In this study, three molecular fluorescent probes (NIA-1, NIA-2, and NIA-3) were developed using naphthalimide as the fluorophore, combined with hydroxyl-, benzothiazole-, and benzimidazole-based recognition groups, respectively. The pKa values of these probes were determined to be 5.30, 4.90, and 7.70, and each exhibited a strong linear fluorescence response within specific pH ranges. Within narrow pH intervals, all three probes displayed a pronounced and reversible shift in their maximum fluorescence emission wavelengths, although their overall spectral profiles remained similar before and after protonation/deprotonation. Among the three, NIA-2 exhibited the narrowest pH-responsive range, spanning only 0.30 pH units. Distinct fluorescence color changes in the probe solutions were readily observed during acid-base transitions. Furthermore, these probes demonstrated strong potential for intracellular pH sensing and could be adapted into pH test papers for convenient and visual pH determination.

Primary amines are widespread in chemical and biological systems and are key indicators of food spoilage and environmental contamination. The rapid and accurate detection of these species is therefore of significant interest. We report a fluorescent probe (DCA) based on a coumarin scaffold that operates through a new diketone-amide transformation. Upon exposure to primary amine vapors, the diketone unit is rapidly converted to an amide Among the tested materials, the test-paper-loaded probe exhibits the most pronounced fluorescence blue-shift (from 559 to 483 nm), while the PVDF-immobilized probe achieves the shortest response time, down to 15 s. The proposed reaction mechanism was further validated by HPLC analysis along with two control experiments. The DCA probe demonstrates excellent selectivity for primary amines, high sensitivity, and robust stability. Furthermore, immobilization on diverse substrates, including test paper, PVA hydrogel, and PVDF, enables the fabrication of solid-state sensors that exhibit strong responses. This study introduces a new molecular strategy for ultrafast fluorescent sensing of primary amines with promising potential for practical applications.

The proliferation of counterfeit products poses significant challenges to modern society and economic development. Fluorescent anticounterfeiting technology has attracted much attention for its advantages including simple operation, low requirements for large-scale equipment, and strong recognition capabilities. Anti-counterfeiting strategies based on static fluorescent patterns could be easily imitated by counterfeiters. Therefore, the development of new dynamic fluorescent anti-counterfeiting strategy is an attractive and challenging research topic. This study reports a fast dynamic dual-stage fluorescent anti-counterfeiting technologies through combining different acid-base responsive luminophores. As a key component, compound DEAPAN-IM had imine and diethyl amino groups, which could exhibit fast dual-stage acid-base stimuli fluorescent changing properties. During the initial acid-base treatment, the compound exhibited a non-reproducible “quenching and emitting” fluorescence changing mode in seconds; in subsequent acid-base treatments, it exhibited a fast and reproducible “color-changing and recovery” fluorescence changing mode. This unique characteristic makes it very difficult to be imitated or misused by counterfeiters. Based on the fluorescence titration curves and proton NMR spectra analysis, a three-step acid-base responsive fluorescent changing processes was proposed for DEAPAN-IM. As a contrast, the other compounds DEAPAN-CHO and DPAPAN-IM could only show a mono “color-changing and recovery” fluorescent switching mode. Through the combination of compounds DEAPAN-CHO and DEAPAN-IM, a series of acid-base responsive color-changing patterns were prepared, and a fast dynamic dual-stage fluorescent anti-counterfeiting and information encryption strategy was achieved.

ABSTRACT The integration of two‐photon excited fluorescence and x‐ray scintillation into a single material entity is highly desirable for advanced multiscale medical and photonic applications. However, due to the lack of multiscale energy absorption capabilities or the uncontrollability of emission pathways, conventional luminescent materials are typically restricted to a single excitation modality. In this work, a series of luminescent color‐tunable lanthanide metal–organic frameworks (Ln‐MOFs) are synthesized by varying ratios of Ln 3+ ions with multimodal responsiveness. The strong x‐ray attenuation of heavy lanthanide centers and the large two‐photon absorption cross‐section of the NTB 3− ligands (H 3 NTB = 4,4',4''‐nitrilotribenzoic acid) synergistically enable across‐scale energy harvesting. Crucially, the suitably matched triplet state of the H 3 NTB ligand acts as a universal bridge, successfully converging the distinct initial excitations (one‐photon, two‐photon, and x‐ray) into an identical energy transfer pathway to produce highly efficient lanthanide‐centered emissions. Driven by these highly efficient emissions, the fabricated NTB‐Tb‐screen and NTB‐Eu‐screen films deliver exceptional x‐ray imaging spatial resolutions of 19.7 and 7.4 lp/mm, respectively.

