Porphyrin-based Metal-organic Frameworks Research Articles

Solvent-mediated synthesis of 2D In-TCPP MOF nanosheets for enhanced photodynamic antibacterial therapy

Two-dimensional (2D) metal-organic frameworks (MOFs) have emerged as promising photosensitizers in photodynamic therapy in recent years. In comparison to bulk MOFs, constructing 2D MOFs can increase the presence of active sites through increasing the surface area ratio. Herein, we report a simple solvent-mediated synthesis method for preparation of 2D porphyrin-based MOF (In-TCPP) nanosheets without the addition of any surfactants as an efficient photosensitizer for enhancing photodynamic antibacterial therapy. The accurate regulation of the morphology and size of 2D In-TCPP nanosheets can be achieved by varying the ratio of water to N,N-dimethylformamide solvent with the appropriate assistance of pyridine. The optimal synthesized 2D In-TCPP nanosheets exhibit a diameter of 70-120 nm and a thickness of 21.5-27.4 nm. Promisingly, 2D In-TCPP nanosheets produce a higher amount of 1O2 when exposed to 660 nm laser compared to the In-TCPP bulk, indicating that the smaller nanosheets possess more active sites for reactive oxygen species generation and can greatly improve the antibacterial photodynamic therapeutic effect. Both the in vitro and in vivo results prove that the In-TCPP nanosheets can be used as a photosensitizer for efficient photodynamic antibacterial therapy to kill S. aureus and promote wound healing.

Boosting photothermal conversion through array aggregation of metalloporphyrins in bismuth-based coordination frameworks.

Materials capable of efficiently converting near-infrared (NIR) light into heat are highly sought after in biotechnology. In this study, two new three-dimensional (3D) porphyrin-based metal-organic frameworks (MOFs) with a sra-net, viz. CoTCPP-Bi/NiTCPP-Bi, were successfully synthesized. These MOFs feature bismuth carboxylate nodes interconnected by metalloporphyrinic spacers, forming one-dimensional (1D) arrays of closely spaced metalloporphyrins. Notably, the CoTCPP-Bi exhibits an approximate Co⋯C distance of 3 Å, leading to enhanced absorption of NIR light up to 1400 nm due to the presence of strong interlayer van der Waals forces. Furthermore, the spatial arrangement of the metalloporphyrins prevents axial coordination at the centers of porphyrin rings and stabilizes a CoII-based metalloradical. These characteristics promote NIR light absorption and non-radiative decay, thereby improving photothermal conversion efficiency. Consequently, CoTCPP-Bi can rapidly elevate the temperature from room temperature to 190 °C within 30 seconds under 0.7 W cm-2 energy power from 808 nm laser irradiation. Moreover, it enables solar-driven water evaporation with an efficiency of 98.5% and a rate of 1.43 kg m-2 h-1 under 1 sun irradiation. This research provides valuable insights into the strategic design of efficient photothermal materials for effective NIR light absorption, leveraging the principles of aggregation effect and metalloradical chemistry.

Porphyrin-based-MOF nanocomposite hydrogels for synergistic sonodynamic and gas therapy against tumor

The glioma is one of the most aggressive tumors in humans, which is difficult to eradicate clinically. Therefore, we devised a porphyrin-based metal-organic frameworks (MOFs) crosslinking hyaluronic acid (HA) hydrogel nanocomposite through double-network (Cu-MOF-S-S-HA-Gel, CSSH-Gel), which is tumor responsive for enhanced gas therapy and sonodynamic therapy (SDT). Firstly, the hydrogels show extraordinary injectability and biocompatibility, which enables intratumor administration to circumvent the danger associated with surgery. The Cu-MOF-Cys and HA-Cys are interconnected through ether and disulfide bonds to establish a dual-network gel structure. The overexpressed glutathione (GSH) in tumor microenvironment (TME) reacts with disulfide bonds to release of the nanosensitizer (Cu-MOF). Subsequently, Cu-MOF generates reactive oxygen species (ROS) upon ultrasound irradiation for SDT, and releases L-cysteine(L-Cys) catalyzed by 3-mercapto pyruvate sulfotransferase (3-MST) to generate H2S for gas therapy. The CSSH-Gel obtained excellent synergistic anti-tumor effects (82.34 % inhibition ratio in vivo), which holds tremendous promise for the advancement of minimally invasive glioma therapies.

