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Recently emerging perovskite nanocrystals (PNCs) have drawn considerable attention due to the superior optoelectronic performances. However, the terrible stability of red emissive PNCs (r‐PNCs) limits their broader application in aqueous media. Despite various encapsulation methods are proposed, the preparation of aqueous r‐PNCs with facile operation and excellent durability is still challenging. Herein, aqueous green emissive PNCs (g‐PNCs) by employing water as an external stimulus to treat oleyamine‐capped CsPbBr3 PNCs are synthesized initially, and then aqueous‐stable pure red emissive PNCs by anion‐exchange reaction and subsequently thiocyanate (SCN‐) passivation treatment (SCN‐r‐PNCs) are prepared. The obtained aqueous‐stable SCN‐r‐PNCs display high brightness, outstanding stability, and extended photoluminescence lifetime. Moreover, by combining aqueous r‐PNCs and portable smartphones, a fluorescence chemosensor for the detection of aqueous SCN− ions is constructed, which exhibits simple operation, high sensitivity, high selectivity, low detection limit, and visualized sensing. This work not only provides a new and facile strategy to prepare aqueous‐stable red emissive PNCs, but also further extends the application of red emissive PNCs in aqueous‐based fields. [ABSTRACT FROM AUTHOR]

Photoactivated dynamic ultralong room‐temperature phosphorescent (PAD‐URTP) materials with changing emission colors are attractive and meaningful but are rarely reported. Herein, a one‐pot heat treatment strategy for embedding 1‐hydroxy‐2‐naphthoic acid (1H2NA) and 2‐hydroxy‐1‐naphthoic acid (2H1NA) into boric acid (BA) matrix (named 1H2NA@BA and 2H1NA@BA) to construct PAD‐URTP materials is developed, which exhibits rapid and reversible photoactivated phosphorescence, as well as photo‐stimulated dynamic change of luminescence color. The luminescent color of 1H2NA@BA could continuously change from blue‐purple to bright cyan‐white upon prolonged 365 nm UV light irradiation, which is attributed to the combined effect of static blue fluorescence and dynamic photoactivated green phosphorescence. Significantly, it could emit over 10 s green afterglow after switching off the UV irradiation. The combination of experiment and theoretical calculation results reveal that their PAD‐URTP behavior is attributed to the energy accumulation of triplet states under UV light irradiation. Finally, a series of information encryption and a complete story of "a mouse and cake" are successfully fabricated by using 1H2NA@BA with other luminescence materials. Thus, this study demonstrates fast PAD‐URTP materials with dynamic color‐changing luminescence and opens up new possibilities as the photo‐responsive luminescent material for further mechanistic understanding and future application. [ABSTRACT FROM AUTHOR]

Organic radical luminescent materials have attracted worldwide attention because of their absolute spin‐allowed radiative transition and sensitivity to the environment, which give it multiple stimulus response properties. Nowadays, how to regulate and utilize the sensitivity of radicals has become a hot and difficult issue. Here, arylphosphonium bromide salts are introduced into the molecular backbone of naphthimide (NMI) using an intramolecular counterion strategy, and prepared a novel multifunctional stabilized radical luminescent: TPP‐o‐3OMe‐NMI‐Br. Interestingly, this molecule exhibits different assembly modes in different solvents, resulting in the generation of two crystals with different fluorescence (green: G‐C; orange–yellow: Y‐C), in which the Y‐C crystalline powder exhibits excellent stabilization properties for doublet and triplet excitons, which induce the emission of orange–yellow radical afterglow, and exhibits multi‐stimuli responsiveness to external pressure (P), temperature (T) and water (W). Moreover, interesting time‐dependent photoactivated colorful fluorescence and orange–yellow radical afterglow can be observed in TPP‐o‐3OMe‐NMI‐Br@PMMA films with different doping ratios and exhibit multi‐color tunability, multiple stimulus responses, multiple data encryption, and optical information erase/write behavior. This study not only broadens the types and applications of organic radical long afterglow materials but also provides new ideas for designing new organic "chameleon" luminescent materials in the field of smart luminescence materials. [ABSTRACT FROM AUTHOR]