A series of fluorescent dyes CH-OM, CH-MP, and CH-CN were synthesized by combining hydrazide-hydrazone with coumarin. These dyes exhibited reversible mechanochromic behaviours: solid-state fluorescence red-shifted under mechanical pressure and reverted to the original state after solvent vapor fuming, with the process being repeatable over multiple cycles. Based on this reversible response, a type of fluorescent inkless rewritable paper was successfully fabricated. Moreover, CH-MP demonstrated excellent lysosome-targeting ability in cellular environments. This study not only expanded the functional scope of small-molecule fluorescent dyes based on the hydrazide-hydrazone system but also broadened their potential for multidimensional applications.

Aqueous zinc ion batteries (ZIBs) coupling with Zn anodes and V-based cathodes are plagued by unfavorable side reactions at the Zn anode and irreversible structural degradation at the cathode. Herein, we introduce a multifunctional additive tetraethylene glycol (TG) into a cost-effective ZnSO4 system to stabilize both electrode/electrolyte interfaces. At the anode, the zincophilic and hydrophilic nature of TG reconstructs the solvation structure and creates a water-lean inner Helmholtz plane (IHP), and its high electron affinity triggers its preferential decomposition, facilitating a ZnCO3/ZnS bilayer solid electrolyte interphase (SEI). Together with the (101)-textured Zn deposition, this synergistic effect efficiently suppresses side reactions while accelerating ionic transport kinetics, leading to a dendrite-free Zn anode. At the cathode, TG anchors the VO framework, effectively inhibiting cathode dissolution. Consequently, Zn//Zn symmetric cells achieve an ultra-long lifespan exceeding 5150 h at 3 mA cm-2 and 1.5 mAh cm-2, and maintain stability for 160 h even at a high depth-of-discharge (DOD) of 40 %. Furthermore, Zn//V-EG (ethylene glycol (EG) preinserted V2O5) full cells deliver remarkable cycling stability of 5700 cycles at 5 A g-1. This work breaks the conventional trade-off between electrolyte conductivity and interfacial stability, paving the way for high-performance and cost-effective ZIBs.

Precise visualization of peroxynitrite (ONOO-) in living systems remains challenging due to its transient nature and the need for deep-tissue optical penetration. Here, we report XH-ONOO, a near-infrared fluorescent probe engineered with a donor-pi-acceptor-pi-donor (D-pi-A-pi-D) scaffold formed by coupling an electron-rich coumarin unit with a beta-diketonate-BF2 acceptor. Quantum-chemical analysis elucidates its optimized conjugation and charge-transfer characteristics. XH-ONOO exhibits an ultrafast and highly selective response to ONOO- , producing a >250 nm emission shift, which minimizes spectral crosstalk between the probe and its reaction product. Notably, the probe supports efficient two-photon excitation (740 nm), enabling high-contrast imaging of both exogenous and endogenous ONOO- in live cells. Furthermore, XH-ONOO achieves tissue, high-resolution ONOO- imaging in a mouse model, establishing its utility as a sensitive and versatile tool for tracking oxidativeinflammatory signaling in complex biological environments.

Fluorescent molecules with a D-pi-A structure based on intramolecular charge transfer have been widely investigated. In this work, we designed two D-pi-A-pi-D fluorescent molecules, XH-1 and XH-2, using a coumarin-BF2bdk scaffold. Photophysical characterization revealed that both probes exhibit pronounced polarity sensitivity, with their Stokes shifts increasing as the solvent polarity parameter (orientation polarizability) rises. Among them, XH-2, which displays higher polarity & sdot;correlation than & sdot;XH-1, was successfully applied to the detection of trace amounts of methanol and water in organic solvents. In addition, XH-1, featuring Near-Infrared (NIR) emission, demonstrated excellent lysosome-targeting ability and robust two-photon imaging performance. This work expands the understanding of the photophysical properties of D-pi-A-pi-D fluorescent molecules based on the coumarin-BF2bdk skeleton and enriches the application potential of such conjugated systems.