A cathodic photoelectrochemical self-powered aptasensor for ratiometric detection of cortisol based on PCN-224@graphene nanocomposites

Cathodic photoelectrochemical (PEC) sensors have garnered considerable research interest in bioanalysis for their ability to mitigate interference from photogenerated holes in concomitant reducing substances, but there remains a challenge to improve detection accuracy with rational strategies. In this study, a ratiometric assay was developed for cathodic PEC aptasensing of cortisol (COR), a stress hormone. Under visible-light exposure, porphyrin-based metal organic framework (PCN-224) and poly(diallyldimethylammonium chloride)-modified reduced graphene oxide (PrGO) composites were utilized as photoactive materials, enabling cathodic photocurrent production at 0 V. The spatially resolved dual photocathodes were combined with a COR-binding aptamer to selectively recognize the COR target, with one serving as the control. The ratio of the concentration-dependent inhibited photocurrent response (PI1) to the reference signal (PI2) from the control photocathode was employed for the sensitive COR bioassay. The proposed aptasensor revealed a broad linear range toward COR concentration from 0.4 nM to 800 nM, with a detection limit (3S/N) of 0.14 nM. The proposed sensor was successfully applied to real human serum samples, demonstrating promise in detecting disease markers in medical diagnostics.

Highly efficient electrochemiluminescent properties of porphyrin-based metal-organic framework Zn-TCPP and its immunoassay application to the detection of ochratoxin A

BackgroundOchratoxin A (OTA) is a group of mycotoxins that are widely distributed in food and feed and are closely associated with human health, so it is particularly important to detect OTA in cereal-based foods. Porphyrins and their derivatives have been widely investigated for their excellent electrochemical luminescence properties. Tetrakis 4-carboxyphenyl) porphyrin (TCPP) has limited applications because of its tendency to aggregate in water. ResultsTo enhance the luminescence efficiency of TCPP, the porphyrin can be immobilized as an organic ligand in a metal-organic framework. This allows the preparation of a novel zinc-porphyrin-based MOF (Zn-TCPP nanorods), which in turn provides highly efficient and stable cathodic ECL signals. Herein, an ultra-sensitive electrochemiluminescence immunoassay was proposed using Zn-TCPP nanorods as high-efficiency luminophores and Bi2S3@Au nanoflowers as electrode substrate materials for the detection of ochratoxin A in foodstuffs. Zn-TCPP has a strong and stable signal, and has been used as an immunosensor probe material. The Bi2S3@Au nanoflowers was used to decorate the glass carbon electrode and support for antibody immobilization due to its good electrical conductivity and large specific surface area. Under the optimized conditions, the constructed immunosensor could realize the sensitive detection of ochratoxin A in the detection range of 0.0004 ng mL−1 to 500 ng mL−1 with the detection limit as low as 0.13 pg mL−1. In addition, the sensing platform has been used for the detection of OTA in wheat flour and feed. SignificanceHence, it is worth believing that this strategy can pave a bright research direction for the detection of ochratoxin A or other small molecule mycotoxins content in foods, as well as contributing to the further study of MOF in the field of ECL.

Enhanced bacterial disinfection of multi-drug resistance bacteria by PCN@AgI heterojunction under visible light irradiation

