ambient conditions. This work may pave the way for advancing cascade catalysis and the analysis of different kinds of biological molecules based on COF NPs.

A closed-loop catalytic nanoreactor system on a transistor

Precision chemistry demands miniaturized catalytic systems for sophisticated reactions with well-defined pathways. An ideal solution is to construct a nanoreactor system functioning as a chemistry laboratory to execute a full chemical process with molecular precision. However, existing nanoscale catalytic systems fail to in situ control reaction kinetics in a closed-loop manner, lacking the precision toward ultimate reaction efficiency. We find an inter-electrochemical gating effect when operating DNA framework-constructed enzyme cascade nanoreactors on a transistor, enabling in situ closed-loop reaction monitoring and modulation electrically. Therefore, a comprehensive system is developed, encapsulating nanoreactors, analyzers, and modulators, where the gate potential modulates enzyme activity and switches cascade reaction "ON" or "OFF." Such electric field-effect property enhances catalytic efficiency of enzyme by 343.4-fold and enables sensitive sarcosine assay for prostate cancer diagnoses, with a limit of detection five orders of magnitude lower than methodologies in clinical laboratory. By coupling with solid-state electronics, this work provides a perspective to construct intelligent nano-systems for precision chemistry.

Hofmeister Effects Shine in Nanoscience

Hofmeister effects play a crucial role in nanoscience by affecting the physicochemical and biochemical processes. Thus far, numerous wonderful applications from various aspects of nanoscience have been developed based on the mechanism of Hofmeister effects, such as hydrogel/aerogel engineering, battery design, nanosynthesis, nanomotors, ion sensors, supramolecular chemistry, colloid and interface science, nanomedicine, and transport behaviors, etc. In this review, for the first time, the progress of applying Hofmeister effects is systematically introduced and summarized in nanoscience. It is aimed to provide a comprehensive guideline for future researchers to design more useful Hofmeister effects-based nanosystems.

Enzyme‐Encapsulated Protein Trap Engineered Metal–Organic Framework‐Derived Biomineral Probes for Non‐Invasive Prostate Cancer Surveillance

A paper‐based naked‐eye recognition assay with enzyme‐encapsulated protein engineered metal–organic framework‐derived biominerals is developed for direct quantification of sarcosine in urine samples for screening of prostate cancer individuals. The detection strategy stems from the successful construction of a cascade response model, which involves the introduction of a cascade enzymatic catalytic reaction on Pt nanoparticles (NPs)‐loaded porous CeO2 by integrating a sarcosine oxidase as a special recognition unit and a chromogenic substrate as a signal molecule reporter. Pt NPs‐loaded CeO2 is subjected to a one‐step thermal treatment based on multilayered mesoporous Ce‐based metal–organic framework, and the calcined CeO2 exhibits the same distinct porous graded structure. Importantly, introduction of Pt NPs sharply enhances the peroxidase‐like activity of CeO2, which is considered to be caused by the difference in the adsorption behavior of hydrogen peroxide on the CeO2 surface and Pt/CeO2 obtained by density functional theory calculations. On the basis of this, the probe is used on a mass‐producible paper‐based working platform and 3D‐printed device to specifically screen for minor differences in sarcosine between urine samples from cancer patients and normal individuals. Enzyme‐assisted cascade catalytic reaction can be extended by replacing different recognition units for multiple analytes.

Metal-Organic Framework (MOF)-A Universal Material for Biomedicine

Metal-organic frameworks (MOFs) are a very promising platform for applications in various industries. In recent years, a variety of methods have been developed for the preparation and modification of MOFs, providing a wide range of materials for different applications in life science. Despite the wide range of different MOFs in terms of properties/sizes/chemical nature, they have not found wide application in biomedical practices at present. In this review, we look at the main methods for the preparation of MOFs that can ensure biomedical applications. In addition, we also review the available options for tuning the key parameters, such as size, morphology, and porosity, which are crucial for the use of MOFs in biomedical systems. This review also analyses possible applications for MOFs of different natures. Their high porosity allows the use of MOFs as universal carriers for different therapeutic molecules in the human body. The wide range of chemical species involved in the synthesis of MOFs makes it possible to enhance targeting and prolongation, as well as to create delivery systems that are sensitive to various factors. In addition, we also highlight how injectable, oral, and even ocular delivery systems based on MOFs can be used. The possibility of using MOFs as therapeutic agents and sensitizers in photodynamic, photothermal, and sonodynamic therapy was also reviewed. MOFs have demonstrated high selectivity in various diagnostic systems, making them promising for future applications. The present review aims to systematize the main ways of modifying MOFs, as well as the biomedical applications of various systems based on MOFs.

