Highly Stable Zr(IV)-Based Metal-Organic Frameworks for the Detection and Removal of Antibiotics and Organic Explosives in Water

Two three-dimensional coordination polymers as fluorescence probes for the detection of nitrobenzene, tetracycline, fluazinam and their application in green pepper

Two coordination polymers (CPs), [Zn5(L)2(phen)5](1) and [Cd2(HL)(2,2-bpy)(H2O)3](2), were synthesized by using 2',3,3',5,5'-Diphenyl ether pentacarboxylic acid (H5L), phenanthroline (phen), and 2,2'-bipyridine (2,2'-bpy) under hydrothermal conditions. The L5- ligand adopts the μ6-к2: к2: к1: к1: к1: к1 mode in 1 and the μ5-к2: к2: к2: к2: к1 mode in 2. Sensing experiments show that 1 and 2 are fluorescence probes with high sensitivity and rapid detection of nitro explosives, antibiotics, and pesticides. In order to verify the ability of 2 to detect FLU in actual samples, we performed a spiked recovery experiment in green pepper water. The spiked recoveries were 97.77-101.18 %. Interestingly, because H5L is not completely deprotonated in 2, there is abundant hydrogen bonding, which makes the fluorescence quenching rate higher and the detection limit lower. The possible fluorescence quenching mechanism of 1 and 2 can be explained by their UV-VIS absorption spectra and orbital energy levels.

Synthesis of highly sensitive and multi-response Eu-MOF, fluorescence sensing properties and anti-counterfeiting applications

A new Europium metal-organic framework (Eu-MOF), namely [Eu(dpa) (H2O)]·0.5(bpy)·4H2O}n (H4dpa = 5-(3,4-dicarboxyphenoxy) isophenic acid, bpy = protonated 4,4'-bipyridine) was synthesized and structurally characterized by elemental analyses, infrared spectroscopy, and X-ray single-crystal diffraction analyses. Eu-MOF shows a three-dimensional network structure based on EuIII ions and (dpa)4- ligands via µ4: η1, η2, η2, η2 coordination mode. Fluorescence analysis shows that Eu-MOF has excellent fluorescence sensing characteristics, which can efficiently and sensitively detect various pollutants in water: the limit of detection (LOD) of ratiometric fluorescence detection of ANI in water was 42.9 nM, which was better than the single-peak detection limit. In addition, the peak detection limits of Eu-MOF for Flu, ORN and NB were 120 nM, 27 nM and 94 nM, respectively. In addition, XPS, LUMO orbital energy level, fluorescence lifetime, ultraviolet absorption and other principles are used to explore the mechanism of fluorescence quenching. Surprisingly, Eu-MOF not only has excellent anti- counterfeiting ability and stability, can be used as anti-counterfeiting material in life, but also has good selectivity to Flu. Eu-MOF has obvious fluorescence quenching effect on Flu on paper under ultraviolet light, which can be used for rapid in situ imaging test paper of pesticide residues.

Rationally design a novel Zn-MOF for fluorescent detection of nitrofuran antibiotics: The synthesis, structure and sensing applications

Nitrofuran antibiotics (NFAs) residues in waterare a persistent concern for the public due to the potential threats they pose to human health and the environment. Therefore, efficient probes that are capable of detecting trace amounts of antibiotics in real water environments have become a top priority. Herein, a novel fluorescent Zn-MOF probe (MOF-1) was revealed for the highly selective and sensitive sensing of NFAs. MOF-1 was rationally constructed with Zn(NO3)2·6H2O, 5,5'-(anthracene-9,10-diyl) diisophthalic acid (H4ADIP) and 1,3-bis(imidazol-1-ylmethyl)-benzene (mbib) by using the solvothermal method. Fluorescence sensing experiments demonstrate that MOF-1 can function as a fluorescent sensor for selective, sensitive, and rapid detection of NFAs among 15 antibiotics including ciprofloxacin (CPFX), chloramphenicol (CAP), sulfonamides and NFAs. Fluorescence titration experiments indicated that MOF-1 exhibited remarkably low detection limits of 0.19 μM, 0.26 μM, and 0.34 μM for furazolidone (FZD), furaltadone (FDH) and nitrofurazone (NFZ), respectively. Meanwhile, MOF-1 was successfully employed for NFAs detection in real samples with the recoveries of 98.7 % - 104.1 %, and a relative standard deviation below 5.1 %. Moreover, the sensing mechanism could be ascribed to the synergistic effect between the internal filtering effect and photoinduced electron transfer according to the experiment results and DFT calculations. Additionally, test strips were prepared based on MOF-1 for point of care testing of NFAs.

Construction of luminescent dye@MOF platforms for sensing antibiotics with enhanced selectivity and sensitivity

The fabrication of luminescent dye@MOF composites has received extensive attentions in the development of realistic sensing applications. Herein, based on two anionic In-MOFs with different pore structure (1 and 2), the charge and size dependent ion-exchange of cationic dyes was investigated, and consequently four luminescent dye@MOF composites (DMASM@1/2 and RhB@1/2) were successfully fabricated and importantly can be regarded as ideal platforms for better understanding of the factors affecting the construction of dye@MOF composites, which may closely related to a well match between the intrinsic properties and size/charge of the fluorescent molecules and the porosity, structure character of the MOF hosts. Furthermore, these four dye@MOF composites were utilized for sensing of different kinds of antibiotics, demonstrating enhanced selectivity and sensitivity. DMASM@1/2 demonstrated excellent selectivity and sensitivity for NFT and NFZ antibiotics, while RhB@1/2 exhibited excellent selectivity and sensitivity for MDZ and DTZ antibiotics. Systematic analysis of the detection mechanism revealed that different energy transfer efficiency and interaction between MOF frameworks and different types of guest dyes led to different selectivity and detection mechanisms for antibiotics. Moreover, high selectivity and sensitivity, low LOD and extraordinary recycling capacity of four dye@MOF composites in the detection of antibiotics promote their excellent prospect in the further practical application.

Luminescent Metal-Organic Framework-Based Fluorescent Sensor Array for Screening and Discrimination of Bisphenols

Extensive applications of bisphenols in industrial products have led to their release into aquatic environments, causing a great threat to human health due to their endocrine-disrupting effects, whereas existing methods are difficult to implement the rapid and high-throughput detection of multiple bisphenols. To circumvent this issue, we constructed a sensor array using two luminescent metal-organic frameworks (LMOFs) (Zr-BUT-12 and Ga-MIL-61) for the rapid discrimination of six bisphenol contaminants (BPA, BPS, BPB, BPF, BPAF, and TBBPA). Wherein, Zr-BUT-12 and Ga-MIL-61 exhibited different fluorescence-emission properties and good luminescent stability. Interestingly, bisphenols with different structures had diverse quenching effects on the fluorescence intensity of Zr-BUT-12 and Ga-MIL-61 via the adsorptive interaction, resulting in unique fluorescent fingerprints. Based on pattern recognition methods, different bisphenols were successfully identified, with the limit of detection in the range of 1.59-16.7 ng/mL for six bisphenols. More importantly, the developed sensor array could be effectively utilized for distinguishing different ratios of mixed bisphenols, which was further applied for bisphenol discrimination in real water samples. Consequently, our finding provides a promising strategy for the simultaneous recognition of multiple bisphenols, which encourages the development of a sensor array for the detection of multiple contaminants in environmental monitoring and food safety.

Two Stable Pillar-Layered Zn-LMOFs for Highly Fluorescence Sensing of Inorganic Pollutants and Nitro Aromatic Compounds in Water

Luminescent metal-organic frameworks (LMOFs) are a potential class of functional materials for the photoluminescent detection of a wide range of analytes as well as for the detection of pollutants in wastewater. Herein, by using the pillar-layered strategy, two new luminescence Zn-LMOFs (JLU-MOF222 and JLU-MOF223) were successfully solvothermal synthesized. The 2D layers are both consisting of Zn2+ and TPHC [TPHC = (1,1':2',1″-terphenyl)-3,3″,4,4',4″,5'-hexacarboxylic acid] ligands and then pillared by the different N-donor ligands to form the 3D Zn-LMOFs with fsh topology. Benefiting from the uncoordinated carboxylate sites, uncoordinated N atom, or -NH2 group in the pillaring ligands and excellent stability in pH = 2-13 aqueous phase, JLU-MOF222 and JLU-MOF223 not only can sensitively detect trace amounts of inorganic pollutants (Fe3+, Cr2O72-) and nitro aromatic compounds TNP and 2,4-DNP (TNP = 2,4,6- trinitrophenol, 2,4-DNP = 2,4-dinitrophenol) through luminescence quenching but also exhibit high selectivity of other anti-interference competing analytes. The two new Zn-LMOFs can be used as potential luminescent sensors for pollutant detection in water due to their high KSV and low limit of detection (LOD).