Molecular profiling of protein markers on small extracellular vesicles (sEVs) is a promising strategy for the precise detection and classification of ovarian cancers. However, this strategy is challenging owing to the lack of simple and practical detection methods. In this work, using an aptamer‐based nanoflow cytometry (nFCM) detection strategy, a simple and rapid method for the molecular profiling of multiple protein markers on sEVs was developed. The protein markers can be easily labeled with aptamer probes and then rapidly profiled by nFCM. Seven cancer‐associated protein markers, including CA125, STIP1, CD24, EpCAM, EGFR, MUC1, and HER2, on plasma sEVs were profiled for the molecular detection and classification of ovarian cancers. Profiling these seven protein markers enabled the precise detection of ovarian cancer with a high accuracy of 94.2 %. In addition, combined with machine learning algorithms, such as linear discriminant analysis (LDA) and random forest (RF), the molecular classifications of ovarian cancer cell lines and subtypes were achieved with overall accuracies of 82.9 % and 55.4 %, respectively. Therefore, this simple, rapid, and non‐invasive method exhibited considerable potential for the auxiliary diagnosis and molecular classification of ovarian cancers in clinical practice. [ABSTRACT FROM AUTHOR]

Ischemic stroke is a disabling and fatal disease caused by the insufficient blood supply to the brain. Stellate ganglion block (SGB) is a type of anesthesia commonly used to relieve pain. Here, we sought to identify the effects of SGB on cerebral ischemia-reperfusion (I/R) injury. The middle cerebral artery occlusion (MCAO) model was established in rats. The brain injury was assessed using the 2,3,5-triphenyl-tetrazolium-chloride (TTC) staining assay and neurological score. Ferroptosis was analyzed by detecting cell death, Fe2+ content, glutathione (GSH), malonic dialdehyde (MDA), superoxide dismutase (SOD), and ferroptosis-related factors. The mechanisms of SGB were assessed using the western blot. The results showed that I/R increased brain infarction and damaged neurological function. SGB decreased I/R-induced infarction and improved neurological function. Meantime, SGB inhibited ferroptosis of the hippocampus induced by I/R via the Hippo pathway. and the Yes1 associated transcriptional regulator (YAP) of this pathway was positively correlated with the ferroptosis-related solute carrier family 7 member 11 (SLC7A11). Inhibition of the Hippo pathway reversed the effects of SGB on brain injury and ferroptosis. In conclusion, SGB inhibited ferroptosis of hippocampal neurons via activating the Hippo pathway and thereby alleviated I/R injury. The data provide a novel insight into the treatment of ischemic stroke and even other ischemic encephalopathies. [ABSTRACT FROM AUTHOR]

Iron (Fe3+) is an essential trace element in biological organisms. Abnormal concentrations of Fe3+ in aquatic possess the potential to disrupt normal physiological and metabolic processes in living organisms. Consequently, the pursuit of developing fluorescent probes for detecting Fe3+ concentrations in water samples is highly significant. The lone electron pair on the nitrogen atom of quinoline demonstrates outstanding coordination capabilities, enabling the selective detection of metal ions through coordination. Nevertheless, the interaction between metal ions and quinoline-based fluorescent probes tends to lead to nanoparticle aggregation, causing aggregation-caused quenching (ACQ) phenomena. This severely restricts the practical application of these probes. To address this challenge, the study utilizes quinoline as the foundational framework and modulates the excited-state electronic structure of quinoline derivatives through substituent effects. This facilitates the transition from ACQ to aggregation-induced emission (AIE). By integrating theoretical calculations, the paper proposes a comprehensive strategy for designing AIE molecules based on quinoline. This contribution provides innovative perspectives on AIE molecule design. Ultimately, the AIE property of the 8-MQB molecule is harnessed to develop a fluorescent probe capable of detecting Fe3+ in water samples. The fluorescence intensity exhibits a robust linear correlation with Fe3+ concentrations within the range of 5.0 μM to 0.3 mM. Moreover, the probe demonstrates exceptional resistance to interference from other metal ions. In conclusion, this research presents a universal strategy for designing AIE molecules and introduces an AIE probe for the rapid detection of Fe3+ concentrations in water samples. [Display omitted] • The modulation of quinoline derivatives' excited-state electronic structure via substituent effects shifts them from ACQ to AIE, enabling a novel Fe3+ AIE fluorescent probe. [ABSTRACT FROM AUTHOR]

