β3-Adrenergic receptors (β3-ARs), as a subclass of G protein-coupled receptors (GPCRs), play a pivotal role in regulating oxidative stress. However, the dynamic interplay between their microenvironmental fluctuations and glioma mechanisms remains poorly understood. Here, we report the development of GSHP, a blood-brain barrier (BBB)-permeable probe that simultaneously visualizes β3-ARs and reversibly monitors the surrounding redox status in real-time. This dual-responsive probe enables reversible dynamic imaging of redox homeostasis around β3-ARs in living cells under stress conditions, providing direct visual evidence for redox adaptation. Using GSHP for high-throughput screening, we identified and validated baicalin as a potent β3-AR natural inhibitor that induces glutathione depletion and triggers oxidative stress-mediated apoptosis via the Gαi/o-extracellular signal-regulated kinase (ERK)-nuclear factor erythroid 2-related factor 2 (Nrf2)-glutamate-cysteine ligase catalytic subunit (GCLc) signaling pathway in U251 glioblastoma cells. In orthotopic U251 glioma mouse models, GSHP penetrated the brain and enabled dual-channel imaging of β3-AR overexpression and redox imbalance in vivo, allowing for effective glioma discrimination and demonstrating its potential for therapeutic monitoring. GSHP thus serves as a versatile platform for studying β3-AR-related redox biology and facilitating therapeutic discovery in brain diseases.

A serial of oxadiazol-2-ones/oxadiazole-2-thiones were designed, synthesized and evaluated as urease inhibitors. Out of these compounds, oxadiazole-2-thiones showed excellent inhibition against urease with twenty-two showing higher potency than the clinical used drug AHA. It is emphasized that 1,3,4-oxadiazole-2-thiones containing 3-propylphenoxy (d34) and 3-nitrophenoxy (d46) on the side chain were the two most active compounds. They were demonstrated having 230- and 360-fold higher potency than AHA and inhibiting urease with a mixed mechanism.

Alcoholic liver disease (ALD) is closely associated with oxidative stress, a process that not only exacerbates liver damage but also increases the risk of developing inflammation. Hydrogen sulfide (H2S) and glutathione (GSH), as key redox regulatory factors, play central roles in maintaining cellular redox homeostasis and regulating inflammation. However, due to their similar chemical properties, achieving simultaneous and highly selective monitoring of them still faces enormous challenges. To address this issue, we have developed a single-excitation, dual-emission fluorescent probe (YF-O) capable of selectively detecting H2S and GSH with distinct emission signals at 600 nm and 705 nm, respectively. YF-O exhibits high sensitivity, with detection limits of 0.035 mu M for H2S and 0.065 mu M for GSH, respectively, along with a rapid response time of 240 s and a large Stokes shift, enabling reliable discrimination between the two analytes. YF-O can sensitively respond to analyte fluctuations, making it suitable for real-time metabolic monitoring in cells and various in vivo models. Mouse models of ALD and acute inflammation were established for imaging application, and the results indicated that YF-O effectively monitored and reflected the dynamic changes in glutathione depletion and elevated hydrogen sulfide levels during the progression of ALD and inflammation. This highlighted the tremendous potential of YF-O as a dual-detection molecular probe, offering promise for monitoring redox-related pathological changes and evaluating therapeutic efficacy.

Abstract Covalent organic frameworks (COFs) have attracted considerable attention as promising photocatalysts for hydrogen peroxide (H2O2) production. To further improve their catalytic performance, a quaternary ammonium functionality was introduced into the bipyridine units of the COF via a post-synthetic modification strategy. Under identical irradiation conditions, the cationized Pry-COF-QA achieved a H2O2 production rate of 7.31 mmol·h–1·g–1, which is markedly higher than that of the non-protonated Pry-COF (5.50 mmol·h–1·g–1). To gain mechanistic insight into the enhanced activity, density functional theory (DFT) calculations were performed. The results indicate that the incorporation of the quaternary ammonium group fundamentally reconfigures the photophysical behavior. In addition to inducing a red shift in the absorption spectrum by narrowing the HOMO–LUMO energy gap, it more importantly converts the excitation character from a localized excitation (LE) state, which is unfavorable for charge separation, to an intramolecular charge transfer (ICT) state with well-separated spatial distribution. This efficient ICT pathway effectively suppresses electron–hole recombination, thereby significantly prolonging the lifetime of photogenerated charge carriers and ultimately facilitating efficient photocatalytic H2O2 production, while also providing a valuable guideline for the rational design of COF-based systems toward efficient photocatalytic H2O2 generation.