Based on a cyclic chalcone framework, the dye named CCF was constructed using 1,3-indanedione and 4-(9H-carbazol-9-yl)benzaldehyde. Quantum chemical calculations revealed its optimized molecular configuration and pronounced intramolecular charge transfer (ICT) characteristics. CCF exhibits significant polarity sensitivity, attributed to its substantial dipole moment (2.89 D). Leveraging this property, a fluorescent fingerprint powder, CCF-MMT, was prepared by combining CCF with montmorillonite. This composite exhibits a responsive color-change behavior when interacting with latent fingerprints: upon contact with sebaceous present in fingerprint residues, its fluorescence shifts from dark red to moderate red. This visual enhancement enables high-quality fingerprint development even on rough or curved surfaces where excess powder may adhere. Furthermore, the red fluorescence emission effectively suppresses interference from the blue fluorescence background commonly caused by commercial additives. With its high resolution, visual enhancement, exceptional contrast, broad adaptability, real-time development capability, and cost-effectiveness, CCF-MMT provides a high-quality solution for latent fingerprint visualization, positioning it as an ideal choice for complex crime scene investigations.

Benefiting from their wide operation window, multifunctionality and high stability, hydrogel electrolytes have been widely adopted in zinc-ion batteries (ZIBs) to suppress dendrite growth and mitigate water-related side reactions. However, achieving ZIBs with both long cycle life and high cycling stability remains a significant challenge. Herein, we propose a strategy of combining solvation structure reconstruction with Zn deposition orientation regulation, achieved by developing a dynamic cross-linking network structure. In the prepared polyacrylamide-L-carrageenan (PAM-LC) hydrogel, L-carrageenan (LC) with three sulfonic acid groups (-SO3-) has a strong interaction with Zn2+, which alters the Zn2+ solvation structure and constructs a unique ion transfer channel, facilitating fast ion migration and enabling directional Zn crystal growth. Additionally, the strong affinity for H2O efficiently disrupts H2O-H2O hydrogen bonds, reducing H2O activity and suppressing hydrogen evolution. Together with the formation of a robust ZnCO3/ZnS solid-electrolyte interphase (SEI), ZIBs with PAM-LC hydrogel electrolyte exhibit superior electrochemical performance. The Zn//Zn symmetric cell achieves an ultralong cycle life of 9350 hat 0.5 mA cm-2/0.5 mAh cm-2; the Zn//Cu cell operates stably for over 820 h with a coulombic efficiency of 99.33 %; the Zn//V-EG (ethylene glycol (EG)-preinserted V2O5) full cell delivers a high specific capacity of 466 mAh g-1 at 0.3 A g-1; and the flexible batteries remain stable under bending, compressing and even cutting conditions.

Using a skeleton transition strategy, a series of cyclic amide-containing isoxazoline derivatives were rationally designed and synthesized. Bioassay results revealed that several compounds exhibited potent insecticidal activity and a broad spectrum of action. Notably, compound I-22 showed remarkable insecticidal efficacy against Plutella xylostella and Tetranychus cinnabarinus, with LC50 values of 0.13 mg/L and 0.55 mg/L, respectively, significantly surpassing fluxametamide (LC50 = 0.73 mg/L and 0.81 mg/L, respectively). Moreover, the acute contact toxicity of compound I-22 to honeybees was slightly lower, with an LD50 of 1.46 μg/bee compared to fluxametamide (LD50 = 1.18 μg/bee). Molecular docking studies indicated that both fluxametamide and I-22 act on GABA receptors, and their similar docking conformations may explain the comparable honeybee toxicity. Theoretical calculations further suggested that the 5-ethylpyridine moiety plays a critical role in enhancing insecticidal activity and target selectivity. Collectively, these findings highlight compound I-22 as a promising candidate for the development of a novel isoxazoline insecticide.

To monitor the close correlation between viscosity and the processing, spoilage of food as well as diseases in biological systems, this study designed two dual-responsive fluorescent probes (YB-P and YB-U) with a chalcone scaffold based on the intramolecular charge transfer (ICT) mechanism, which exhibit both viscosity- and polarity-sensitive properties. The probes were successfully applied to monitor the freshness of beverages such as orange juice and green tea, and to evaluate the thickening capacity, type and mass concentration of food thickeners including pectin and xanthan gum and so on. Notably, YB-P, with its excellent photostability, achieved two-photon fluorescence lifetime imaging to track intracellular viscosity enhancement induced by nystatin and monensin. The high selectivity and stability of these probes provide an efficient tool for viscosity and polarity monitoring in complex systems.