Experimental and Theoretical Elucidation of the Luminescence Quenching Mechanism in Highly Efficient Hg2+ and Sulfadiazine Sensing by Ln-MOF

Heavy metal ions and antibiotic contamination have become a major environmental concern worldwide. The development of efficient recognition strategies of these pollutants at ultra-low concentrations in aqueous solutions as well as the elucidation of the intrinsic sensing mechanism are challenging tasks. In this work, unique luminescent Ln-MOF materials (NIIC-3-Ln) were assembled by rational ligand design. Among them, NIIC-3-Tb demonstrated highly selective luminescence quenching response toward Hg2+ and sulfadiazine (SDI) at subnanomolar concentrations in less than 7 s. In addition, a Hg2+ sensing mechanism through chelation was proposed on the basis of single-crystal X-ray diffraction analysis and Hg2+ adsorption study. The interaction mechanism of NIIC-3-Tb with SDI was revealed using a newly developed approach involving a (TD-)DFT based quantification of the charge transfer of a MOF-analyte supramolecular complex model in the ground and excited states. Effect of ultrasonic treatment on the surface morphology important for MOF sensing performance was revealed by gas adsorption experiments. The presented results indicate that NIIC-3-Ln is not only an advanced sensing material for the efficient detection of Hg2+ and SDI at ultra-low concentrations, but also opens up a new approach to study the sensing mechanism at the molecular level at ultra-low concentrations.

Bifunctional In-MOFs for Selective and Sensitive Detection of Trace Nitrobenzene Compounds in Water and Possessing High Proton Conductivity

With the escalating prevalence of terrorism and global environmental pollution, nitroaromatic compounds (NACs) have increasingly come into focus as the primary culprit. To counter these challenges, it is imperative to develop simple and efficient methods for detecting NACs. Considering the electron-deficient structure of NAC molecules, this paper constructed a novel three-dimensional In-MOF with permanent porosity using electron-rich organic molecules 4'-[1,2,2-tris(3',5'-dicarboxy[1,1'-biphenyl]-4-yl)ethenyl]-[1,1'-biphenyl]-3,5-dicarboxylic acid (H8ETTB) for fluorescence detection by photoinduced electron transfer. The results indicated that In-ETTB can sensitively detect trace NACs in water. In-ETTB exhibited the best detection performance for 3-NP, achieving a Ksv value of 8.75 × 104 M-1 with a limit of detection of 0.27 μΜ in aqueous solution; this belongs to a relatively high level among the reported metal organic framework (MOF) materials. Subsequently, anti-interference experiments revealed that In-ETTB exhibits strong specificity fluorescence recognition of NACs, and it could still maintain its structural integrity and fluorescence emission intensity even after 7 cycles of testing. We confirmed that the fluorescence detection of NACs was due to a combined effect of competitive absorption and photoinduced electron transfer through experimental collaboration DFT calculations in detail. Meanwhile, the proton conductivity reached 2.45 × 10-2 S·cm-1 at 98% relative humidity and 90 °C, which is also a high level in MOFs. This work provides a universal method theoretical basis for designing NAC detectors with practical application prospects.

Ultrahigh-sensitivity vinyl-COF fluorescent sensor for trace organic arsenic detection

Recently, the misuse of organic arsenic feed additives, such as roxarsone (ROX), has increasingly jeopardized both human health and the environment. In response, a unique electron-rich pyrazine-cored fluorescent covalent organic framework (COF) nanosheet, named as COF-TMP, was synthesized using an alkali-catalyzed reaction between 2, 3, 5, 6-tetramethylpyrazine (TMP) and terephthalaldehyde (TPA). Characterization demonstrated that COF-TMP boasted high porosity, pronounced fluorescence, and an abundance of (E)-2-styrylpyrazine (SPA) groups. These attributes render it an exceptional fluorescent sensor for the ultrahigh sensitivity detection of electron-deficient ROX molecules. The limit of detection (LOD) for COF-TMP in detecting ROX was found to be 0.015 ppb through fluorescence-quenching titration experiments-surpassing all previously reported fluorescent sensors. A combination of experimental results and theoretical calculations suggests that the extraordinary detection capability of COF-TMP for ROX arises from a static quenching mechanism. This study paves the way not only for a novel pyrazine-based fluorescent COF nanosheet with high porosity, exceptional fluorescent capabilities, and abundant SPA groups suitable for highly sensitive and selective ROX detection but also hints at its potential application as a fluorescent sensor for environmental pollution management and related domains.

Combined Effect of Hydrophilic Pore and the Type of Protons on Proton Conductivity in Porous Metal-Organic Frameworks: A Feasible Approach to Achieve a Super Proton Conductor under Hydrated Conditions

There has been a steady growth of interest in proton-conductive metal-organic frameworks (MOFs) due to their potential utility in proton-exchange membrane fuel cells. To attain a super proton conductivity (>1 × 10-2 S cm-1) in a MOF-based proton conductor is a key step toward practical application. Currently, most studies are focused on enhancing the proton conductivity of porous MOFs by controlling a single factor, such as the type of protons or hydrophilic pore or hydrogen bond. However, a limited contribution from a single factor cannot afford to remarkably increase the proton conductivity of the MOF and form a super proton conductor. Herein, we constructed two distinct porous MOFs, {(H3O+)4[Cu12(ci)12(OH)4(H2O)12]·3H2O·9DMF} (Cu-ci-3D, H2ci = 1H-indazole-5-carboxylic acid, DMF = N,N'-dimethylformamide) and {[Co(Hppca)2]·2HN(CH3)2·CH3OH·2H2O} (Co-ppca-2D, H2ppca = 5-(pyridin-3-yl)-1H-pyrazole-3-carboxylic acid), to tune their proton conductivities at high relative humidity (RH) using the combined effect of hydrophilic pore and the type of protons, ultimately achieving super proton conduction. Excitingly, Cu-ci-3D indeed harvests a super proton conductivity of 1.37 × 10-2 S cm-1 at 353 K and ∼97% RH, superior to some previously reported MOF-based proton conductors. The results present a unique perspective for developing high-performance MOF-based proton conductors and understanding their structure-performance relationships.

Reticular Chemistry Directed "One-Pot" Strategy to in situ Construct Organic Linkers and Zirconium-Organic Frameworks

Zirconium-based metal-organic frameworks (Zr-MOFs) have emerged as one of the most studied MOFs due to the unlimited numbers of organic linkers and the varying Zr-oxo clusters. However, the synthesis of carboxylic acids, especially multitopic carboxylic acids, is always a great challenge for the discovery of new Zr-MOFs. As an alternative approach, the in situ "one-pot" strategy can address this limitation, where the generation of organic linkers from the corresponding precursors and the sequential construction of MOFs are integrated into one solvothermal condition. Herein, inspired by benzimidazole-contained compounds synthesized via reaction of aldehyde and o-phenylenediamine, tri-, tetra-, penta- and hexa-topic carboxylic acids and a series of corresponding Zr-MOFs can be prepared via the in situ "one-pot" method under the same solvothermal conditions. This strategy can be utilized not only to prepare reported Zr-MOFs constructed using benzimidazole-contained linkers, but also to rationally design, construct and realize functionalities of zirconium-pentacarboxylate frameworks guided by reticular chemistry. More importantly, in situ "one-pot" method can facilitate the discovery of new Zr-MOFs, such as zirconium-hexacarboxylate frameworks. The present study demonstrates the promising potential of benzimidazole-inspired in situ "one-pot" approach in the crystal engineering of structure- and property-specific Zr-MOFs, especially with the guidance of reticular chemistry.

Fabrication of graphitic carbon nitride/gum Arabic/potassium carrageenan composite for efficient adsorption of erythromycin: Kinetic and thermodynamic studies

Erythromycin (ERY) molecules are robust to the environment and hard to remove due to their aromatic structure. Nowadays, numerous researches have reported that the ERY amount in water is above the standard level and its removal is necessary. Here, we prepared three solid adsorbents: graphitic carbon nitride (g-C3N4), potassium carrageenan beads (Cr), and graphitic carbon nitride/gum Arabic/potassium carrageenan composite (g-ACr). Several techniques such as XRD, SEM, TEM, TGA, ATR-FTIR, Zeta potential, and N2 adsorption were employed to characterize the fabricated adsorbents. Five essential factors of adsorbent dose, initial ERY concentration, contact time, temperature, and pH were optimized to investigate the batch adsorption of ERY. The maximum adsorption capacity of 356.12 mg/g was attained by g-ACr composite at an adsorbent dose of 1.25 g/L, contact time of 6 h, and pH 7 at 15 °C. The data showed that the experimental findings exhibited the best agreement with Langmuir, Temkin, and DR isotherm models, in addition to the kinetic models of pseudo-second-order, Elovich, and intra-particle diffusion. The evaluated thermodynamic factors designated that the ERY adsorption is endothermic, physisorption, favorable, and spontaneous process. The g-ACr reusability displayed a decline in the adsorption capacity after seven adsorption/desorption runs by 5.7 %. Finally, this work outcomes depict that g-ACr composite is an efficient reusable adsorbent for ERY elimination from wastewater.