Pathogenic bacterial infections have become a continuing threat to human health over the past decade, the development of novel antibacterial agents or strategies against drug-resistance bacteria is highly desirable. Although porphyrin-based metal organic frameworks (PCN) are important photosensitizers (PSs) for photodynamic antibacterial treatments, they are inefficient for killing gram-negative bacteria such as Escherichia coli. Herein, PCN@AgI heterojunction was prepared as a novel and potent multifunctional antibacterial agent to combat bacteria including drug-resistance bacteria such as extended-spectrum β-lactamaseEscherichia coli (ESBL) under visible light irradiation in vitro, attributing to the cooperation of the generated ROS and released Ag+ as well as GSH-depleting ability. Compared to pristine PCN, the formation of heterojunction between AgI and PCN facilitated the sufficient separation of the produced electron- hole pairs, leading to enhanced photocatalytic antibacterial capability by producing sufficient ROS. Furthermore, its GSH-depleting ability due to its oxidase-like behavior further boosted its antibacterial capability. Significantly, in vivo studies demonstrated that PCN@AgI heterojunction could promote the healing of E. coli-infected wound on rice back with high biosafety. These findings manifested that PCN@AgI heterojunction was a good potential antibacterial therapeutic agent and may hold promise in bacteria-infected wound healing.

Nonequilibrium bandgap modification in porphyrin-based metal-organic frameworks revealed by transient absorption spectroscopy

Modifying the equilibrium bandgap has proven to be an effective strategy for optimizing photocarrier properties in metal-organic frameworks (MOFs). In this work, we have investigated the nonequilibrium bandgap modification in cobalt porphyrin-based MOF (Co-TCPP MOF) nanofilms through transient absorption spectroscopy. Our results reveal a captivating redshift–blueshift crossover in the nonequilibrium bandgap of Co-TCPP MOFs, with a staggering maximum shifting value of approximately 170 meV, achieved with an excitation fluence of 96 μJ/cm2. This phenomenon sets the stage for further investigations into harnessing nonequilibrium bandgap modification as a powerful tool for tailoring photocarrier properties. Another key facet of our research is the revelation that the bandgap modification effect observed in Co-TCPP MOFs is strongly dependent on the excitation fluence and is absent in disordered porphyrin molecules. This observation suggests a correlation between the bandgap modification and the amplified many-body interactions present within the ordered MOF structure, thus offering valuable insights into the intricate relationship between bandgap modification, excitation fluence, and ordered MOF structures.

Constructing Co4(SO4)4 Clusters within Metal-Organic Frameworks for Efficient Oxygen Electrocatalysis.

Multinuclear metal clusters are ideal candidates to catalyze small molecule activation reactions involving the transfer of multiple electrons. However, synthesizing active metal clusters is a big challenge. Herein, on constructing an unparalleled Co4(SO4)4 cluster within porphyrin-based metal-organic frameworks (MOFs) and the electrocatalytic features of such Co4(SO4)4 clusters for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is reported. The reaction of CoII sulfate and metal complexes of tetrakis(4-pyridyl)porphyrin under solvothermal conditions afforded Co4-M-MOFs (M═Co, Cu, and Zn). Crystallographic studies revealed that these Co4-M-MOFs have the same framework structure, having the Co4(SO4)4 clusters connected by metalloporphyrin units through Co─Npyridyl bonds. In the Co4(SO4)4 cluster, the four CoII ions are chemically and symmetrically equivalent and are each coordinated with four sulfate O atoms to give a distorted cube-like structure. Electrocatalytic studies showed that these Co4-M-MOFs are all active for electrocatalytic OER and ORR. Importantly, by regulating the activity of the metalloporphyrin units, it is confirmed that the Co4(SO4)4 cluster is active for oxygen electrocatalysis. With the use of Co porphyrins as connecting units, Co4-Co-MOF displays the highest electrocatalytic activity in this series of MOFs by showing a 10mAcm-2 OER current density at 357mV overpotential and an ORR half-wave potential at 0.83V versus reversible hydrogen electrode (RHE). Theoretical studies revealed the synergistic effect of two proximal Co atoms in the Co4(SO4)4 cluster in OER by facilitating the formation of O─O bonds. This work is of fundamental significance to present the construction of Co4(SO4)4 clusters in framework structures for oxygen electrocatalysis and to demonstrate the cooperation between two proximal Co atoms in such clusters during the O─O bond formation process.

