Construction of a Sensitive Fluorescence Sensor for Convenient 1‑HP and UA Detection Relied on a Stable Eu-MOF

Herein, a new three-dimensional Eu-MOF, [Me2NH2]2­[Eu3(mtptc)2­(CH3COO)3]·DMA·H2O (1), has been elaborately prepared through the reaction of europium nitrate and a symmetric tetra-carboxylate ligand, 5′-methyl-[1,1′:3′,1″-triphenyl]-3,3″,5,5″-tetracarboxylic acid (H4mtptc). Noteworthily, compound 1 represents marked stability covering acid–base stability in the pH range of 2–14, thermal stability maintaining skeleton integrity when heated at 350 °C, solvent stability in some common solvents, and air stability in open air more than 4 weeks characterized by powder X-ray diffraction (XRD) and temperature-dependent powder XRD analyses. Remarkably, luminescent sensing measurements manifest that compound 1 is deemed as a hopeful fluorescent probe for rapid recognition of 1-hydroxypyrene (1-HP) and uric acid (UA) equipped with excellent sensitivity with a quenching efficiency of 99.1% for 1-HP and 97.4% for UA. Besides, the luminescent sensing performance of compound 1 toward 1-HP and UA possesses super stability in dimethylformamide/H2O solution, N-(2-hydroxyethyl)piperazine-N′-ethanesulfonic acid buffer solution, and human urine

Notably Stable Bifunctional Europium-Centered Metal–Organic Framework for Instant Sensing of Uric Acid and 1‑Hydroxypyrene in Human Urine

A new Eu-centered metal–organic framework, [(CH3)2NH2]­[Eu­(cdip)­(H2O)] (compound 1), was fabricated by the reaction of Eu­(NO3)3·6H2O and a high-symmetry ligand, 5,5′-carbonyldiisophthalic acid (H4cdip). Interestingly, compound 1 exhibits extraordinary stability, including air, thermal, and chemical stabilities, in an aqueous solution with a broad pH range of 1–14, which is rarely seen in the field of metal–organic framework materials. Notably, compound 1 is proved to be an exceptional prospective luminescent sensor for recognizing 1-hydroxypyrene and uric acid both in DMF/H2O solution and human urine with a fast response (1-HP: 10 s; UA: 80 s), high quenching efficiency Ksv (7.01 × 104 M–1 for 1-HP and 5.46 × 104 M–1 for UA in DMF/H2O solution; 2.10 × 104 M–1 for 1-HP and 3.43 × 104 M–1 for UA in human urine), low limit of detection (1.61 μM for 1-HP and 0.54 μM for UA in DMF/H2O solution; 0.71 μM for 1-HP and 0.58 μM for UA in human urine), and remarkable anti-interference ability based on luminescence-quenching effects observable by the naked eye. This work provides a new strategy for the exploration of potential luminescent sensors based on Ln-MOFs for 1-HP, UA, or other biomarkers in biomedical and biological fields

Automated lightweight model for asthma detection using respiratory and cough sound signals

Background and objective: Chronic respiratory diseases, such as asthma and COPD, pose significant challenges to human health and global healthcare systems. This pioneering study utilises AI analysis and modelling of cough and respiratory sound signals to classify and differentiate between asthma, COPD, and healthy subjects. The aim is to develop an AI-based diagnostic system capable of accurately distinguishing these conditions, thereby enhancing early detection and clinical management. Our study, therefore, presents the first AI system that leverages dual acoustic signals to enhance the diagnostic ACC of asthma using automated, lightweight deep learning models. Methods: To build an automated, lightweight model for asthma detection, tested separately with respiratory and cough sounds to assess their suitability for detecting asthma and COPD, the proposed AI models integrate the following ML algorithms: RF, SVM, DT, NN, and KNN, with an overall aim to demonstrate the efficacy of the proposed method for future clinical use. Model training and validation were performed using 5-fold cross-validation, wherein the dataset was randomly divided into five folds and the models were trained and tested iteratively to ensure robust performance. We evaluated the model outcomes with several performance metrics: ACC, precision, recall, F1 score, and area under the AUC. Additionally, a majority voting ensemble technique was employed to aggregate the predictions of the various classifiers for improved diagnostic reliability. We applied Gabor time–frequency transformation for feature extraction and NCA) for feature selection to optimise predictive accuracy. Independent comparative experiments were conducted, where cough-sound subsets were used to evaluate asthma detection capabilities, and respiratory-sound subsets were used to evaluate COPD detection capabilities, allowing for targeted model assessment. Results: The proposed ensemble approach, facilitated by a majority voting approach for model efficacy evaluation, achieved acceptable ACC values of 94.05% and 83.31% for differentiating between asthma and normal cases utilising separate respiratory sounds and cough sounds, respectively. The results highlight a substantial benefit in integrating multiple classifier models and sound modalities while demonstrating an unprecedented level of ACC and robustness for future diagnostic predictions of the disease. Conclusions: The present study sets a new benchmark in AI-based detection of respiratory diseases by integrating cough and respiratory sound signals for future diagnostics. The successful implementation of a dual-sound analysis approach promises advancements in the early detection and management of asthma and COPD.We conclude that the proposed model holds strong potential to transform asthma diagnostic practices and support clinicians in their respiratory healthcare practices.</p

Tuning Topology of Two-Dimensional Trifluoromethyl-Functionalized Covalent Organic Framework for Efficient Separation of Isomers