Synthesis of pyridyl functionalized 3-pyrrolyl BODIPY based fluoroprobes and application towards highly selective detection of picric acid

A series of pyridyl-coupled 3-pyrrolyl BODIPY fluoroprobes were synthesized by varying the position of the pyridyl/N-methylated pyridyl group at the α-/meso-position of the 3-pyrrolyl BODIPY scaffold and thoroughly characterized by HRMS and 1D/2D NMR techniques. Our studies indicated that only the water-soluble N-methylated p-pyridyl 3-pyrrolyl BODIPY among various pyridyl-coupled 3-pyrrolyl BODIPYs synthesized here showed an effective and exclusive sensing for picric acid (HPA). The N-methylated p-pyridyl 3-pyrrolyl BODIPY rapidly detects HPA in an aqueous medium with exceptional selectivity, sensitivity (LOD = 7.90 pM), and high binding affinity (Ka = 4·94 × 108 M-1) through both chromogenic and fluorogenic signalling modes. Our studies support the formation of a charge transfer complex between cationic N-methylated p-pyridyl 3-pyrrolyl BODIPY and picrate as verified by absorption, fluorescence, electrochemical, and NMR techniques. DFT and TD-DFT studies further support the structural and experimental observations, including the sensing mechanism of HPA.

Research progress of fluorescent composites based on cyclodextrins: Preparation strategies, fluorescence properties and applications in sensing and bioimaging

Fluorescence analysis has been regarded as one of the commonly used analytical methods because of its advantages of simple operation, fast response, low cost and high sensitivity. So far, various fluorescent probes, with noble metal nanoclusters, quantum dots, organic dyes and metal organic frameworks as representatives, have been widely reported. However, single fluorescent probe often suffers from some deficiencies, such as low quantum yield, poor chemical stability, low water solubility and toxicity. To overcome these disadvantages, the introduction of cyclodextrins into fluorescent probes has become a fascinating approach. This review (with 218 references) systematically covers the research progress of fluorescent composites based on cyclodextrins in recent years. Preparation strategies, fluorescence properties, response mechanisms and applications in sensing (ions, organic pollutants, bio-related molecules, temperature, pH) and bioimaging of fluorescent composites based on cyclodextrins are summarized in detail. Finally, the current challenges and future perspectives of these composites in relative research fields are discussed.

Highly thermostable RhB@Zr-Eddc for the selective sensing of nitrofurazone and efficient white light emitting diode

Highly thermostable RhB@Zr-Eddc composites with the Rhodamine B (RhB) enclosed into the nanocages of Zr-Eddc was synthesized by one-pot method under hydrothermal conditions, whose structure, morphology and stability were characterized through the X-ray powder diffractometry (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). RhB@Zr-Eddc showed the highly thermal stability up to 550°C and emitted the bright red-light emission at 605 nm, which could highly selective detect the nitrofurazone (NFZ) among eleven other antibiotics in aqueous solution. Furthermore, via combining the RhB@Zr-Eddc with commercial green phosphor (Y3Al5O12:Ce3+, Ga3+), the mixture was encapsulated onto a 455 nm blue LED chip, creating an ex-cellent white light emitting diode (WLED) device with the correlated colour temperature (CCT) of 4710 K, luminous efficiency (LE) of 43.17 lm/w and Color Rendering Index (CRI) of 89.2.

Dual-functional metal-organic framework for chemisorption and colorimetric monitoring of cyanogen chloride

Given the growing concern over the deployment of toxic chemicals in warfare, the rapid and accurate removal and detection of cyanogen chloride (CK) as a blood agent has become increasingly critical. However, conventional physisorbents and chemisorbents used in military respirators are insufficient for the effective removal of CK. In this study, we demonstrate the chemisorption and sensing abilities of Co2(m-DOBDC) (m-DOBDC4- = 4,6-dioxo-1,3-benzenedicarboxylate) for CK via electrophilic aromatic substitution (EAS) in humid environments. Unlike the chemisorption in triethylenediamine (TEDA) impregnated carbon materials, which generates by-products through hydrolysis, the electron-rich C5 sites in m-DOBDC4- ligands give rise to cyano substitution with CK. This leads to the formation of stable C-C bonds and chloride ions (Cl-) coordinating with open Co2+ sites. Such a mechanism prevents the generation of toxic by-products like cyanic acid and hydrochloric acid. Breakthrough experiments conducted in a packed-bed system conclusively demonstrated the superior CK removal capacity of Co2(m-DOBDC) (1662 min/g), compared to TEDA-impregnated activated carbon (323 min/g) under humid conditions. Considering that MOF-74 series, isostructural with Co2(m-DOBDC), barely adsorb CK under similar conditions, this finding marks a significant advancement in developing novel sorbents for CK removal. Moreover, this chemisorption not only exhibited rapid and highly efficient CK removal but also enabled colorimetric monitoring via the distinctive color change induced by the coordination of Cl- acting as σ donors. These findings facilitate the development of adsorption and sensing equipment to protect military personnel from toxic chemical threats.

Advances in Functionalized Biocomposites of Living Cells Combined with Metal-Organic Frameworks

Motivated by the remarkable innate characteristics of cells in living organisms, we have found that hybrid materials that combine bioorganisms with nanomaterials have significantly propelled advancements in industrial applications. However, the practical deployment of unmodified living entities is inherently limited due to their sensitivity to environmental fluctuations. To surmount these challenges, an efficacious strategy for the biomimetic mineralization of living organisms with nanomaterials has emerged, demonstrating extraordinary potential in biotechnology. Among them, innovative composites have been engineered by enveloping bioorganisms with a metal-organic framework (MOF) coating. This review systematically summarizes the latest developments in living cells/MOF-based composites, detailing the methodologies employed in structure fabrication and their diverse applications, such as bioentity preservation, sensing, catalysis, photoluminescence, and drug delivery. Moreover, the synergistic benefits arising from the individual compounds are elucidated. This review aspires to illuminate new prospects for fabricating living cells/MOF composites and concludes with a perspective on the prevailing challenges and impending opportunities for future research in this field.

Wearable, Biocompatible, and Dual-Emission Ocular Multisensor Patch for Continuous Profiling of Fluoroquinolone Antibiotics in Tears

The abuse or misuse of antibiotics in clinical and agricultural settings severely endangers human health and ecosystems, which has raised profound concerns for public health worldwide. Trace detection and reliable discrimination of commonly used fluoroquinolone (FQ) antibiotics and their analogues have consequently become urgent to guide the rational use of antibiotic medicines and deliver efficient treatments for associated diseases. Herein, we report a wearable eye patch integrated with a quadruplex nanosensor chip for noninvasive detection and discrimination of primary FQ antibiotics in tears during routine eyedrop treatment. A set of dual-mode fluorescent nanoprobes of red- or green-emitting CdTe quantum dots integrated with lanthanide ions and a sensitizer, adenosine monophosphate, were constructed to provide an enhanced fluorescence up to 45-fold and nanomolar sensitivity toward major FQs owing to the aggregation-regulated antenna effect. The aggregation-driven, CdTe-Ln(III)-based microfluidic sensor chip is highly specific to FQ antibiotics against other non-FQ counterparts or biomolecular interfering species and is able to accurately discriminate nine types of FQ or non-FQ eyedrop suspensions using linear discriminant analysis. The prototyped wearable sensing detector has proven to be biocompatible and nontoxic to human tissues, which integrates the entire optical imaging modules into a miniaturized, smartphone-based platform for field use and reduces the overall assay time to ∼5 min. The practicability of the wearable eye patch was demonstrated through accurate quantification of antibiotics in a bactericidal event and the continuous profiling of FQ residues in tears after using a typical prescription antibiotic eyedrop. This technology provides a useful supplement to the toolbox for on-site and real-time examination and regulation of inappropriate daily drug use that might potentially lead to long-term antibiotic abuse and has great implications in advancing personal healthcare techniques for the regulation of daily medication therapy.