The complexation behaviors between four local anesthetics and pagoda[5]arene were investigated using H-1 NMR spectroscopy, fluorescence spectroscopy, and density functional theory calculations. Among the four selected local anesthetics, only tetracaine and procaine were found to form stable 1:1 host-guest complexes with pagoda[5]arene. Structural analyses revealed that the alkylammonium moieties of these two ester-type anesthetic guest molecules could be encapsulated within the electron-rich cavity of pagoda[5]arene. The stability of the resulting complexes arises from the synergistic contributions of multiple noncovalent interactions, including C-H & centerdot;& centerdot;& centerdot;pi interactions, pi & centerdot;& centerdot;& centerdot;pi interactions, and hydrogen bonding. This selective binding behavior provides new practical opportunities for applications in pharmaceutical analysis, clinical safety monitoring, and drug quality control.

Multistimuli responsive luminescent materials have attracted increasing attention for their unique optical properties to meet diversified applications. The design and synthesis of multistimuli fluorescent materials based on simple solid-state fluorophores remains necessary and challenging. In this work, a series of AIE active organic responsive fluorescent molecules with unsymmetric diarylvinyl anthracene structure were synthesized. These compounds have good substituent-dependent solid-state emission with various colors including green, yellow and tangerine. Compound FAN-NEt2 has acidochromic properties, and its emission color could be changed rapidly between tangerine and yellow for many times with the alternating fumigation of acid and base. This molecule could be used as acid-sensitive fluorescent sensor and encrypted ink. Moreover, the composites of these molecules and lauric acid exhibit thermochromic properties, and they could show obvious color changes with heating and cooling. The fluorescent emission of FAN-NEt2/lauric acid mixture could be changed quickly when heated to 40 degrees C. The microcapsules of FAN-NEt2/lauric acid composite and melamine were prepared, which could be used as thermal sensors to detect the surface temperature of glass containers. This work provides a series of stimuli responsive luminescent materials based on unsymmetric diarylvinyl anthracene structure, which have potential applications in practical scenarios.

Sul-pH is a pH-sensitive fluorescent probe designed to detect mildly alkaline environments through a protonation-deprotonation mechanism. The probe is constructed using an ICT-based molecular design, with a cyclic chalcone serving as the parent fluorophore. Sul-pH exhibits a pH response range of 7-10, during which its fluorescence intensity at 601 nm increases by nearly 250-fold as the pH shifts from neutral to alkaline, accompanied by a pronounced visual color change. Moreover, the pH-responsive behavior of Sul-pH was correlated with the alkalinity generated during the hydrolysis of sulfide ions, enabling its application in the quantitative detection of S2-. The probe responds specifically to the alkaline conditions produced by S2- hydrolysis, thereby eliminating interference from HS- during sulfide detection. Impressively, Sul-pH displays a rapid response within 6 s and demonstrates excellent pH cycling stability as well as photostability. Sul-pH also shows good performance in detecting S2- in real water samples. Furthermore, Sul-pH can detect both S2- and pH in living cells, providing a reliable tool for monitoring intracellular pH dynamics and sulfide ion fluctuations within biological systems.

Despite the high specific capacity of V-based cathodes, their practical application in aqueous Zn-ion batteries is often hindered by unstable electrode/electrolyte interfaces and irreversible cathode dissolution. Herein, we propose a facile strategy involving the pre-insertion of propylene glycol (PG) into the V2O5 framework (denoted as V-PG) to construct an in situ ZnS-rich cathode-electrolyte interface (CEI), conceptually derived from the protective solid-electrolyte interface (SEI) on anodes. Notably, the electrically neutral PG with reducing properties facilitates electrolyte decomposition; together with the localized weakly reductive environment in V-PG, this promotes the reduction of SO4 2- to S2- and the formation of ZnS-rich CEI. Experimental and theoretical calculations further demonstrate that the zincophilic nature of ZnS-rich CEI, combined with PG insertion, not only accelerates ion transport kinetics but also inhibits cathode dissolution, as evidenced by rapid ion diffusion kinetics (10-8 cm2 s-1), and enhanced cycle stability (retaining 86.9% capacity after 300 cycles at 1 A g-1). This work not only reports a general strategy to construct the CEI layer for suppressing V-based cathode dissolution but also provides new insights for designing stable/functional CEIs by adapting an effective SEI concept to cathode materials.