The ability to visualize organelles and their microenvironments with high spatiotemporal resolution is crucial for deciphering cellular physiology and disease mechanisms. Organic small-molecule fluorescent probes provide versatile tools for this purpose because their modular structures can integrate a fluorophore, an organelle-targeting motif, a linker, and a recognition or microenvironment-responsive unit. This review summarizes recent advances in single-organelle and dual-organelle fluorescent probes for subcellular imaging. Single-organelle probes are discussed according to the organelle involved and the representative parameter or analyte detected, including membrane potential, viscosity, polarity, pH, reactive oxygen/nitrogen species, metal ions, nucleic acids, and membrane-associated components. Dual-organelle probes are organized according to biologically meaningful organelle pairs and are further interpreted by their design logic, including simultaneous dual-color staining, stimulus-induced probe translocation, and ratiometric or lifetime-based readouts. Particular attention is paid to validation criteria, limitations of extrapolating cultured-cell localization to tissue-level imaging, and the distinction between organelle-specific fluorescence and bulk in vivo signal changes. By integrating design principles, representative applications, and current challenges, this review aims to provide a practical framework for the rational development of organelle-targeting fluorescent probes for mechanistic cell biology and translational imaging.

Background The role of carbon monoxide (CO) as a fundamental gasotransmitter in cellular signaling and redox homeostasis is well-established. Precise in vivo tracking of CO remains a significant challenge, as most existing fluorescent probes are limited by short emission wavelengths or small Stokes shifts, which compromise signal fidelity in deep tissues due to autofluorescence and light scattering. Results To address these critical gaps, we developed DMBT-OH-CO, a near-infrared (NIR) fluorescent probe constructed on a novel dicyanoisofuranone-aminothiophenol scaffold. This rational molecular engineering achieves a synergistic combination of long-wavelength emission at 693 nm and an exceptionally large Stokes shift of 193 nm, effectively eliminating spectral crosstalk and excitation interference to ensure high-fidelity imaging. Utilizing a palladium-mediated Tsuji-Trost deallylation mechanism, the probe exhibits a rapid response, high selectivity over various biological interferents, and a competitive detection limit of 210 nM. Furthermore, DMBT-OH-CO demonstrates excellent biocompatibility and superior deep-tissue penetration. We successfully applied this tool to visualize endogenous CO upregulation in LPS-stimulated cells and, significantly, to monitor real-time, non-invasive CO fluctuations in a zebrafish inflammation model. These results validate the probe’s efficacy in capturing dynamic gasotransmitter changes within complex physiological environments with high spatio-temporal resolution. Significance and Novelty This work introduces a novel NIR imaging platform, DMBT-OH-CO, distinguished by its ultra-large Stokes shift and superior optical resolution. By overcoming the penetration limits of traditional probes, it enables the precise visualization of CO in deep tissues. Our findings provide a powerful chemical tool for elucidating the complex pathological roles of CO in inflammation, offering significant potential for future biomedical research and the diagnosis of gasotransmitter-related diseases.

Superoxide anion (O-2(center dot-)) plays a critical role in cellular signaling and function, yet its detection in vivo remains challenging due to its low concentration, short half-life, and high reactivity, driving the need for sensitive, selective, and real-time analytical methods. In this study, we report a small-molecule fluorescent probe, designated PQSP, based on a pyrroloquinoline scaffold, for the detection of O-2(center dot-). Spectroscopic analysis revealed that the probe responds rapidly and selectively to O-2(center dot-), with no significant interference from common amino acids, cations, anions, or other reactive oxygen species. Following cytotoxicity evaluation, PQSP was successfully applied for real-time monitoring of O-2(center dot-) levels in live HepG2 cells and 3-day-old zebrafish larvae. Furthermore, PQSP demonstrated the capability to detect O-2(center dot-) generated under inflammatory conditions. This work provides a promising molecular tool for studying oxidative stress-related pathophysiology and developing related diagnostic approaches.