Water constitutes the most prevalent impurity in organic solvents, exerting significant influence on chemical reactions and potentially leading to fires and explosions, even in minute quantities. Thus, the development of convenient, rapid, and cost effective fluorescent probes for real-time monitoring of water content in organic solvents is imperative. Although some fluorescent materials have been synthesized for this purpose, most suffer from laborious preparation processes and poor cycling performance, constraining their practical application. This study investigates the impact of hydrogen bonding on the aggregation-induced emission (AIE) properties of quinoline derivatives, leveraging quinoline as the foundational scaffold and its nitrogen atom as the hydrogen bond acceptor. Research findings elucidate that intermolecular hydrogen bonding of quinoline is the primary determinant of their AIE behaviors. By harnessing the phenomenon of water molecules forming intermolecular hydrogen bonds with quinoline nitrogen atoms, we devised a straightforward and rapid method to fabricate a fluorescent test paper for real-time monitoring of water content in organic solvents. Experimental results demonstrate that even minute changes in water content, down to concentrations as low as 0.5 % by volume in organic solvents, can induce fluorescence changes in the test paper, which also exhibits favorable cycling performance. This study not only explores the influence of hydrogen bonds on the AIE properties of quinoline derivatives but also pioneers the development of a cost-effective, rapid, and recyclable test paper for real-time monitoring of water content fluctuations in organic solvents. [Display omitted] • By regulating intermolecular hydrogen bonds, the transformation of quinoline derivatives from ACQ to AIE is achieved. • The hydrogen bonding strategy is further employed to design fluorescent test paper capable of real-time detection of trace water concentration fluctuations in organic solvents. [ABSTRACT FROM AUTHOR]

Transmission electron microscopy (TEM) is one of the most important methods for the morphological characterization and structure analysis of nanomaterials. However, the characterization of magnetic materials has always been a challenge due to limitations arising from the design of electron microscopes. To tackle this problem, advanced sample preparation technology is needed, especially for magnetic materials. Here in this work ultrathin sectioning technology (ultramicrotomy) is used for the sample preparation of magnetic Fe 3 O 4 nanoparticles embedded into a resin, where the loaded resin can be sliced into nanoscale sheets. By the optimization of the embedding method and the slicing process, nano-sheets with uniform thickness and exceptional flatness were prepared, where the nanoparticles exhibited uniform dispersion. It is shown that this technology also helps reducing the degree of pollution of the electron microscope by the magnetic nanoparticles under different electron beam irradiation intensities. Generally, the magnetic nanoparticles are more resistant to electron beam bombardment when embedded into a resin. [ABSTRACT FROM AUTHOR]

2D (two-dimensional) covalent organic frameworks (COFs) have recently emerged as versatile photoactive functional materials. Herein, three β-ketoenamine linked 2D COFs were assembled with 2,4,6-triformylphloroglucinol (Tp) and 4,7-bis(4-aminophenyl)-2,1,3-benzothiadiazole (BTD) as the building blocks at 150, 120, and 25 ℃ respectively, leading to Tp-BTD-150, Tp-BTD-120, and Tp-BTD-25. In particular, the facile synthesis at 25 ℃ afforded Tp-BTD-25 that featured superior activity for the photocatalytic selective aerobic oxidation of benzylamine to the other two assembled at higher temperatures. Most importantly, both the stability and activity of Tp-BTD-25 photocatalyst were augmented with exogenous 5 mol% TEMPO (2,2,6,6-tetramethylpiperidine- N -oxyl) to ease the transfer of electrons and protons during the oxidation of benzyl amines. Preeminently, the selective aerobic oxidation of benzyl amines into imines was established by cooperative photocatalysis of Tp-BTD-25 with TEMPO irradiated by blue LEDs (light-emitting diodes). This work underscores that crystalline 2D COFs via facile synthesis can cooperatively work with a redox mediator to steer photocatalytic selective reactions. [Display omitted] • Three β-ketoenamine linked 2D COFs are assembled with Tp and BTD as the building blocks. • The interlayer stackings of the 2D COFs depend on the temperatures of synthesis. • The room-temperature synthesized Tp-BTD-25 features significantly superior photocatalytic activity. • Cooperative photocatalysis is constructed by introducing 5 mol% of TEMPO. • Selective aerobic oxidation of amines is accomplished by cooperative photocatalysis of Tp-BTD-25 with TEMPO. [ABSTRACT FROM AUTHOR]