Virucidal activity of porphyrin-based metal-organic frameworks against highly pathogenic coronaviruses and hepatitis C virus

The antiviral effect of four porphyrin-based Metal-Organic Frameworks (PMOFs) with Al and Zr, namely Al-TCPP, PCN-222, PCN-223 and PCN-224 was assessed for the first time against HCoV-229E, two highly pathogenic coronaviruses (SARS-CoV-2 and MERS-CoV) and hepatitis C virus (HCV). Infection tests in vitro were done under dark or light exposure for different contact times, and it was found that 15 min of light exposure were enough to give antiviral properties to the materials, therefore inactivating HCoV-229E by 99.98 % and 99.96 % for Al-TCPP and PCN-222. Al-TCPP diminished the viral titer of SARS-CoV-2 greater than PCN-222 in the same duration of light exposure, having an effect of 99.95 % and 93.48 % respectively. Next, Al-TCPP was chosen as the best candidate possessing antiviral properties and was tested against MERS-CoV and HCV, showcasing a reduction of infectivity of 99.28 % and 98.15 % respectively for each virus. The mechanism of the antiviral activity of the four PMOFs was found to be the production of singlet oxygen 1O2 from the porphyrin ligand TCPP when exposed to visible light, by using sodium azide (NaN3) as a scavenger, that can later attack the phospholipids on the envelope of the viruses, thus preventing their entry into the cells.

Improving the Photoactivity of Porphyrin-Based Metal-Organic Frameworks via Constructing [Ce-O] Active Site and Vacancy.

Defect engineering of metal-organic frameworks (MOFs) is a versatile approach to tailoring their electronic structures and photocatalytic performance. Herein, Ce-based porphyrin MOFs (CMFs) featuring controlled structural defects were successfully prepared using a simple acid modulation strategy to drive the photocatalytic H2 generation. The [Ce-O] unit serves as the active site via a ligand-to-metal charge transfer process, which has been confirmed by in situ XPS analysis. Abundant exposed coordinatively unsaturated Ce-O centers are beneficial for the adsorption and activation of water molecules, which is an important factor for improving the photocatalytic performance of the synthesized defective MOFs. In addition, optical and electrochemical experiments indicate that CMFs with more oxygen vacancies possess higher charge separation efficiency. As a result, the optimized CMF(Zn)-200 sample afforded high stability and activity in the H2 generation (up to 1603.3 μmol·g-1·h-1 under cocatalyst-free conditions) and tetracycline hydrochloride removal efficiency (97%), which was 8.45 and 97 times higher than that of pure meso-tetra(4-carboxyphenyl)porphine. This study demonstrates that effective structural modulation and defect introduction can improve the activity and stability of PMOF-based photocatalysts.

Novel self-powered anti-interference photoelectrochemical sensor via zirconium porphyrin-based metal–organic framework as multifunctional signal label for oxytetracycline detection in food and environment

As a newly developed sensing mode, self-powered PEC sensing may successfully address issues like individual photoanode or photocathode sensing with poor signal responsiveness and weak anti-interference capacity. Herein, a self-powered PEC sensor was developed to detect oxytetracycline (OTC) by integrating SnS2/Sb2S3 photoanode with Cu2O photocathode, and zirconium porphyrin-based metal–organic framework (ZPM) as multifunctional signal label to achieve signal amplification. The highly efficient and stable self-powered biosensor not only delivers a sustained and robust photocurrent response for bioanalysis, thanks to its well-designed stepped band structure, but also successfully mitigates interference from reducing agents. Furthermore, the ZPM was firstly used as a multifunctional nano label in PEC biosensing platform. On the one hand, the ZPM has a large specific surface area and abundant functional groups that can be used to immobilize the aptamer. On the other hand, because of steric hindrance, poor conductivity, competition for dissolved oxygen and light source with the substrate, the ZPM can as photocathode quenching source to affect the photocurrent response. In optimized experimental conditions, the fabricated PEC sensing platform showed a broad linear range of 0.1 pM to 100 nM for assay of OTC with a low limit of detection (LOD=0.03 pM), coupled by its quantification in human serum samples with acceptable results. This work provides an avenue for the development of high-performance photoelectrochemical materials and opens up the possibility of designing more sensitive self-powered PEC biosensors.

Optically Mediated Nonvolatile Resistive Memory Device Based on Metal-Organic Frameworks.