Evaluation of Open-Source Large Language Models for Metal-Organic Frameworks Research

Along with the development of machine learning, deep learning, and large language models (LLMs) such as GPT-4 (GPT: Generative Pre-Trained Transformer), artificial intelligence (AI) tools have been playing an increasingly important role in chemical and material research to facilitate the material screening and design. Despite the exciting progress of GPT-4 based AI research assistance, open-source LLMs have not gained much attention from the scientific community. This work primarily focused on metal-organic frameworks (MOFs) as a subdomain of chemistry and evaluated six top-rated open-source LLMs with a comprehensive set of tasks including MOFs knowledge, basic chemistry knowledge, in-depth chemistry knowledge, knowledge extraction, database reading, predicting material property, experiment design, computational scripts generation, guiding experiment, data analysis, and paper polishing, which covers the basic units of MOFs research. In general, these LLMs were capable of most of the tasks. Especially, Llama2-7B and ChatGLM2-6B were found to perform particularly well with moderate computational resources. Additionally, the performance of different parameter versions of the same model was compared, which revealed the superior performance of higher parameter versions.

A smartphone-integrated test paper sensing platform for visual and intelligent detection of nitrofurantoin in honey samples

The development of a rapid and convenient detection method for nitrofurantoin (NFT) residual is of great significance for food safety. Herein, a new fluorescent probe (Eu-TDCA-Phen) was developed for the visual and sensitive assay of NFT through the fluorescence quenching effect of inner filter effect (IFE) and photo-induced electron transfer (PET). The probe suspension demonstrates a wide linear range (0-0.16 mM), low detection limit (90 nM), high sensitivity, and rapid response time (2 min) in the "turn-off" process. To quantify the visual detection process, a smartphone-assisted test paper sensing platform was established and was applied for NFT determination in real honey samples, achieving satisfactory recovery rate ranges from 98.04 % to 105.04 %. Furthermore, a logic gate device was integrated with the sensing platform to streamline the visual detection process. The sensing platform offers several merits, including simpleness, quantification, portability and cost-effectiveness, making it highly suitable for real-time and on-site detection of antibiotics in food samples.

Rare [Cu4I2]2+ cationic cluster-based metal-organic framework and hierarchical porous composites design for effective detection and removal of roxarsone and antibiotics

Fluorescence quenching induced by photoinduced electron transfer (PET) stands as an effective strategy for identifying water pollutants. Herein, a novel (4, 8)-connected three-dimensional framework Cu(I)-MOF ([Cu2I(tpt)]n) with unique 8-connected [Cu4I2]2+ cationic clusters is designed by employing the nitrogen-rich ligand (Htpt = 5-[4(1H-1,2,4-triazol-1-yl)]phenyl-2H-tetrazole). Water-stabilized Cu(I)-MOF exhibits outstanding fluorescence properties, facilitating its application in detecting organic pollutants in water. Benefiting from the fact that the Cu(I)-MOF possesses a higher lowest unoccupied molecular orbitals (LUMO) energy level than that of the analyte, the rapid d-PET can occur, entitling Cu(I)-MOF to a sensitive fluorescence quenching response to roxarsone (ROX), nitrofurazone (NFZ) and nitrofurantoin (NFT) (with detection limits as low as 0.13 µM, 0.15 µM, and 0.13 µM, respectively). The nitrogen-containing sites of melamine foam (MF) are utilized to facilitate the anchoring and growth of Cu-MOF crystals, which enables the preparation of hierarchical microporous - macroporous Cu(I)-MOF/MF composites. The ordered porous structure of Cu(I)-MOF/MF provides cavities and open sites for the efficient removal of ROX (qmax = 210.6 mg∙g-1), NFZ (qmax = 111.5 mg∙g-1) and NFT (qmax = 238.9 mg∙g-1) from water. This characteristic endows the Cu(I)-MOF/MF with rapid and recyclable adsorption capacity. Therefore, this work provides valuable insights to address the problem of detection and removal of pollutants in the aquatic environment.

Mechanistical Insights into the Ultrasensitive Detection of Radioactive and Chemotoxic UO22+ Ions by a Porous Anionic Co-Metal-Organic Framework

Development of a simple, cost-efficient, and portable UO22+ sensory probe with high selectivity and sensitivity is highly desirable in the context of monitoring radioactive contaminants. Herein, we report a luminescent Co-based metal-organic framework (MOF), {[Me2NH2]0.5[Co(DATRz)0.5(NH2BDC)]·xG}n (1), equipped with abundant amino functionalities for the selective detection of uranyl cations. The ionic structure consists of two types of channels decorated with plentiful Lewis basic amino moieties, which trigger a stronger acid-base interaction with the diffused cationic units and thus can selectively quench the fluorescence intensity in the presence of other interfering ions. Furthermore, the limit of detection for selective UO22+ sensing was achieved to be as low as 0.13 μM (30.94 ppb) with rapid responsiveness and multiple recyclabilities, demonstrating its excellent efficacy. Density functional theory (DFT) calculations further unraveled the preferred binding sites of the UO22+ ions in the tubular channel of the MOF structure. Orbital hybridization between NH2BDC/DATRz and UO22+ together with its significantly large electron-accepting ability is identified as responsible for the luminescence quenching. More importantly, the prepared 1@PVDF {poly(vinylidene difluoride)} mixed-matrix membrane (MMM) displayed good fluorescence activity comparable to 1, which is of great significance for their practical employment as MOF-based luminosensors in real-world sensing application.

Knowledge graph and development hotspots of biochar as an emerging aquatic antibiotic remediator: A scientometric exploration based on VOSviewer and CiteSpace

As an emerging material in the field of environmental remediation, biochar produced by carbonisation of organic solid waste has been widely used in the remediation of antibiotic wastewater due to its environmental friendliness and excellent adsorption properties. This study analyses the current literature in the field in a comprehensive and scientific manner using CiteSpace and VOSviewer technologies. Between 2011 and 2023, a total of 1162 papers were published in this domain, spanning three distinct stages: applied methods, mechanism investigation, and enhanced improvement. The results of keyword clustering indicate that the remediation of antibiotics complexed with multiple pollutants by biochar is the main research topic, followed by the remediation of antibiotics by biochar in combination with other technologies. Furthermore, drawing from current research hotspots in antibiotic remediation using biochar, this study identified the pivotal mechanisms involved: (1) The primary mechanisms by which raw biochar remediates antibiotics include π-π electron donor-acceptor interactions, hydrophobic interactions, electrostatic interactions, hydrogen-bonding, and pore filling. (2) Steam activation, acid/base, metal salt/metal oxide, and clay mineral modification can improve the physical/chemical properties of biochar, enhancing its adsorptive removal of antibiotics. (3) Biochar activated persulfate and degraded antibiotics via free radical pathways (SO4-•, •OH and O2-•) as well as non-free radical pathways (1O2 and electron transfer). In addition, the challenge and prospect of biochar engineering applications for antibiotic remediation lies in improving the main mechanism of antibiotic remediation by biochar. The prospective utilization of biochar in enhancing the remediation of antibiotic-related pollutants holds tremendous value for the future.

Innovations and challenges in adsorption-based wastewater remediation: A comprehensive review

Water contamination is an escalating emergency confronting communities worldwide. While traditional adsorbents have laid the groundwork for effective water purification, their selectivity, capacity, and sustainability limitations have driven the search for more advanced solutions. Despite many technological advancements, economic, environmental, and regulatory hurdles challenge the practical application of advanced adsorption techniques in large-scale water treatment. Integrating nanotechnology, advanced material fabrication techniques, and data-driven design enabled by artificial intelligence (AI) and machine learning (ML) have led to a new generation of optimized, high-performance adsorbents. These advanced materials leverage properties like high surface area, tailored pore structures, and functionalized surfaces to capture diverse water contaminants efficiently. With a focus on sustainability and effectiveness, this review highlights the transformative potential of these advanced materials in setting new benchmarks for water purification technologies. This article delivers an in-depth exploration of the current landscape and future directions of adsorbent technology for water remediation, advocating for a multidisciplinary approach to overcome existing barriers in large-scale water treatment applications.

Distinguishing nitroimidazoles from nitrofurans via luminescence sensing

Similarity of nitroimidazole and nitrofuran antibiotics in molecular structure and photophysical properties makes them difficult to distinguish via luminescence sensing technology. Herein, this is solved by a dye-encapsulated lanthanide metal-organic framework luminescent sensor.