A DNA/DMXAA/Metal-Organic Framework Activator of Innate Immunity for Boosting Anticancer Immunity

Immunotherapy has achieved revolutionary success in clinics, but it remains challenging for treating hepatocellular carcinoma (HCC) characterized by high vascularization. Here, it is reported that metal-organic framework-801 (MOF-801) can be employed as a stimulator of interferon genes (STING) through Toll-like receptor 4 (TLR4) not just as a drug delivery carrier. Notably, cytosine-phosphate-guanine oligodeoxynucleotides (CpG ODNs) and 5, 6-dimethylxanthenone-4-acetic acid (DMXAA) STING agonist with vascular disrupting function coordinates with MOF-801 to self-assemble into a nanoparticle (MOF-CpG-DMXAA) that effectively delivers CpG ODNs and DMXAA to cells for synergistically improving the tumor microenvironment by reprogramming tumor-associated macrophages (TAMs), promoting dendritic cells (DCs) maturation, as well as destroying tumor blood vessels. In HCC-bearing mouse models, it is demonstrated that MOF-CpG-DMXAA triggers systemic immune activation and stimulates robust tumoricidal immunity, resulting in a superior immunotherapeutic efficiency in orthotopic and recurrent HCC.

Mesoporous Nanozyme-Enhanced DNA Tetrahedron Electrochemiluminescent Biosensor with Three-Dimensional Walking Nanomotor-Mediated CRISPR/Cas12a for Ultrasensitive Detection of Exosomal microRNA

Exosomal microRNAs (exomiRNAs) have emerged as ideal biomarkers for early clinical diagnostics. The accurate detection of exomiRNAs plays a crucial role in facilitating clinical applications. Herein, an ultrasensitive electrochemiluminescent (ECL) biosensor was constructed using three-dimensional (3D) walking nanomotor-mediated CRISPR/Cas12a and tetrahedral DNA nanostructures (TDNs)-modified nanoemitters (TCPP-Fe@HMUiO@Au-ABEI) for exomiR-155 detection. Initially, the 3D walking nanomotor-mediated CRISPR/Cas12a strategy could effectively convert the target exomiR-155 into amplified biological signals for improving the sensitivity and specificity. Then, TCPP-Fe@HMUiO@Au nanozymes with excellent catalytic performance were used to amplify ECL signals because of the enhanced mass transfer and increased catalytic active sites, originating from its high surface areas (601.83 m²/g), average pore size (3.46 nm), and large pore volumes (0.52 cm³/g). Meanwhile, the TDNs as the scaffold to fabricate "bottom-up" anchor bioprobes could improve the trans-cleavage efficiency of Cas12a. Consequently, this biosensor achieved the limit of detection down to 273.20 aM ranging from 1.0 fM to 1.0 nM. Furthermore, the biosensor could discriminate breast cancer patients evidently by analyzing exomiR-155, and these results conformed to that of qRT-PCR. Thus, this work provides a promising tool for early clinical diagnostics.

Circulating metabolite biomarkers: a game changer in the human prostate cancer diagnosis

PURPOSE

Prostate cancer (PCa) is the second most commonly diagnosed cancer in men in Western and Asian countries. Serum prostate-specific antigen (PSA) test has been the routine diagnostic method despite the tremendous research in diagnostic markers for early detection of PCa. A shift towards a promising and potential biomarker for PCa detection is through metabolomic profiling of biofluids, particularly the blood and urine samples. Finding reliable, routinely usable circulating metabolite biomarkers may not be a distant reality.

METHODS

We performed a PubMed-based literature search of metabolite biomarkers in blood and urine for the early detection of prostate cancer. The timeline of these searches was limited between 2007 and 2022 and the following keywords were used: 'metabolomics', 'liquid biopsy', 'circulating metabolites', 'serum metabolite', 'plasma metabolite', and 'urine metabolite' with respect to 'prostate cancer'. We focussed only on diagnosis-based studies with only the subject-relevant articles published in the English language and excluded all of the other irrelevant publications that included prostate tissue biomarkers and cell line biomarkers.

RESULTS

We have consolidated all the blood and urine-based potential metabolite candidates in individual as well as panels, including lipid classes, fatty acids, amino acids, and volatile organic compounds which may become useful for PCa diagnosis.