Metal-organic frameworks (MOFs), characterized by tunable porosity, high surface area, and diverse chemical compositions, offer unique prospects for applications in optoelectronic devices. However, the prevailing research on thin-film devices utilizing MOFs has predominantly focused on aspects such as information storage and photosensitivity, often neglecting the integration of the advantages inherent in both photonics and electronics to enhance optical memory. This work demonstrates a light-mediated resistive memory device based on a highly oriented porphyrin-based MOFs film, in which the resistance state of the memristor is modulated by light, realizing the integration of the perception and storage of optical information. The memristor shows excellent performance with a wide light range of 405-785nm and a persistent photoconductivity phenomenon up to 8.3 × 103 s. Further mechanistic studies have revealed that the resistive switching effect in the memristor is primarily associated with the reversible formation and annihilation of Ag conductive filaments.

Innovative two-dimensional porphyrin-integrated metal-organic frameworks for enhanced photocatalytic hydrogen peroxide generation in pure water

In the quest for eco-friendly and efficient synthesis of hydrogen peroxide (H2O2), a chemical with extensive applications, photocatalytic production emerges as a promising clean technique. Metal-organic frameworks (MOFs), known for their exceptional porosity and geometric customizability, stand at the forefront of potential photocatalytic materials. Yet, the conventional three-dimensional topologies of MOFs pose a challenge, impeding the swift transit of photogenerated electrons and thereby curbing performance enhancements. In this vein, we have engineered novel 2D porphyrin-based MOFs, specifically Ce-TCPP and La-TCPP, utilizing diverse metal sources while maintaining a consistent topological framework. This design strategy streamlines the electron and hole transport pathways, thus elevating the photocatalytic activity. Delving into the structural nuances of these MOFs, our research unveiled that the photocatalytic activity experienced a marked shift upon altering the metal cluster types. Notably, La-TCPP, as an efficacious catalyst, demonstrated an H2O2 yield of 79.75 μmol/g/h in pure water, sans any sacrificial agents. Rigorous testing confirmed the robust stability of both MOFs. This study marks the inaugural design and synthesis of a single crystal structure of La-TCPP. By strategically varying metal cluster compositions, we have fine-tuned the architecture of two-dimensional MOFs. This approach sheds light on the intricate structure-activity relationship governing the photocatalytic synthesis of H2O2, paving the way for future advancements in the field.

Photoelectric active copper/iron porphyrin-based metal–organic framework embedded with ferric oxide nanocrystals for photoelectrochemical aptasensing miRNA-141 and in vivo tumor magnetic resonance imaging

A heterostructure of bimetallic copper/ferric metal–organic framework embedded with ferric oxide (denoted as Fe2O3@CuFe-MOF) nanocrystals was simultaneously employed as the bioplatform for constructing the photoelectrochemical (PEC) aptasensor to detect miRNA-141 and an excellent contrast agent for in vivo diagnosis cancer via magnetic resonance imaging (MRI). Fe2O3@CuFe-MOF was synthesized by linking 5,10,15,20-tetra(4-pyridyl)porphyrin (TPyP) with Cu2+ and Fe2+ ions, while partial Fe2+ ions were oxidized to Fe2O3 nanocrystals and embraced within CuFe-MOF (denoted as Fe2O3@CuFe-TPyP-MOF). Comparing with Cu-TPyP-MOF and Fe2O3@Fe-TPyP-MOF, Fe2O3@CuFe-TPyP-MOF exhibited enhanced separation ability of photocarriers, promoted electron transfer, larger specific surface area, and richer functionality, rendering boosted photoelectric conversion efficiency and superior PEC performance. The Fe2O3@CuFe-TPyP-MOF-based PEC aptasensor thus illustrated an ultralow limit of detection (0.8 fM) toward miRNA-141 within a wide range from 1.0 fM to 1.0 nM, accompanying with other outperformed aptasensing ability. In addition, due to the paramagnetic property of Cu2+ and Fe2+ ions, Fe2O3@CuFe-TPyP-MOF also afforded the promoted T1-weighted MRI imaging ability, showing the potential for the diagnosis of prostate tumor in vivo. This work provides a robust photoelectronic active MOF-based heterostructure for the sensitive detection and early cancer diagnosis.