Powders to Thin Films: Advances in Conjugated Microporous Polymer Chemical Sensors

Chemical sensing of harmful species released either from natural or anthropogenic activities is critical to ensuring human safety and health. Over the last decade, conjugated microporous polymers (CMPs) have been proven to be potential sensor materials with the possibility of realizing sensing devices for practical applications. CMPs found to be unique among other porous materials such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) due to their high chemical/thermal stability, high surface area, microporosity, efficient host-guest interactions with the analyte, efficient exciton migration along the π-conjugated chains, and tailorable structure to target specific analytes. Several CMP-based optical, electrochemical, colorimetric, and ratiometric sensors with excellent selectivity and sensing performance were reported. This review comprehensively discusses the advances in CMP chemical sensors (powders and thin films) in the detection of nitroaromatic explosives, chemical warfare agents, anions, metal ions, biomolecules, iodine, and volatile organic compounds (VOCs), with simultaneous delineation of design strategy principles guiding the selectivity and sensitivity of CMP. Preceding this, various photophysical mechanisms responsible for chemical sensing are discussed in detail for convenience. Finally, future challenges to be addressed in the field of CMP chemical sensors are discussed.

Interior and Exterior Surface Modification of Zr-Based Metal-Organic Frameworks for Trace Benzene Removal

The emission of volatile organic compounds (VOCs) significantly contributes to air pollution and poses a serious threat to human health. Benzene, one of the most toxic VOCs, is difficult for the human body to metabolize and is classified as a Group 1 carcinogen. The development of efficient adsorbents for removing trace amounts of benzene from ambient air is thus of great importance. In this work, we studied the benzene adsorption properties of four Zr-based metal-organic frameworks (Zr-MOFs) through static volumetric and dynamic breakthrough experiments. Two previously reported Zr-MOFs, BUT-12 and STA-26, were prepared with a tritopic carboxylic acid ligand (H3L1) functionalized with three methyl groups, and STA-26 is a 2-fold interpenetrated network of BUT-12. Two new isoreticular Zr-MOFs, BUT-12-Et and STA-26-Et, were synthesized using a similar ligand, H3L2, where the methyl groups are replaced with ethyl groups. There are mesopores in BUT-12 and BUT-12-Et and micropores in STA-26 and STA-26-Et. The four Zr-MOFs all showed high stability in liquid water and acidic aqueous solutions. The microporous STA-26 and STA-26-Et showed much higher benzene uptakes than mesoporous BUT-12 and BUT-12-Et at room temperature under low pressures. Particularly, the benzene adsorption capacity of STA-26-Et was high up to 2.21 mmol/g at P/P0 = 0.001 (P0 = 12.78 kPa), higher than those of the other three Zr-MOFs and most reported solid adsorbents. Breakthrough experiments confirmed that STA-26-Et could effectively capture trace benzene (10 ppm) from dry air; however, its benzene capture capacity was reduced by 90% under humid conditions (RH = 50%). Coating of the crystals of STA-26-Et with polydimethylsiloxane (PDMS) increased the hydrophobicity of the exterior MOF surfaces, leading to a more than 2-fold improvement in its benzene capture capacity in the breakthrough experiment under humid condition. PDMS coating of STA-26-Et likely slowed down the water adsorption process, and thus, the adsorbent afforded more efficient capture of benzene. This work demonstrates that modifying both the interior and exterior surfaces of MOFs can effectively enhance their performance in capturing trace benzene from ambient air, even under humid conditions. This finding is meaningful for the development of new adsorbents for effective air purification applications.

Composite of a thiacalix[4]arene-copper(I) metal-organic framework and mesoporous carbon for efficient electrochemical detection of antibiotics

Abundant use of nitrofurantoin (NFT) and metronidazole (MTZ) antibiotics has led to excessive residues in the environments and humans, resulting in serious damage to the human body and ecosystem. Therefore, effective detection of NFT and MTZ is exceedingly necessary. In this regard, metal-organic frameworks (MOFs) are promising materials as electrochemical sensors. Herein, we synthesized a new two-dimensional thiacalix [4]arene-copper (I) MOF (Cu-TC4A-M). This MOF was mixed with mesoporous carbon (MC) to a give Cu-TC4A-M@MC composite. In addition, the sensors of Cu-TC4A-M@MC(2:1)/GCE and Cu-TC4A-M@MC(1:2)/GCE were achieved (GCE = glassy carbon electrode), and then were applied for effectively detecting NFT and MTZ, respectively. Markedly, the two sensors exhibited satisfactory linear detection range, anti-interference, reproducibility and stability. When they were utilized in the real samples, such as human serum, urine, tap water and lake water, satisfactory recoveries were attained. The relative standard deviations (RSDs) were in the range of 1.16 % ∼ 1.92 % for NFT and 0.95 % ∼ 2.33 % for MTZ. This work provided a new application prospect for the thiacalix [4]arene-based MOFs as promising candidate materials for NFT and MTZ detection.

Ultrathin Dielectric Triggered Charge Injection Dynamics for High-Performance Metal Organic Framework/MXene Supercapacitors

A MOF-MXene-BN three-component heterostructure exhibits impressive pseudocapacitive behavior with fast charge injection facilitated by an ultrathin dielectric h-BN. To address the MOF's low electronic conductivity, a 2D NiCo-MOF is grown on MXene nanosheets, enhancing conductivity and providing abundant redox-active sites. BN (boron nitride) serves a dual purpose, preventing restacking and facilitating charge injection toward NiCo-MOF. Synergistic contributions of 2D materials and a heterostructure with favorable charge injection dynamics among MOF, MXene, and BN contribute to enhanced electrochemical performance. Charge transfer mechanisms are elucidated using distribution of relaxation time technique to analyze complex EIS data and to differentiate electrode kinetics based on their respective relaxation time constants. An asymmetric supercapacitor, MOF-MXene-BN//activated carbon, achieves a specific capacity of 798 C/g, an energy density of 81 Wh/kg at 365 W/kg, and 81% capacitance retention over 5,000 cycles.

Reticular chemistry guided precise construction of zirconium-pentacarboxylate frameworks with 5-connected Zr6 clusters

Zirconium-based metal-organic frameworks (Zr-MOFs) have been extensively studied due to their very rich structural chemistry. The combination of nearly unlimited carboxylic acid-based linkers and Zr6 clusters with multiple connectivities has led to diverse structures and specific properties of resultant Zr-MOFs. Herein, we demonstrate the successful use of reticular chemistry to construct two novel Zr-MOFs, HIAM-4040 and HIAM-4040-OH, with zfu topology. Based on a thorough structural analysis of (4,4)-connected lvt-type Zr-tetracarboxylate frameworks and a judicious linker design, we have obtained the first example of a Zr-pentacarboxylate framework featuring unprecedented 5-connected organic linkers and 5-connected Zr6 clusters. Compared with HIAM-4040, a larger Stokes shift is achieved in HIAM-4040-OH via hydroxyl group induced excited-state intramolecular proton transfer (ESIPT). HIAM-4040-OH exhibits high chemical and thermal stability and is used for HClO detection in aqueous solution with excellent sensitivity and selectivity.

Isolation of a Cd-Based Coordination Polymer Containing Mixed Ligands: Time- and Temperature-Dependent Synthesis, Sulfonamide Antibiotics Detection, and Schottky Diode Fabrication

In this study, we present a new cadmium(II)-based two-dimensional coordination polymer [Cd (L)(NA)(H2O)] (L = Iminol form of N-nicotinoyl glycinate, NA = nicotinate), 1, containing two linkers generated from N-nicotinoyl glycine. A comprehensive investigation was carried out during the synthesis of the coordination polymers by varying the reaction time interval and temperature, and it revealed the formation of three distinct phases, of which two phases were previously reported and one was a new compound (1). The structure of compound 1 was determined by single-crystal X-ray diffraction, and it shows a corrugated layer structure with hydrogen bond interactions leading to three-dimensional supramolecular arrangements. Compound 1 exhibited strong emission at 420 nm when excited at 260 nm in an aqueous medium. The emission behavior of this compound was used for the detection of various sulfonamide antibiotics, sulfadiazine, sulfamethazine, sulfachloropyridazine, sulfameter, sulfaquinoxaline, and sulfathiazole, in the presence of common water pollutants. The luminescence quenching response of compound 1 to sulfonamide antibiotics was significant, ranging from 81 to 94%, and the detection sensitivity reached parts per billion (ppb) levels (226-726 ppb). Compound 1 also used for the fabrication of Schottky diode devices with a barrier height of 0.86 eV along with an excellent ideality factor of 1.24.