Cellular viscosity is a dynamic biological parameter that is closely related to cell function, metabolism, and certain diseases. The changes in viscosity that occur within cells are closely related to the metabolic stability within the cells. Therefore, developing detection tools capable of real-time monitoring of viscosity changes is crucial for a better understanding of the pathologies associated with certain diseases caused by altered viscosity. This paper developed a new type of fluorescent probe, YB-Z. This fluorescent probe has a donor-it-acceptor (Dit-A) structure. By introducing a morpholine moiety onto the fluorophore as a rotary group, the TICT effect between the morpholine moiety and the main fluorophore skeleton endows the probe with exceptional viscosity sensitivity. As the viscosity of the medium increases, the fluorescence intensity of YB-Z increases significantly (by approximately 30 times), and the fluorescence lifetime is also significantly prolonged. Both phenomena were in a good linear relationship with the viscosity. Therefore, by leveraging the lysosome-targeting properties of the morpholine group and the high viscosity sensitivity of YB-Z, we successfully achieved lysosome targeting and tracked changes in intracellular viscosity caused by monensin sodium using two fluorescence-related detection indicators (fluorescence intensity and fluorescence lifetime).

The performance of zinc ion batteries (ZIBs) is significantly constrained by dendrite growth and side reactions on the Zn anode. While epitaxial growth is an efficient strategy to stabilize the Zn anode by directing crystal alignment, the direct contact between the exposed crystal and electrolyte results in severe parasitic reactions. Here, we present a selective etching strategy on Zn anodes (denoted as ACE-Zn) that preferentially exposes the (101) plane, which features strong epitaxial growth characteristics to facilitate stably dense stacking of Zn atoms. Notably, the (101) plane also promotes the formation of a ZnS solid electrolyte interphase (SEI). This ZnS SEI exhibits high hydrophilicity and an ultrathin structure, contributing to exceptional ion transfer rate and isolating the Zn anode from water-related side reactions. As a result, ACE-Zn symmetric cells achieve an impressive cycle life of 4920 hat 0.5 mAh cm-2 and 0.5 mA cm-2, along with a high average Coulombic efficiency (CE) of 99.93 % over 3500 cycles. Furthermore, V-EG//ACE-Zn button-cells demonstrate prolonged cycle life of 7600 cycles at 10 A g-1. We believe this "one stone, two birds" strategy will provide new insights into texturing preferential planes and constructing SEI to stabilize Zn anodes.

Stimuli-responsive organic luminescent materials have attracted much attention for their practical application in many fields. Acidochromic materials show color or fluorescence changes with the stimuli of external acid, and have wide applications in information encryption and anti-counterfeiting technology. In this work, two coumarin acylhydrazone derivatives were designed and synthesized. These compounds can emit strong blue fluorescence in weakly polar solvents with high fluorescence quantum yield, and show red-shifted fluorescence in highly polar solvents with low intensity, which is characterized as solvatochromism. The DFT calculations show that these molecules have a significant difference in HOMO and LUMO distributions, which suggests that they have the property of intramolecular charge transfer. Further studies showed that these compounds also possessed acidochromic properties. After encountering trifluoroacetic acid, the fluorescence intensity of these compounds could gradually decrease. The solutions of these compounds can be used as security inks. The fluorescent powders prepared from these compounds and montmorillonite showed a significantly different sensitivity to trifluoroacetic acid, and can be used as information encryption and anti-counterfeiting fluorescent materials.

As a potent reactive oxygen species (ROS), peroxynitrite (ONOO-) is produced when superoxide anions (O2 center dot- ) react with nitric oxide (NO). This molecule has been demonstrated to be closely linked to the progression of numerous diseases. Peroxynitrite is highly reactive and quite unstable with a very short half-life, which is primarily found within mitochondria. Therefore, creating a mitochondria-targeted fluorescent probe that can selectively detect peroxynitrite is of great importance. In this work, a ratiometric fluorescent probe RHON is designed to detect ONOO-both sensitively and selectively. The probe, featuring an oxabenzofluorene-based structure, was efficiently synthesized in a few short steps. After the addition of ONOO-, the pinkish-purple colour of the probe solution gradually disappeared and finally became colourless. Simultaneously, a substantial blue shift was observed in the fluorescence emission, covering a range of 115 nm. After thorough evaluations, the probe was found to have outstanding selectivity and sensitivity toward ONOO-.Impressively, it can reach an extremely low detection limit of 0.11 nM, and its response time is quite rapid, approximately 1 min. Furthermore, RHON exhibits outstanding biocompatibility. Moreover, the exogenous ONOO-present in mitochondria of living cells could be successfully detected by this probe. This successful application vividly demonstrates the great potential of RHON in the field of biological applications.