Unveiling Advancements: Trends and Hotspots of Metal-Organic Frameworks in Photocatalytic CO2 Reduction.

Metal-organic frameworks (MOFs) are robust, crystalline, and porous materials featured by their superior CO2 adsorption capacity, tunable energy band structure, and enhanced photovoltaic conversion efficiency, making them highly promising for photocatalytic CO2 reduction reaction (PCO2RR). This study presents a comprehensive examination of the advancements in MOFs-based PCO2RR field spanning the period from 2011 to 2023. Employing bibliometric analysis, the paper scrutinizes the widely adopted terminology and citation patterns, elucidating trends in publication, leading research entities, and the thematic evolution within the field. The findings highlight a period of rapid expansion and increasing interdisciplinary integration, with extensive international and institutional collaboration. A notable emphasis on significant research clusters and key terminologies identified through co-occurrence network analysis, highlighting predominant research on MOFs such as UiO, MIL, ZIF, porphyrin-based MOFs, their composites, and the hybridization with photosensitizers and molecular catalysts. Furthermore, prospective design approaches for catalysts are explored, encompassing single-atom catalysts (SACs), interfacial interaction enhancement, novel MOF constructions, biocatalysis, etc. It also delves into potential avenues for scaling these materials from the laboratory to industrial applications, underlining the primary technical challenges that need to be overcome to facilitate the broader application and development of MOFs-based PCO2RR technologies.

Tumor targeted porphyrin-based metal–organic framework for photodynamic and checkpoint blockade immunotherapy

Photodynamic therapy (PDT) has become a promising approach and non-invasive modality for cancer treatment, however the therapeutic effect of PDT is limited in tumor metastasis and local recurrence. Herein, a tumor targeted nanomedicine (designated as PCN@HA) is constructed for enhanced PDT against tumors. By modified with hyaluronic acid (HA), which could target the CD44 receptor that expressed on the cancer cells, the targeting ability of PCN@HA has been enhanced. Under light irradiation, PCN@HA can produce cytotoxic singlet oxygen (1O2) and kill cancer cells, then eliminate tumors. Furthermore, PCN@HA exhibits fluorescence (FL)/ photoacoustic (PA) effects for multimodal imaging-guided cancer treatment. And PCN@HA-mediated PDT also can induce immunogenic cell death (ICD) and stimulate adaptive immune responses by releasing of tumor antigens. By combining with anti-PD-L1 checkpoint blockade therapy, it can not only effectively suppress the growth of primary tumor, but also inhibit the metastatic tumor growth.

Rapid screening of drugs in environmental water using metal organic framework/Ti3C2Tx composite coated blade spray-mass spectrometry

Simultaneous rapid screening of multiple drugs of abuse in environmental water facilitates effective monitoring and trend assessments. Herein, a novel porphyrin-based metal organic frameworks modified Ti3C2Tx nanosheets (Cu-TCPP/Ti3C2Tx) composite was prepared and utilized as solid-phase microextraction (SPME) coating for the simultaneous analysis of 21 drugs from water samples. The composite was embedded with matrix-compatible polyacrylonitrile binder to prepare a coated blade with thin and uniform coating layer. Ambient mass spectrometry (MS) technique was used to create a coated blade spray-MS (CBS-MS) method for the quantitative determination of drugs in water samples. High throughput and automated sample preparation were achieved with the use of a Concept 96-well plate system, enabling analysis of 21 drugs of abuse within 1 min per sample, while using only 8 µL of organic solvent for desorption and CBS-MS detection. The developed method showed favorable linearity (R2 ≥ 0.9983) in the range of 0.05 to 10 ng mL−1, low limits of detection (1.5–9.0 ng L-1), sufficient recovery (67.6–133.2%), as well as satisfactory precision (RSDs≤13.5%). This study not only delivers a novel and efficient SPME coating composite, but also demonstrates the excellent performance of a high-throughput, efficient, and green analytical method for determination of drugs in environmental water.