Highly selective detection of 2,4-dinitrophenol by fluorescent NH2-MIL-125(Ti) via dual-parameter sensing technology

The organic contaminant 2,4-dinitrophenol (2,4-DNP) is widely prevalent and poses significant risks to human health. Although numerous in-depth studies having been reported on the highly sensitive detection of 2,4-DNP, there are still challenges to its selective detection. Here, the fluorescence intensity ratio (I0/I) and emission peak shift (Δλ) were utilized for selective detection of 2,4-DNP by NH2-MIL-125(Ti). Notably, the emission peak of the NH2-MIL-125(Ti) suspension exhibited a remarkable red shift in the presence of 2,4-DNP (Δλ = 26 nm), accompanied by the blue shift or weak red shift of analogs, which provided a solid basis for selective detection of 2,4-DNP. Meanwhile, the I0/I ratio of the NH2-MIL-125(Ti) suspension exhibited a robust linear correlation with 2,4-DNP at the low concentration range (0-70 μM). The interaction of the analyte with NH2-MIL-125(Ti) was revealed to involve intermolecular charge transfer (ICT) and fluorescence resonance energy transfer (FRET) through XPS, FTIR, and UV-vis absorption spectroscopy. Additionally, we achieved the detection of 2,4-DNP using a smartphone by recognizing both the blue (B) values and the luminance (L) values. The obtained results demonstrated that the NH2-MIL-125(Ti) probe based on dual-parameter sensing technology exhibited excellent potential for selectively detecting 2,4-DNP in water environments, thereby offering significant prospects for its application in water quality assessment.

Multiresponsive luminescent sensors for antibiotics and CrVI with two luminescent ZnII/CdII coordination complexes

Two new ZnII/CdII luminescent coordination polymers (CPs) based on the V-shaped bis(imidazole) ligand 3,6-bis (1H-benzo[d]imidazol-1-yl)-9-methyl-9H-carbazole (bbimc) with [1,1'-biphenyl]-4,4'-dicarboxylic acid ligand (H2bpdc) have been synthesized under solvothermal conditions: {[Zn(bbimc)(bpdc)]·DMF·2.5H2O} (CP 1), {[Cd(bbimc)(bpdc)]·2DMF} (CP 2). CP 1 and CP 2 both display a uninodal 4-c unimodal sql topology 2D framework with vertex symbols of {44·62}. In addition, the two identical 2D nets of CP 2 were interpenetrated each other to form a 2D + 2D → 3D and generate a 2-fold interpenetrating architecture. Moreover, sensing investigations of CP 1 and CP 2 revealed that both of compounds can be used as a highly sensitive and selective multi-responsive luminescent sensor for sensing Cr2O72-, CrO42- and antibiotics (TC: Tetracycline; CTC: Chlortetracycline) in H2O by exhibiting fluorescence quenching with significant quenching constants (Ksv = 1.369 × 104 M-1 (Cr2O72-), 2.003 × 104 M-1 (CrO42-), 5.343 × 104 M-1 (TC), 8.706 × 104 M-1 (CTC) for CP 1 and 4.452 × 104 M-1 (Cr2O72-), 2.119 × 104 M-1 (CrO42-), 4.175 × 104 M-1 (TC), 1.257 × 105 M-1 (CTC) for CP 2). The detection limit are 0.67 μM (Cr2O72-), 0.48 μM (Cr2O72-), 0.23 μM (TC), 0.14 μM (CTC) for CP 1 and 0.28 μM (Cr2O72-), 0.54 μM (CrO42-), 0.31 μM (TC), 0.098 μM (CTC) for CP 2, respectively. In addition, the probable fluorescence quenching mechanism was studied through experiment and theoretical calculation and the co-existance of competitive absorption (CA) and photoinduced electron transfer (PET) progress contributed to such sensing processes.

Tetrahedral DNA nanostructure enhanced toehold-mediated strand displacement for highly sensitive electrochemiluminescence assay of CA125

Cancer antigen 125 (CA125) is a typical tumor marker of ovarian cancer. Here, a multi-amplified electrochemiluminescence (ECL) aptasensor was developed for efficient recognition of CA125 using tetrahedral DNA nanostructure (TDN) enhanced toehold-mediated strand displacement (TMSD) coupled with gold nanoparticles/Ru(bpy)32+/metal-organic framework (AuNPs/Ru/ZIF-MOF) signal probe. AuNPs and Ru(bpy)32+ modified ZIF-MOF acted as initial ECL signal and further used for the immobilization of TDN, the activated DNA templates on the surface of TDN were firstly hybridized with ferrocene labeled DNA probe (S6) and S5, in which, S6 acted as the energy acceptor of ECL signal from Ru(bpy)32+, making the sensor in a "signal-off" state. After the specific recognition of aptamer (AP) with CA125, DNA initiator (S7) was freed to induce the happen of TMSD by using S8 as the helper DNA, accompanying with the release of S6 from the electrode surface and the recovery of Ru(bpy)32+ ECL signal, making the sensor in a "signal-on" state. Then, S7 was recycled for the next TMSD, making the sensor highly sensitive with a detection limit of 6 × 10-3 pg/mL. Moreover, the proposed aptasensor achieved high performance for CA125 detection in human serum samples, illustrating the reliability of the sensor in clinical analysis.

Water-stable metal-organic frameworks (MOFs): rational construction and carbon dioxide capture

Metal-organic frameworks (MOFs) are considered to be a promising porous material due to their excellent porosity and chemical tailorability. However, due to the relatively weak strength of coordination bonds, the stability (e.g., water stability) of MOFs is usually poor, which severely inhibits their practical applications. To prepare water-stable MOFs, several important strategies such as increasing the bonding strength of building units and introducing hydrophobic units have been proposed, and many MOFs with excellent water stability have been prepared. Carbon dioxide not only causes a range of climate and health problems but also is a by-product of some important chemicals (e.g., natural gas). Due to their excellent adsorption performances, MOFs are considered as a promising adsorbent that can capture carbon dioxide efficiently and energetically, and many water-stable MOFs have been used to capture carbon dioxide in various scenarios, including flue gas decarbonization, direct air capture, and purified crude natural gas. In this review, we first introduce the design and synthesis of water-stable MOFs and then describe their applications in carbon dioxide capture, and finally provide some personal comments on the challenges facing these areas.

Multifunctional In-MOF and Its S-Scheme Heterojunction toward Pollutant Decontamination via Fluorescence Detection, Physical Adsorption, and Photocatalytic REDOX

A novel doubly interpenetrated indium-organic framework of 1 has been assembled by In3+ ions and highly conjugated biquinoline carboxylate-based bitopic connectors (H2L). The isolated 1 exhibits an anionic framework possessing channel-type apertures repleted with exposed quinoline N atoms and carboxyl O atoms. Owing to the unique architecture, 1 displays a durable photoluminescence effect and fluorescence quenching sensing toward CrO42-, Cr2O72-, and Cu2+ ions with reliable selectivity and anti-interference properties, fairly high detection sensitivity, and rather low detection limits. Ligand-to-ligand charge transition (LLCT) was identified as the essential cause of luminescence by modeling the ground state and excited states of 1 using DFT and TD-DFT. In addition, the negatively charged framework has the ability to rapidly capture single cationic MB, BR14, or BY24 and their mixture, including the talent to trap MB from the (MB + MO) system with high selectivity. Moreover, intrinsic light absorption capacity and band structure feature endow 1 with effective photocatalytic decomposition ability toward reactive dyes RR2 and RB13 under ultraviolet light. Notably, after further polishing the band structure state of 1 by constructing the S-scheme heterojunction of In2S3/1, highly efficient photocatalytic detoxification of Cr(VI) and degradation of reactive dyes have been fully achieved under visible light. This finding may open a new avenue for designing novel multifunctional MOF-based platforms to address some intractable environmental issues, i.e., detection of heavy metal ions, physical capture of pony-sized dyes, and photochemical decontamination of ultrastubborn reactive dyes and highly toxic Cr(VI) ions from water.

Ratiometric fluorescence sensing of hazardous ciprofloxacin based on aggregation induced emission enhancement of thiolate-protected gold nanoclusters induced by La3+ ion

In this research work, ultrasensitive and reliable ratiometric sensor was designed for assay of ciprofloxacin (CIPRO). The platform consists of thiolate-protected gold nanoclusters (GSH@AuNCs) with high fluorescence quantum yield and long-term stability. In the existence of lanthanum (La3+) ion, the GSH@AuNCs emission was sharply raised owing to the formation of La3+/GSH@AuNCs system accompanied with aggregation-induced emission enhancement (AIEE). Addition of CIPRO, a good La3+ ion coordinator, decreased the fluorescence emission of La3+/GSH@AuNCs system at 610 nm significantly as a result of disaggregation caused by the removal of La3+ ion from GSH@AuNCs surface. Furthermore, the blue emission of La3+-CIPRO coordination complex appears at 440 nm. Under optimized conditions, the fluorescence ratios (F440/F610) were linearly increased with increasing the CIPRO amount within the range of 0.003-200 µM with a limit of detection equal to 0.2 nM (S/N = 3). The as-fabricated La3+/GSH@AuNCs system possesses outstanding reliability and sensitivity for the detection of CIPRO. The system was effectively used to assay CIPRO in human urine and milk specimens with recoveries % of 97.6-102.3 % and 96.7-105.7 % for urine and milk samples, respectively and RSD % did not exceed 2.5 %, suggesting the accuracy of the method.