The advantages of designability, functionalizability, and tailorability makes covalent organic frameworks (COFs) promising for separation application. Here, we propose a strategy to improve the performance of gas chromatography for the separation of isomers by tuning the topology of two-dimensional (2D) COFs. 2,5-Diaminobenzotrifluoride (Pa-CF3) with trifluoromethyl functional group was selected to condense with biphenyl-3,3′,5,5′-tetracarbaldehyde (BTA) possessing D2h symmetry, and 1,3,5-benzenetricarboxaldehyde (Tb) possessing C3 symmetry, respectively, to prepare heteropore BTAPa-CF3 and homopore TbPa-CF3. The prepared BTAPa-CF3 has a richer pore structure and higher density of the trifluoromethyl functional group than TbPa-CF3. The abundant pore sizes of the heteropore structure and dipole forces of the trifluoromethyl functional group gave the BTAPa-CF3 bonded capillary column better performance than the TbPa-CF3 bonded capillary column for the separation of hexane, heptane, xylene, chlorotoluene, butylbenzene, and isoamyl acetate isomers with good repeatability. This work provides new idea for designing stationary phases for the separation of isomers from a topological view

Quantitative Relation between Ionic Diffusivity and Ionic Association in Ionic Liquid–Water Mixtures

Molecular dynamic simulations of aqueous mixtures of imidazolium ionic liquids (ILs) were performed to elucidate the dependence of the ionic diffusivity on the microscopic structures changed by water. Two distinct regimes of the average ionic diffusivity (Dave) were identified with the increased water concentrations: the jam regime with slowly increased Dave and the exponential regime with rapidly increased Dave, which are found to be directly correlated to the ionic association. Further analysis leads to two general relationships independent of IL species between Dave and the degree of ionic association: (i) a consistent linear relationship between Dave and the inverse of ion-pair lifetimes (1/τIP) in the two regimes and (ii) an exponential relationship between normalized diffusivities (D̃ave) and short-ranged interactions between cations and anions (Ẽions), with different interdependent strengths in the two regimes. These findings revealed and quantified the direct correlation between dynamic properties and ionic association in IL–water mixtures

Quantitative Relation between Ionic Diffusivity and Ionic Association in Ionic Liquid–Water Mixtures

Molecular dynamic simulations of aqueous mixtures of imidazolium ionic liquids (ILs) were performed to elucidate the dependence of the ionic diffusivity on the microscopic structures changed by water. Two distinct regimes of the average ionic diffusivity (Dave) were identified with the increased water concentrations: the jam regime with slowly increased Dave and the exponential regime with rapidly increased Dave, which are found to be directly correlated to the ionic association. Further analysis leads to two general relationships independent of IL species between Dave and the degree of ionic association: (i) a consistent linear relationship between Dave and the inverse of ion-pair lifetimes (1/τIP) in the two regimes and (ii) an exponential relationship between normalized diffusivities (D̃ave) and short-ranged interactions between cations and anions (Ẽions), with different interdependent strengths in the two regimes. These findings revealed and quantified the direct correlation between dynamic properties and ionic association in IL–water mixtures

Facile and Ultrasensitive Food Allergen Quantification Using Microzone Paper-Based Mass Spectrometric Immunoassay

Highly sensitive and rapid measurement of food allergens is essential to avoid unanticipated food allergies and to determine whether cross-contamination occurs in the food industry. Commercial immunoassay kits offer high specificity and convenience for allergen detection but still suffer limited quantitative sensitivity, accuracy, and stability based on the optical readout. In this work, a paper-based mass spectrometric immunoassay platform was constructed to achieve facile and highly sensitive quantification of peanut allergen, which combined the advantages of good specificity and accurate quantification from mass spectrometry and simplicity from a paper-based immunoassay. In this platform, a novel quaternary ammonium-based mass tag and a paper chip with a microzone were designed and developed, contributing to a large signal enhancement. This method was able to detect Ara h1 with a linear range of 0.1–100 ng mL–1 and a detection limit of 0.08 ng mL–1 in milk matrices. It has also been successfully applied to the accurate quantification of Ara h1 in six milk-related beverages, two biscuits, and two candy bars with complicated matrices and presented a low-concentration quantitation capability. This method gives a new type of mass spectrometric immunoassay for rapid and ultrasensitive allergen regulation in the food industry and for individual allergen differentiation research

Fabrication of a Stable Europium-Based Luminescent Sensor for Fast Detection of Urinary 1‑Hydroxypyrene Constructed from a Tetracarboxylate Ligand

A novel europium-centered metal–organic framework fabricated from a symmetric and rigid ligand with tetracarboxylate groups, 2,6-di­(2′,5′-dicarboxylphenyl)­pyridine (H4ddpp), has been synthesized solvothermally. Characterized by single-crystal X-ray diffraction, compound 1 features a 3D microporous structure with a butterfly-shaped trinuclear Eu3(COO)6 secondary building unit. Interestingly, three kinds of 1D open channels viewed in different directions in compound 1 are discovered, and the void ratio is calculated to be 47.5% by PLATON software. Solid-state luminescent experiments at 298 K reveal that compound 1 displays naked-eye characteristic red emission of Eu3+ ions monitoring the typical 5D0 → 7F2 transition. The exploration of luminescent sensing tests discloses that compound 1 has an outstanding capacity for recognizing urinary 1-hydroxypyrene (1-HP) with a quite fast response and high sensitivity, giving the quenching efficiency of 98.2% after the immersion time for just 1 min and 73.2% with the amount of 1-HP only 0.05 mg/mL. To our knowledge, it is the first reported Eu-MOF as an extremely fast-responsive and highly sensitive luminescent sensor for 1-HP which is interference-free from other urinary components. Furthermore, the successful preparation of the luminescent test papers makes compound 1 convenient, easy, and real-time in the application for sensing 1-HP in biomedical and biological fields