CONCLUSION

All these metabolome findings unveil the impact of different dimensions of PCa development, giving a promising strategy to diagnose the disease since suspected individuals can be subjected to repeated and largescale blood and urine testing.

Dual-Modal Apoptosis Assay Enabling Dynamic Visualization of ATP and Reactive Oxygen Species in Living Cells

ATP and reactive oxygen species (ROS) are considered significant indicators of cell apoptosis. However, visualizing the interplay between apoptosis-related ATP and ROS is challenging. Herein, we developed a metal-organic framework (MOF)-based nanoprobe for an apoptosis assay using duplex imaging of cellular ATP and ROS. The nanoprobe was fabricated through controlled encapsulation of gold nanorods with a thin zirconium-based MOF layer, followed by modification of the ROS-responsive molecules 2-mercaptohydroquinone and 6-carboxyfluorescein-labeled ATP aptamer. The nanoprobe enables ATP and ROS visualization via fluorescence and surface-enhanced Raman spectroscopy, respectively, avoiding the mutual interference that often occurs in single-mode methods. Moreover, the dual-modal assay effectively showed dynamic imaging of ATP and ROS in cancer cells treated with various drugs, revealing their apoptosis-related pathways and interactions that differ from those under normal conditions. This study provides a method for studying the relationship between energy metabolism and redox homeostasis in cell apoptosis processes.

Enhanced Activity of Enzyme Immobilized on Hydrophobic ZIF-8 Modified by Ni2+ Ions

The development of efficient enzyme immobilization to promote their recyclability and activity is highly desirable. Zeolitic imidazolate framework-8 (ZIF-8) has been proved to be an effective platform for enzyme immobilization due to its easy preparation and biocompatibility. However, the intrinsic hydrophobic characteristic hinders its further development in this filed. Herein, a facile synthesis approach was developed to immobilize pepsin (PEP) on the ZIF-8 carrier by using Ni²⁺ ions as anchor (ZIF-8@PEP-Ni). By contrast, the direct coating of PEP on the surface of ZIF-8 (ZIF-8@PEP) generated significant conformational changes. Electrochemical oxygen evolution reaction (OER) was employed to study the catalytic activity of immobilized PEP. The ZIF-8@PEP-Ni composite attains remarkable OER performance with an ultralow overpotential of only 127 mV at 10 mA cm^-2 , which is much lower than the 690 and 919 mV overpotential values of ZIF-8@PEP and PEP, respectively.

Tryptophan-Modulated Nanoscale Metal-Organic Framework for Coordinated Loading of Biomolecules for Cascade Production of Reactive Oxygen and Nitrogen Species

Owing to the high surface area and porosity, metal-organic frameworks (MOFs) could be utilized as both nanocarriers of biopharmaceuticals and nanoreactors to organize cascade biological reactions with great potential in cancer treatment. However, nanoscale MOFs suitable for biomedical applications rely on harsh preparation conditions. Here, we utilized tryptophan to modulate the morphology and optical properties of zeolitic imidazolate framework-8 (ZIF-8) as nanocarrier to efficiently encapsulate the enzyme and mRNA. Under room temperature in an aqueous solution, tryptophan would coordinate with zinc ions to form ZIF-8:Trp with a decreased size from the μm range to sub-200 nm. In addition, cargo release could be monitored in real time via fluorescence red-shift effects. Besides being used as nanocarriers of biomolecules, ZIF-8:Trp could also be utilized as nanoreactors to induce cascade reactions to produce reactive oxygen and nitrogen species. Overall, this nanosized ZIF-8:Trp could provide a new strategy for preparation of cascade bioreactions and provide new insight for gas therapy.

Mechanistic Principles for Engineering Hierarchical Porous Metal-Organic Frameworks

Metal-organic frameworks (MOFs) have generated tremendous research interest in the past two decades, due to their high surface areas, tailorable active sites, and tunable structures. Hierarchical porous MOFs (HP-MOFs) with two or more pore systems are particularly attractive, benefiting from improved active site accessibility and enhanced mass diffusivity in applications involving bulk molecules. This review outlines the mechanistic principles used for the rational design of HP-MOFs, current techniques used to measure their hierarchical porosities, as well as their emerging applications. We then critically summarize the current challenges in this field and provide a contemporary perspective on the technological innovations that would address current synthetic challenges in the field of HP-MOFs. The aim of this review is to provide an in-depth understanding of the formation mechanisms, materials chemistry, and structural and chemical properties of HP-MOFs while exploring ways to enhance the performance of current MOF materials in a range of fields.