A Tb3+ ion encapsulated anionic indium-organic framework as logical probe for distinguishing quenching Fe3+ and Cu2+ ions

We successfully synthesized a stable anionic microporous metal-organic framework (MOF) HDU-1 ([Me2NH2]2In2[(TATAB)4(DMF)4](DMF)4(H2O)4) and constructed a fluorescent probe Tb@HDU-1 by an exchange strategy. Because of its suspension distinct fluorescent response of Tb(III) characteristic transition and ligand emission, the Tb@HDU-1 can be used as fluorescent probe for sensing towards Fe3+ and Cu2+ ions. It is surprising that Tb@HDU-1 is used as a ratiometric fluorescent probe for Cu2+ ions while only single peak detection for Fe3+ ions, which describes a particular rare example of a sensor based on Ln-MOFs to distinguish quenching Fe3+ and Cu2+ ions. Hence we designed a molecular logic gate device for making the distinction of Fe3+ and Cu2+ ions more clearly and appropriately. In addition, the different quenching effect between Fe3+ and Cu2+ ions may be ascribed to the differences of competitive absorption and interaction between frameworks and metal ions.

Preparation of fluorescent sensor based on Zn metal-organic framework for detection and determination of raloxifene as an anticancer drug

Breast cancer is the second leading cause of death for women worldwide. Raloxifene (RLX) is a somewhat effective drug in lowering cholesterol, preventing and treating invasive breast cancer in postmenopausal women with osteoporosis, and does not interfere with breast tissue. Nevertheless, considering the possibility of risk in biological function due to excessive use of anticancer drugs and the adverse effects of drugs in wastewater on plants, animals, and aquatic, it is useful to determine the concentration of RLX in water and human body fluids. Here, a fluorescent metal-organic framework (MOF) nanoparticle based on trinuclear zinc clusters called Zn-MOF was presented, which is a high-performance and fast-response fluorescent chemosensor that can be used to detect RLX based on the fluorescence quenching medium in water. FTIR, XRD, SEM, and EDS analyses were used to identify the functional group and determine the structure and morphology of Zn-MOF. pH range 3-10. The prepared nanoparticles showed symmetric emission with excitation at a wavelength of 310.0 nm. The performance of the proposed fluorescent nanosensor was proportional to the quenching of the fluorescent signal with increasing RLX concentration at 404.0 nm; the quenching fluorescence response was linear in RLX concentration from 0.7 to 350 ng/mL with a significant detection limit equal to 0.485 nM.

Novel Hydrophobic Functionalized UiO-66 Series: Synthesis, Characterization, and Evaluation of Their Structural and Physical-Chemical Properties

A novel set of four functionalized hydrophobic UiO-66-NHR series were synthesized through postsynthetic procedures, utilizing various benzoyl chlorides and UiO-66-NH2 as starting materials. This synthesis method was carried out by employing p- (1) and o-toluoyl (2), as well as 2- (3) and 4-fluorobenzoyl (4) substituents. The analysis of the resulting compounds was performed using conventional spectroscopic methods such as FT-IR and 1H NMR to quantify the conversion rate into amide. Furthermore, SEM and XPS techniques were employed for morphological and surface analysis. Finally, the evaluation of the chemical stability and contact angle using the sessile drop method was performed to evaluate the technological potential of these compounds for application in aqueous and acidic media (such as selective separation of different metals and wastewater recovery).

Truxene-to-Fluorenone Energy Transfer in a Robust Mesoporous Zn-MOF

A new metal-organic framework (MOF; [Zn4O(hett)4/3(fluo)1/2(bdc)1/2]n; TFT-MOF) constructed on chromophoric ligands 5,5',10,10',15,15'-hexaethyltruxene-2,7,12-triacetate (hett), 9-fluorenone-2,7-dicarboxylate (fluo), terephthalate (bdc), and the Zn4O node has been prepared and identified by powder X-ray diffraction. This luminescent MOF exhibits large mesoporous pores of 2.7 nm based on computer modeling using density functional theory (DFT) calculations. The steady-state and time-resolved fluorescence spectra and photophysical parameters of TFT-MOF have been investigated and compared with those of the free ligands and their basic chromophores. All in all, TFT-MOF exhibits particularly efficient singlet-singlet energy-transfer processes described as 1(hett)* → (fluo) and 1(bdc)* → (fluo), leading to fluorescence arising for the fluo lumophore operating only through Förster resonance energy transfer (FRET) with an efficiency of transfer of up to >95%. This experimental conclusion was corroborated by DFT and time-dependent DFT (TDDFT). For the 1(hett)* → (fluo) process, the approximated overall rate constant of energy transfer was evaluated to be at most 2.04 × 1010 s-1 (using a Stern-Volmer approach of solution data and the relationship between distance and concentration). This process was analyzed using the Förster theory, where two intrapore energy transfer paths of center-to-center distances of 13 and 25 Å have been identified. TFT-MOF photosensitizes the formation of singlet oxygen (1O2 (1Σg)) as detected by its phosphorescence signal at 1275 nm.

Pyridyl-Isonicotinoyl Hydrazone-Bridged Zn(II) Coordination Framework with Thiophenedicarboxylato Link: Structure, Biological Activity, and Electrical Conductivity

Multidimensional applicability of functional materials is one of the focal attractions in today's scientific research. Highly stable and crystalline coordination polymers served as one of the active members in the club of multifunctional materials. Toward this concept, a 3-dimensional (3D) coordination framework, {[Zn2(tdc)2(pcih)2]n} (1) (tdc2-, 2,5-thiophene dicarboxylate; pcih, pyridine-4-carboxaldehyde isonicotinoyl hydrazine), is designed and has been structurally well characterized by single crystal X-ray crystallography. One of the carboxylate groups of tdc2- chelates to Zn(II), while the other carboxylato group (-COO) acts as bridging-O to neighboring Zn(II); the pcih serves as pyridyl-N bridging motif to two Zn(II) centers. The optical band gap, 3.83 eV (Tauc's plot), implies probable semiconducting ability of the material. Interestingly, the device fabricated using compound 1 measures the electrical conductivity, 2.21 × 10-5 S cm-1, and series resistance (Rs), 807 Ω, at the dark phase, which are improved significantly to 6.36 × 10-5 S cm-1 and 460 Ω, respectively, under illumination conditions. Isoniazid, used to synthesize pcih and hence the Zn(II) compound 1, is a medicine; so, the medicinal efficiency of 1 is checked by measuring the anticancer activity against MDA-MB-231, HeLa, HCT-116, and HepG2 cells. It is observed that drug efficacy is highest on MDA-MB-231 cells (IC50: 19.43 ± 1.36 μM) than other cancer cells [IC50: 24.43 ± 2.02 μM (HeLa), 26.06 ± 3.48 μM (HCT-116), and 44.28 ± 3.04 μM (HepG2)]. Therefore, the material has significant contribution in the area of energy and health toward the sustainable development goals.

Selective and Rapid Detection of 4-Nitrophenol in River and Treated Industrial Wastewater by a Luminescent Lanthanide Metal-Organic Framework Sensor

Phenolic organic compounds are widely used industrial chemicals that exist extensively in the environment and have a significant impact on human health. 4-Nitrophenol (4-NP) is a typical phenolic organic compound found in aqueous environments. Efficient detection of 4-NP in wastewater is highly challenging due to the complexity of testing environmental samples. Herein, a luminescent lanthanide metal-organic framework (MOF) sensor based on the Eu3+ ion {[Eu(HL)(L)(H2O)]·2H2O}n (EuMOF; H2L = 5-(4H-1,2,4-triazol-4-yl)benzene-1,3-dicarboxylic acid) was successfully synthesized for efficient 4-NP detection in wastewater. Fluorescence sensing experiments revealed that 4-NP could greatly quench the EuMOF fluorescence. Subsequently, EuMOF was applied to 4-NP detection in distilled water, tap water, river water, and treated industrial wastewater, exhibiting high sensitivity, a fast response within 30 s, high selectivity, excellent reusability, and a low detection limit. Finally, the fluorescence quenching mechanism was explored and attributed to competitive absorption of irradiated light between 4-NP and the ligand.