The development of analytical method for selective and sensitive detection of gossypol (Gsp), an extraction from the cotton plants, is important but still challenging in food safety and medical field. Herein, we reported a turn-on near infrared (NIR) fluorescence detection strategy for Gsp based on a metal-organic framework (MOF), QBA-Yb, which was prepared from 4,4'-(quinolone-5, 8-diyl) benzoate with Yb(NO 3) 3 ·5H 2 O by solvothermal synthesis. The Gsp acted as another "antenna" to sensitize the luminescence of Yb3+, leading to the turn-on NIR emission upon 467 nm excitation. As Gsp concentration increased, the NIR emission at 973 nm enhanced gradually, thus enabling highly sensitive Gsp detection in a turn-on way. The experiment and theoretical calculation results revealed the presence of strong hydrogen bonds between Gsp molecules and the MOF skeleton. The developed QBA-Yb probe showed excellent characteristics for detection of Gsp molecules, accompanied by wide linear range (5–160 μg/mL), low detection limit (0.65 μg/mL) and short response time (within 10 min). We have further demonstrated that the QBA-Yb probe was successfully applied for the determination of Gsp in real samples of cottonseeds. [Display omitted] • A turn-onsensing platform was constructed based on QBA-Yb for precisely evaluating gossypol content in cottonseed sample. • The turn-onfluorescence sensing mode improves the detection sensitivity and anti-interference ability. • QBA-Yb could achieve excellent detection of gossypol with a rapid response and low detection limit in the near-infrared range. [ABSTRACT FROM AUTHOR]

To obtain an electrochemical sensor with high sensitivity and good selectivity for determination of podophyllotoxin (PPT), a kind of graphene composite (rGO@TiO 2) with multi-layer structure and excellent conductivity was prepared by hydrothermal treatment of reduced graphene oxide (rGO) and TiO 2 nanoparticles. The composite was characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and a sensor using rGO@TiO 2 as a signal amplification element was fabricated by in-situ polymerization of PPT imprinted membrane (PPT-MIM) on the rGO@TiO 2 modified glassy carbon electrode (PPT-MIM/rGO@TiO 2 /GCE). The structure and electrochemical performance of PPT-MIM/rGO@TiO 2 /GCE as well as the mechanism with superior conductivity of rGO@TiO 2 exceeding the ones of the mixture of TiO 2 and rGO (TiO 2 -rGO) or the pure TiO 2 and rGO were explained with different technologies. Under the optimal conditions, the present sensor showed a linear response for the determination of PPT by differential pulse voltammetry (DPV) in the range of 1.0 × 10−9 − 1.0 × 10−7 mol L−1 (R2 = 0.9980) and 1.0 × 10−7 − 3.0 × 10−4 mol L−1 (R2 = 0.9991) with the limit of quantification is 1.0 × 10−9 mol L−1 and the limit of detection of 3.0 × 10−10 mol L−1. The sensor not only possesses high sensitivity and good selectivity, but also exhibits excellent repeatability and stability. It has been used to detect PPT in real samples (including Podophyllum hexandrum , human urine and human whole blood) with satisfied recoveries of 92.0%–102.3%. Unlabelled Image • Nanocomposites (rGO@TiO 2) prepared with hydrothermal possesses excellent conductivity. • rGO@TiO 2 is introduced as a signal amplification element. • PPT-MIM obtained by in-situ polymerization is used as specific recognition material. • The resulting PPT-MIM/rGO@TiO 2 /GCE shows high sensitivity and excellent selectivity. [ABSTRACT FROM AUTHOR]