Piezotronic Effect-Assisted Photoelectrochemical Exosomal MicroRNA Monitoring Based on an Electron Donor Self-Supplying Strategy

Exosomal microRNAs (miRNAs) as newly emerging reliable and noninvasive biomarkers have demonstrated a significant function in early cancer diagnosis. Photoelectrochemical (PEC) biosensing has attracted unprecedented attention in exosomal miRNA monitoring due to its inherent advantages of both electrochemical and optical techniques; however, the severe charge carrier recombination greatly restricts the PEC assay performance. Herein, a high-sensitive PEC strategy assisted by the piezoelectric effect is designed based on Bi₂WO₆/Cu₂S heterojunctions and implemented for the monitoring of exosomal miRNAs. The introduction of the piezoelectric effect enables promoted electron-hole transfer and separation, thereby improving the analytical sensitivity. In addition, a target reprogramming metal-organic framework-capped CaO₂ (MOF@CaO₂) hybrids is prepared, in which MOF@CaO₂ being responsive to exosomal miRNAs induces exposure of the capped CaO₂ to H₂O and then triggers self-supplying of H₂O₂, which effectively suppresses the electron-hole recombination, giving rise to an amplified photocurrent and a decrease in the cost of the reaction. Benefiting from the coupled sensitization strategy, the as-fabricated PEC strategy exhibits high sensitivity, specificity, low cost, and ease of use for real-time analysis of exosomal miRNAs within the effectiveness linear range of 0.1 fM-1 μM. The present work demonstrates promising external field coupling-enhanced PEC bioassay and offers innovative thoughts for applying this strategy in other fields.

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.

2D/3D-Shaped Fe0.8Ni0.2S2/ZIF-67 as a Nanozyme for Rapid Measurement of H2O2 and Ascorbic Acid with a Low Limit of Detection

Metal-organic frameworks (MOFs) can be used as ideal artificial nanozymes for an open structure to transfer substances and products. The nanozymic mechanism of MOFs needs further investigation for wide application. In this manuscript, no peroxidase-like activity was found for ZIF-67 (a kind of MOF), however, it enhanced the peroxidase-like activity of the Fe_0.8Ni_0.2S₂/ZIF-67 composite, in which Fe_0.8Ni_0.2S₂ was the active composition. The catalytic constant (K_cat) is higher at 1.98 (for TMB) and 2.08 (for H₂O₂) times and the catalytic efficiency (K_cat/K_m) is higher at 3.13 (for TMB) and 2.67 (for H₂O₂) times, than those of Fe_0.8Ni_0.2S₂. The K_m value decreased about 85 times (for H₂O₂) for Fe_0.8Ni_0.2S₂/ZIF-67 than that of horseradish peroxidase (natural enzyme). The mechanism was proposed. The limit of detection of H₂O₂ for Fe_0.8Ni_0.2S₂/ZIF-67 is 0.039 μM, which is lower by about 18.2 times than that of Fe_0.8Ni_0.2S₂. Simultaneously, Fe_0.8Ni_0.2S₂/ZIF-67 was used to rapidly detect ascorbic acid for only 1.0 min in food monitoring. This study may be important to design a new kind of nanozyme.

Hierarchical large-pore MOFs templated from poly(ethylene oxide)-b-polystyrene diblock copolymer with tuneable pore sizes

Diblock copolymer poly(ethylene oxide)-b-poly(styrene) (PEO-b-PS) was adopted to template the synthesis of hierarchically porous Ce-based metal-organic frameworks (MOFs) for the first time. By extending the synergistic effect of Hofmeister ions and soft templates into the water-rich system, UiO-66 type Ce-MOFs with a mesopore size of about 15 nm were achieved. Mesopore size could be further tuned up to approximately 23 nm upon introducing 1,3,5-trimethylbenzene to the micelle core of PEO-b-PS.