Nanotechnology-assisted treatment of pharmaceuticals contaminated water

The presence of pharmaceutical compounds in wastewater due to an increase in industrialization and urbanization is a serious health concern. The demand for diverse types of pharmaceutical compounds is expected to grow as there is continuous improvement in the global human health standards. Discharge of domestic pharmaceutical personal care products and hospital waste has aggravated the burden on wastewater management. Further, the pharmaceutical water is toxic not only to the aquatic organism but also to terrestrial animals coming in contact directly or indirectly. The pharmaceutical wastes can be removed by adsorption and/or degradation approach. Nanoparticles (NPs), such as 2D layers materials, metal-organic frameworks (MOFs), and carbonaceous nanomaterials are proven to be more efficient for adsorption and/or degradation of pharmaceutical waste. In addition, inclusion of NPs to form various composites leads to improvement in the waste treatment efficacy to a greater extent. Overall, carbonaceous nanocomposites have advantage in the form of being produced from renewable resources and the nanocomposite material is biodegradable either completely or to a great extent. A comprehensive literature survey on the recent advancement of pharmaceutical wastewater is the focus of the present article.

Highly Stable Amide-Functionalized Zirconium-Organic Frameworks: Synthesis, Structure, and Methane Storage Capacity

With the development of crystalline porous materials toward methane storage, the stability issue of metal-organic framework (MOF) materials has caused great concern despite high working capacity. Considering the high stability of zirconium-based MOFs and effective functions of amide groups toward gas adsorption, herein, a series of UiO-66 type of Zr-MOFs, namely, Zr-fcu-H/F/CH3/OH, were successfully designed and synthesized by virtue of amide-functionalized dicarboxylate ligands bearing distinct side groups (i.e., -H, -F, -CH3, and -OH) and ZrCl4 in the presence of trifluoroacetic acid as the modulator. Single-crystal X-ray diffraction and topology analyses reveal that these compounds are archetypal fcu MOFs encompassing octahedral and tetrahedral cages, respectively. The N2 sorption isotherms and acid-base stability tests demonstrate that the materials possess not only relatively high surface areas, pore volumes, and appropriate pore sizes but also great hydrolytic stabilities ranging pH = 3-11. Furthermore, the volumetric methane storage working capacities of Zr-fcu-H, Zr-fcu-F, Zr-fcu-CH3, and Zr-fcu-OH at 298/273 K and 80 bar are 187/217, 175/193, 167/187, and 154/171 cm3 (STP) cm-3, respectively, which indicate that the zirconium-based crystalline porous materials are capable of storing relatively high amounts of methane.

Two Stable Bifunctional Zinc Metal-Organic Frameworks with Luminescence Detection of Antibiotics and Proton Conduction

Functionalized crystalline solids based on metal-organic frameworks (MOFs) enable efficient luminescence detection and high proton conductivity, making them crucial in the realms of environmental monitoring and clean energy. Here, two structurally and functionally distinct zinc-based MOFs, [Zn(TTDPa)(bodca)]·H2O (1) and [Zn(TTDPb)(bodca)]·H2O (2), were successfully designed and synthesized using 3,6-di(pyridin-4-yl)thieno[3,2-b]thiophene (TTDPa) and 2,5-di(pyridin-4-yl)thieno[3,2-b]thiophene (TTDPb) as ligands, in the presence of bicyclo[2.2.2]octane-1,4-dicarboxylic acid (H2bodca). Both 1 and 2 display a three-dimensional (3D) structure with 5-fold interpenetration, and notably, 2 forms a larger one-dimensional pore measuring 17.16 × 10.81 Å2 in size. Fluorescence experiments demonstrate that 1 and 2 can function as luminescent sensors for nitrofurantoin (NFT) and nitrofurazone (NFZ) with low detection limits, remarkable selectivity, and good recyclability. A comprehensive analysis was conducted to investigate the differing sensing effects of compounds 1 and 2 and to explore potential sensing mechanisms. Additionally, at 328 K and 98% relative humidity, 1 and 2 exhibit proton conductivity values of 2.13 × 10-3 and 4.91 × 10-3 S cm-1, respectively, making them suitable proton-conducting materials. Hence, the integration of luminescent sensing and proton conductivity in monophasic 3D Zn-MOFs holds significant potential for application in intelligent multitasking devices.

Stable Pyrene-Based Metal-Organic Framework for Cyclization of Propargylic Amines with CO2 and Detection of Antibiotics in Water

A pyrene-based metal-organic framework, Cd2(PTTB)(H2O)2 (WYU-11), was synthesized from the tetracarboxylic pyrene ligand H4PTTB (H4PTTB = 1,3,6,8-tetrakis(3-carboxyphenyl)pyrene) and Cd(NO3)2·4H2O. Powder X-ray diffraction analysis discloses that the framework is stable in acid, base, and various organic solvent environments. WYU-11 shows excellent catalytic performance on the cyclization reaction of propargylic amines with CO2 into 2-oxazolidinones under mild conditions (60 °C, atmospheric CO2). 1H NMR studies unveiled that WYU-11 and 1,1,3,3-tetramethylguanidine (TMG) can synergistically activate the propargylic amine substrate and promote the reaction. Importantly, WYU-11 represents a rare example of noble metal-free heterogeneous catalyst that can catalyze the cyclization of CO2 with propargylic amines. In addition, by virtue of the excellent water stability and luminescence properties, WYU-11 shows excellent detection performance for sulfathiazole (STZ) and ornidazole (ODZ) in water. Investigation reveals that the coexistence of photoinduced electron transfer and internal filtering effect could reasonably explain the luminescence quenching of WYU-11 by the antibiotics.

Formic Acid-Regulated Defect Engineering in Zr-Based Metal-Organic Frameworks toward Fluorescence Sensor for Sensitive Detection of Chlortetracycline

The elaborate defect-engineering of luminescent metal-organic frameworks (MOFs) allows them with enhanced sensing performance. A modulator-induced defect formation strategy is adopted in this paper, and the impact of the open-metal sites on sensing process is rationalized. It is demonstrated that the defect level can be tuned to a remarkable extent by controlling the amount of modulator. When a particular defect concentration is reached, the UiO-66-xFA can be acted as highly sensitive ratiometric fluorescence probes for chlortetracycline (CTE) determination with an ultralow detection limit of 9.9 nm. Furthermore, by virtue of the obvious variation in fluorescence chromaticity of probes from blue to yellow, a sensory hydrogels-based smartphone platform is proposed for visible quantitation of CTE by identifying the RGB values. A delicate device integrated with UV lamp and dark cavity has been developed for avoiding inconsistencies of ambient light and visual errors. Finally, the sensor obtains satisfactory results in the detection of actual seafood samples, with no significant differences from those of liquid chromatography-mass spectrometry. This approach anticipates a novel route to sensitize optical sensors through the design and synthesis of moderate defects in luminescent MOFs.

Photocatalytic hydrogel film assisted forward osmosis (PFO) for water treatment: Sustainable performance and contaminant control

The integration of catalytic oxidation with forward osmosis (FO) holds promising potential to address two crucial challenges encountered by FO: fouling and unsustainable performance, but suitable approaches are still rare. Herein, we have successfully developed a photocatalysis-assisted forward osmosis (PFO) system. In the PFO, a self-made porous carbon nitride doped functional carbon nanotube photocatalytic hydrogel film (PCN@CNTM) was engaged in the FO process in an inventive way by simply sticking to the commercial FO membrane surface, preventing damage to the membrane from the catalyst's direct insertion and delaying the assault from the oxidation groups. PFO allowed organic pollutants to decompose in the feed solution (90%) and on the membrane surface, regulating the water chemical potential and giving the FO membrane antifouling properties. This resulted in sustainable water flux (11.8 LMH) with no significant membrane fouling in PFO, whereas in FO alone there was a significant fouling and flux drop (from 12.73 to 7.23 LMH in 4 h). Moreover, the expensive FO membrane was protected while the hydrogel film can be replaced on demand. The PFO exemplifies the concept of synergistic technology integration, presenting a new perspective on harnessing the strengths of distinct technologies in a mutually beneficial manner.

Synthesis and Study of a Metal-Organic Framework-based Sulfite Fluorescence Sensor Modified with Urushiol

Sulfites can pollute the environment and pose a great risk to human health in daily life, so there is an urgent need to develop efficient and lightweight sulfite detection materials. In this study, metal-organic framework-5-NH2/urushiol/PVP nanofiber composite films were prepared by an electrospinning technique for the fluorescence detection of sulfites. The results showed that the composite film could resist sulfuric acid corrosion at a concentration of 80% and inactivate Escherichia coli and Staphylococcus aureus at a concentration of 99%, and its maximum tensile strength was increased from the initial 2.753 to 4.145 N. The composite film was sensitive and specific for the fluorescence detection of sulfite.