The YNU-1 nanobelts possessing abundant free carboxyl groups was applied for wastewater treatment of Fe3+, which exhibited highest adsorption capacity of 456.37 mg/g among all previous adsorbents. • Most adsorbents own poor adsorption performance due to the less binding sites. • 2D MOFs possess more unsaturated coordination centers and accessible active sites. • YNU-1 nanobelts can be obtained facilely by immersing YNU-1 crystals in water. • YNU-1 nanobelts showed an excellent adsorption performance for Fe3+. Ultrathin metal-organic frameworks (MOFs) have emerged as a novel class of two-dimensional materials for their unique properties, such as the larger surface area, enriched unsaturated coordination centers and more accessible active sites, which are beneficial for improving their performances in catalysis, sensing and separation. In this work, the MOF (named YNU-1 nanobelts) was exploited to selectively remove Fe3+ from aqueous solutions, which showed an excellent adsorption performance with the adsorption capacity of 456.37 mg/g. The value is the highest among all reported adsorbents of Fe3+, owing to the coordination between the Fe3+ and abundant carboxyl groups on the surface of YNU-1 nanobelts. The adsorption behavior can be well-described with a pseudo-second-order kinetic model, which revealed a chemisorption process. The α-Fe 2 O 3 on the surface of YNU-1 nanobelts after adsorption was confirmed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and element mapping measurements. The YNU-1 nanobelts was successfully applied for iron treatment in real sample. Our study provided a facile and efficient method for the removal of iron ions from water. [ABSTRACT FROM AUTHOR]

• The pure E/Z isomers isoniazid-substituted TPE derivatives was confirmed by single crystal, mass spectrometry and NMR spectroscopy. • The structure-property relationships of these molecules have been systematically investigated. • The E/Z isomers possessed dramatic differences in fluorescent properties and distinct aggregate self-assembly morphologies. • Isomers exhibited diverse changes in response to stimuli. • Isomers can be used as efficient fluorescent probes for the detection of copper in the environment. Stereoisomers play an irreplaceable prominent role in life sciences. In molecular engineering, the isomers have been continuously designed and synthesized, and their interrelationships among structure-property-function have also been explored. However, the difficulties in purification and structural confirmation of tetraphenylethene (TPE) derivatives' stereoisomers hinder their structural diversity and scope of functions. Meanwhile, there were few researches on the macroscopic optical differences about TPE derivatives isomers. Herein, isoniazid-substituted TPE derivatives stereoisomers have been synthesized, as confirmed by single crystal data, mass spectrometry and NMR spectroscopy. The different photophysical properties were caused by the introduction of functional group isoniazid on the periphery of TPE. These isomers possessed dramatic differences in fluorescent properties, and exhibited diverse changes in response to stimuli. They also have distinct aggregated self-assembly morphologies because of different intermolecular hydrogen bonding, and they can be used as efficient fluorescent probes for detecting copper. Based on the coordination-driven sensing system, the morphologies of isomers aggregates changed significantly after interaction with copper, and the stoichiometry between them is 2:1. The theoretical calculation demonstrated that they have obvious intramolecular charge transfer behavior. Our research provided a good strategy for designing different substituted groups that can produce various functions and have more potential applications. [ABSTRACT FROM AUTHOR]

A HDBB@ZIF-8 fluorescent probe has been developed by encapsulating the aggregation-induced emission (AIE) molecule 4,4'-(hydrazine-1,2-diylidenebis(methanylylidene)) bis(3-hydroxybenzoic acid) (HDBB) into the nanochannels of zeolitic imidazolate frameworks-8 (ZIF-8) for distinguishing small alcohol solvent molecules. The crystal structure and morphology of ZIF-8 are well maintained after the encapsulation of HDBB molecules. Encapsulation of HDBB into the confined nanospace of ZIF-8 not only triggered new green fluorescent emission but also endowed them with unique carbon chain length-dependent fluorescence intensity for alcohols, which has not been observed in pure HDBB and ZIF-8. This property could be attributed to the alcohol–water sorption selectivity of host ZIF-8. Moreover, a linear relationship is obtained between the fluorescent intensity of these composites and the concentrations of ethanol with a wide linear range, which could be employed as a chemosensor to detect the content of ethanol in the real wine sample. Image 1 [ABSTRACT FROM AUTHOR]