Glioblastoma (GBM) is an aggressive brain tumor whose invasive growth results in poor surgical outcomes and prognosis, necessitating new diagnostic and therapeutic tools. Superoxide anion (O-2(center dot-)), a key reactive oxygen species, plays a central role in glioma progression, with its levels being significantly elevated in tumor tissue. We designed and synthesized a novel fluorescent probe, W5, which exhibits high selectivity (similar to 100-fold) and high sensitivity (LOD: 34.2 nM) for O-2(center dot-), generating a "turn-on" fluorescence signal with a large Stokes shift (similar to 110 nm) via a spontaneous cyclization reaction. To achieve brain tumor targeting, W5 was encapsulated within transferrin (Tf) nanoparticles, forming stable nanoparticles named Tf-W5 of approximately 58 nm in diameter, a size suitable for delivery across the blood-brain barrier. The probe elucidated the iron-dependent and autophagy-regulated mechanisms of lysosomal O-2(center dot-) during ferroptosis in glioma cells and achieved high-contrast imaging of orthotopic gliomas in animal models pre-treated with TMZ. Tf-W5 successfully guided the precise resection of tumors, with a two-photon imaging depth of up to 320 mu m. In conclusion, Tf-W5 serves as a multifunctional platform, acting as both a powerful tool for dissecting the redox biology of glioma and a promising solution for achieving precise diagnosis and surgical guidance.

Ethylene, as a crucial plant hormone, plays a significant role in regulating plant growth, development, and stress responses. In this study, we developed a novel two-photon fluorescent probe, ETP, based on a naphthalene fluorophore, to detect ethylene fluctuations in plants with high sensitivity and specificity. Experimental results demonstrated that ETP could efficiently penetrate plant cells, exhibiting a marked increase in the fluorescence intensity corresponding to rising ethylene levels. Given that AOX1A (Alternative Oxidase 1A), a key component of the ethylene signaling pathway, enhances ethylene sensitivity, we applied ETP for ethylene imaging in both wild-type and AOX1A transgenic Arabidopsis (AOX1A overexpressor). Following ACC treatment, the mutant plants exhibited significantly higher ethylene production than the wild type, and ETP successfully visualized these differences. Furthermore, fluorescence lifetime imaging experiments confirmed the robust capability of ETP in detecting ethylene variations. As an innovative fluorescent probe, ETP provides a powerful tool for investigating ethylene signaling pathways and deepening our understanding of ethylene's role in plant growth, development, and stress responses.

Early diagnosis and precise treatment of malignant tumors remain major challenges due to tumor heterogeneity and limited efficacy of conventional therapies. Here, we report a β-galactosidase (β-Gal)-activatable fluorescent probe (GalP) that integrates tumor-targeted imaging and photodynamic therapy (PDT) within a single molecular platform. GalP adopted a donor–acceptor design conjugated to a β-Gal-cleavable galactose moiety via a self-immolative linker. In its caged state, GalP enzymatic cleavage by β-Gal restores strong emission (λem = 676 nm). GalP showed high sensitivity toward β-Gal (limit of detection (LOD) = 0.0010 U/mL), excellent selectivity against potential interferents, and robust photostability. GalP produces multiple reactive oxygen species (ROS) dominated by O2•− through a type I PDT pathway, enabling effective therapy even under hypoxic conditions. GalP selectively illuminated β-Gal-overexpressing cancer cells and induced apoptosis and G2/M arrest under light irradiation, with up to ∼70 % growth inhibition. GalP also accumulated specifically at tumor sites, achieving high-contrast fluorescence imaging and potent PDT efficacy, suppressing tumor growth by 66.7 % and significantly inhibiting pulmonary metastases without systemic toxicity. This work demonstrates a robust β-Gal-responsive theranostic strategy for tumor-selective imaging and treatment, providing a promising blueprint for the rational design of enzyme-activatable probes in precision oncology.