Hierarchically Porous MOFs Synthesized by Soft-Template Strategies

The past few decades have been witnessing the rapid research boom of metal-organic frameworks (MOFs), which are assembled from metal nodes and multitopic organic linkers. In virtue of their modular assembly mode, they can be tailored according to desired functions to satisfy numerous potential applications. However, most initially reported MOFs were restricted to the microporous regime, limiting their practical applications with bulk molecules involved. Therefore, the research attention was immediately directed toward enlarging the intrinsic pore size of frameworks by extending the secondary building units or organic ligands. Unfortunately, the synthesis of more extended ligands is frequently tedious, and the most resultant MOFs are not sufficiently stable, restricting their popularization. The soft-template strategy is recognized as a promising avenue to produce hierarchically porous MOFs (HPMOFs), although early attempts generally failed due to the incompatibility between the surfactant self-assembly and guided crystallization process of MOF precursors in the organic phase. Therefore, developing a rational soft-template strategy to achieve the precise control of morphology and porosity of HPMOFs is of great significance.In this Account, we present our recent progress on the development and applications of HPMOFs prepared by soft-template strategies. We highlight the key issues upon using the soft-template strategy to synthesize HPMOFs. To enhance the interaction between the template and MOF precursor, a long-chain monocarboxylic acid strategy is introduced to synthesize HPMOFs with irregular mesopores in the organic phase. Then, to improve the order of mesopores, an aqueous-phase synthesis method using amphoteric surfactants as templates is developed to prepare ordered HPMOFs. To further enlarge the pore size and make the synthesis conditions of MOFs compatible with the self-assembly of surfactants, a salting-in species-induced self-assembly strategy is proposed and coupled with the structure-directing properties of copolymer templates to synthesize a series of HPMOFs with large mesopores and even macropores. This salting-in ion-mediated self-assembly (SIMS) strategy paves the way to modify the pore size, pore structure, morphology, and chemical composition of HPMOFs. The separated but intimately interconnected hierarchical pores in the resultant HPMOFs can not only realize rapid mass transport but also isolate different-size guest molecules so that they are competent for a broad range of applications including protein digestion, cascade catalysis, enzyme-assisted substrate sensing, and DNA cleavage. Finally, the limitations, challenges, and future developments of this rapidly evolving field are described. This Account with a highlight to the soft-template strategies not only provides interesting insights to understand the assembly process between templates and MOFs but also inspires an optimization of the properties of HPMOFs from diverse aspects for desired applications.

A perylenediimide modified SiO2@TiO2 yolk-shell light-responsive nanozyme: Improved peroxidase-like activity for H2O2 and sarcosine sensing

Although light-responsive nanozyme have been widely used in colorimetric sensing, some limitations such as poor catalytic activity, low detection efficiency, and unclear structure-activity relationships remain unresolved. Herein, we prepared an excellent light-responsive peroxidase (POD) mimic, perylenediimide (PDI-OH) modified SiO₂ @TiO₂ yolk-shell spheres (SiO₂ @TiO₂/PDI-OH), based on DFT-assisted design. The experiment and DFT calculation revealed that the enhanced POD-like activity was mainly attributed to a suitable built-in electric field among adjacent PDI-OH molecules on the surface of the SiO₂ @TiO₂ and the unique yolk-shell structure with more reaction sites of SiO₂ @TiO₂. Consequently, the highly selective and ultrasensitive detection of H₂O₂ is achieved with a detection limit (LOD) of 7.6 × 10^-8M. Further, the selective detection of sarcosine with LOD of 1.2 × 10^-7 M was also achieved by introducing sarcosine oxidase (SOx). This colorimetric assay is successfully applied to selectively detect H₂O₂ and sarcosine levels in real samples. Controlled response time, anti-interference, and the robustness of the developed colorimetric sensor are the key advantages. And the present work firstly clarifies the effect of PDIs substituents on the POD-like activity of light-responsive nanozymes and provided new guidelines to develop high-performance nanozymes for hazardous substances detection.

One-Step Thermophoretic AND Gate Operation on Extracellular Vesicles Improves Diagnosis of Prostate Cancer

Circulating extracellular vesicles (EVs) have emerged as a valuable source of cancer biomarkers. However, the high degree of EV heterogeneity and the complexity of clinical samples pose a challenge in the sensitive identification of tumor-derived EVs. Here we introduce a one-step thermophoretic AND gate operation (Tango) assay that integrates polyethylene glycol (PEG)-enhanced thermophoretic accumulation of EVs and simultaneous AND gate operation on EV membranes by dual-aptamers recognition. By using the Tango assay to detect tumor-derived EVs with co-presence of EpCAM and PSMA directly from serum in a homogeneous, separation-free format, we can discriminate prostate cancer (PCa) patients from benign prostatic hyperplasia (BPH) patients in the diagnostic gray zone with an accuracy of 91 % in 15 min. Our approach streamlines EV enrichment and AND gate operation on EVs in a single assay, providing a rapid, straightforward, and powerful method for precise and non-invasive diagnosis of cancer.