Ionic Liquid Modified Fe-Porphyrinic Metal-Organic Frameworks as Efficient and Selective Photocatalysts for CO2 Reduction.

Porphyrin-based metal-organic frameworks (MOFs) are ideal platforms for heterogeneous photocatalysts toward CO2 reduction. To further explore photocatalytic MOF systems, it is also necessary to consider their ability to fine-tune the microenvironments of the active sites, which affects their overall catalytic operation. Herein, a kind of ionic liquid (IL, here is 3-butyric acid-1-methyl imidazolium bromide, BAMeImBr) was anchored to iron-porphyrinic Zr-MOFs with different amounts to obtain ILx@MOF-526 (MOF-526 = Zr6O4(OH)4(FeTCBPP)3, FeTCBPP = iron 5,10,15,20-tetra[4-(4'-carboxyphenyl)phenyl]-porphyrin, x = 100, 200, and 400). ILx@MOF-526 series was designed to investigate the effects of the microenvironmental and electronic structural modification on the efficiency and selectivity of the photochemical reduction of CO2 after introducing IL fragments. Compared to parent MOF-526, the production and selectivity of CO were greatly improved in the absence of any photosensitizer under visible light by the ILx@MOF-526 series. Among them, the CO yield of IL200@MOF-526 was up to 14.0 mmol g-1 within 72 h with a remarkable CO selectivity of 97%, which is superior to that of MOF-526 without BAMeIm+ modification and other amounts of BAMeIm+ loaded. Furthermore, density functional theory calculations were performed to study the mechanism of the CO2 reduction.

Boosting persulfate activation through efficient π → π* transition activated by Cu ion anchored porphyrin-based metal–organic framework

Photocatalytic persulfate activation provides a promising approach for the elimination of persistent organic pollutants from water. This has been exemplified in porphyrin-based metal organic frameworks (PMOFs), which however come with ineffective electron transition within the porphyrin ligand. Herein, we present a Cu ion modification strategy capable of boosting electron transition by inducing electron delocalization under visible light. The introduction of Cu ions increased the degradation rate constant of ciprofloxacin (CIP) by nearly 44 times, surpassing most state-of-the-art photocatalysts. The in-situ characterizations and theoretical calculations suggest that π-electron localization constitutes the origin of ineffective electron transition in PMOFs. The introduction of Cu ions induces π-electron delocalization to intensify the π → π* transition, forming electron-rich centers of Cu to lower the energy barrier for O-O bond cleavage. This work offers fundamental insights into the electron transition within PMOFs, upon which the universal strategy is proposed for improved water decontamination performance via persulfate activation.

Porphyrin Metal-organic Framework Sensors for Chemical and Biological Sensing.

Porphyrins and porphyrin derivatives have been intensively explored for a number of applications such as sensing, catalysis, adsorption, and photocatalysis due to their outstanding photophysical properties. Their usage in sensing applications, however, is limited by intrinsic defects such as physiological instability and self-quenching. To reduce self-quenching susceptibility, researchers have developed porphyrin metal-organic frameworks (MOFs). Metal-organic frameworks (MOFs), a unique type of hybrid porous coordination polymers comprised of metal ions linked by organic linkers, are gaining popularity. Porphyrin molecules can be integrated into MOFs or employed as organic linkers in the production of MOFs. Porphyrin-based MOFs are a separate branch of the huge MOF family that combines the distinguishing qualities of porphyrins (e.g., fluorescent nature) and MOFs (e.g., high surface area, high porosity) to enable sensing applications with higher sensitivity, specificity, and extended target range. The key synthesis techniques for porphyrin-based MOFs, such as porphyrin@MOFs, porphyrinic MOFs, and composite porphyrinic MOFs, are outlined in this review article. This review article focuses on current advances and breakthroughs in the field of porphyrin-based MOFs for detecting a variety of targets (for example, metal ions, anions, explosives, biomolecules, pH, and toxins). Finally, the issues and potential future uses of this class of emerging materials for sensing applications are reviewed.