A versatile biomimetic multienzyme cascade nanoplatform based on boronic acid-modified metal-organic framework for colorimetric biosensing

The combination of bio- and chemo-catalysts for sequential cascades has received considerable attention in analytical fields because of the regulable catalytic efficiency and selectivity under various physiological conditions. In this paper, a versatile multienzyme cascade nanoplatform with excellent activity for biosensing is demonstrated by combining metal-organic framework (MOF)-based nanozyme with natural enzymes. A boronic acid-modified MOF, MIL-100(Fe)-BA, was obtained via a microwave-assisted metal-ligand-fragment co-assembly strategy. On the one hand, MIL-100(Fe)-BA could serve as a nanozyme with dual oxidase/peroxidase bioactivity to detect glutathione and ascorbic acid with a detection limit of 0.12 μM and 0.09 μM, respectively. On the other hand, the hierarchically porous MIL-100(Fe)-BA possesses adequate recognition sites for immobilizing enzymes with acceptable protein leakage, enabling it to act like a scaffold for the fixation of a single enzyme (sarcosine oxidase) or bi-enzymes (acetylcholinesterase/choline oxidase) and guide a multienzyme cascade reaction system with high efficiency. The cascade nanoplatform has merits of both artificial nanozymes and natural enzymes, providing satisfactory sarcosine/acetylcholine sensing ability with detection limits of 0.26 μM and 1.18 μM. The developed catalytic system not only expands the application of nanozymes in tandem enzymatic bio-catalysis, but provides a facile and efficient multienzyme cascade nanoplatform for biosensing and other applications.

Nanoemulsion-directed growth of MOFs with versatile architectures for the heterogeneous regeneration of coenzymes

As one of the most appealing strategies for the synthesis of nanomaterials with various architectures, emulsion-directed methods have been rarely used to control the structure of metal-organic frameworks (MOFs). Herein, we report a versatile salt-assisted nanoemulsion-guided assembly to achieve continuous architecture transition of hierarchical Zr-based MOFs. The morphology of nanoemulsion can be facilely regulated by tuning the feed ratio of a dual-surfactant and the introduced amount of compatible hydrophobic compounds, which directs the assembly of MOFs with various architectures such as bowl-like mesoporous particle, dendritic nanospheres, walnut-shaped particles, crumpled nanosheets and nanodisks. The developed dendritic nanospheres with highly open and large mesochannels is successfully used as matrix for the co-immobilization of coenzymes and corresponding enzymes to realize the in situ heterogeneous regeneration of NAD⁺. This strategy is expected to pave a way for exploring sophisticated hierarchical MOFs which can be competent for practical applications with bulk molecules involved.

Controlling the structure of hierarchical metal-organic frameworks via soft template remains a challenge. Here, the authors report a salt-assisted nanoemulsion-guided strategy to achieve continuous structure transition of hierarchical Zr-based MOFs.

Biomimic Nanozymes with Tunable Peroxidase-like Activity Based on the Confinement Effect of Metal-Organic Frameworks (MOFs) for Biosensing

Biomimic nanozymes coassembled by peptides or proteins and small active molecules provide an effective strategy to design attractive nanozymes. Although some promising nanozymes have been reported, rational regulation for higher catalytic activity of biomimic nanozymes remains challenging. Hence, we proposed a novel biomimic nanozyme by encapsulating the coassembly of hemin/bovine serum albumin (BSA) in zeolite imidazolate frameworks (ZIF-8) to achieve controllable tailoring of peroxidase-like activity via the confinement effect. The assembly of Hemin@BSA was inspired by the structure of horseradish peroxidase (HRP), in which hemin served as the active cofactor surrounded by BSA as a blocking pocket to construct a favorable hydrophobic space for substrate enrichment. Benefiting from the confinement effect, ZIF-8 with a porous intracavity was identified as the ideal outer layer for Hemin@BSA to accelerate substrate transport and achieve internal circulation of peroxidase-like catalysis, significantly enhancing its peroxidase-like activity. Especially, the precise encapsulation of Hemin@BSA in ZIF-8 could also prevent it from decomposition in harsh environments by rapid crystallization around Hemin@BSA to form a protective shell. Based on the improved peroxidase-like activity of Hemin@BSA@ZIF-8, several applications were successfully performed for the sensitive detection of small molecules including H₂O₂, glucose, and bisphenol A (BPA). Satisfactory results highlight that using a ZIF-8 outer layer to encapsulate Hemin@BSA offers a very effective and successful strategy to improve the peroxidase-like activity and the stability of biomimic nanozymes, broadening the potential application of biocatalytic metal-organic frameworks (MOFs).