The escalating crisis of multidrug-resistant (MDR) bacterial infections has rendered many conventional antibiotics ineffective, necessitating more agents with rapid action and low resistance potential. Here, we integrated consensus-based target identification with permeability-driven molecular optimization. Through comparative genomics and off-target exclusion, we identified highly conserved essential bacterial proteins as promising targets. High-throughput virtual screening of a natural product library (n = 582,719) followed by structure-guided modification yielded a series of oxadiazole benzoate derivatives. Umbrella sampling simulations guided membrane permeability optimization, identifying the brominated derivative Com8 with the lowest free energy barrier for transmembrane transport (ΔG = 24 kcal mol-1). Com8 exhibited potent bactericidal activity against both Pseudomonas aeruginosa and Staphylococcus aureus, with no resistance development after 20 passages. Mechanistic studies revealed that Com8 disrupts membrane integrity, causes depolarization, increases membrane permeability, and eradicates mature biofilms. In a murine S. aureus-infected wound model, Com8 significantly accelerated wound healing, reduced bacterial load, and promoted tissue regeneration without systemic toxicity. Collectively, this work establishes a rational, generalizable framework for broad-spectrum antibacterial discovery and identifies Com8 as a promising lead candidate against MDR infections.

Despite the widespread application of in-situ remediation agents for cyanobacterial bloom mitigation, many suffer from limited efficacy and potential ecological risks, underscoring the urgency to develop eco-friendly and high-performance alternatives. This study systematically compared a novel magnetic lanthanum hydroxide composite (MLC) with conventional lanthanum-modified bentonite (LMB) for phosphorus (P) removal and cyanobacterial bloom control in two experimental systems: a water-cyanobacteria (WC) system (simulating the water column) and a water-sediment-cyanobacteria (WSC) system (simulating endogenous P loading). Both agents rapidly reduced soluble reactive phosphate (SRP) in overlying water but triggered upward migration of endogenous P in sediments, which primarily in the form of non-apatite inorganic phosphorus (NAIP). Critically, LMB addition in the WSC system induced significant endogenous P release into overlying water, thereby promoting cyanobacterial proliferation. In contrast, MLC not only exhibited superior P adsorption capacity but also effectively suppressed endogenous P release. For bloom control, MLC achieved inhibition rates of 56.93% (WC system) and 88.68% (WSC system), far exceeding LMB’s modest 5.03% (WC system) and even promoting bloom growth (+ 16.11%, WSC system). Furthermore, MLC caused minimal disruption to sediment microbial communities compared to LMB. These findings demonstrated that MLC’s dual function (P immobilization and bloom inhibition) and excellent environmental compatibility make it a breakthrough material for sustainable eutrophication management in lakes.

Hydrogen sulfide (H2S) is a critical biomarker of food spoilage produced during microbial degradation of sulfur-containing proteins, leading to odor formation, quality deterioration, and potential health risks. However, current methods for H2S detection are often limited by low sensitivity, high cost, and poor portability, restricting their application in real-time food freshness monitoring. In this study, we developed a near-infrared fluorescent probe (HSP) for sensitive and on-site detection of H2S in food systems. Upon exposure to H2S, HSP exhibited a 16.6-fold fluorescence enhancement at 656 nm with a low detection limit of 0.19 mu M, along with excellent selectivity, stability, and pH tolerance. Notably, HSP could be directly sprayed onto food surfaces, where fluorescence intensity quantitatively correlated with H2S concentration, microbial activity, and storage time. The probe enabled real-time visualization of spoilage progression in fruits, grains, meat, and seafood, allowing discrimination between fresh and spoiled samples within 6-12 h. Furthermore, a smartphone-assisted platform enabled portable and intuitive freshness evaluation. This work provides a simple, low-cost, and practical strategy for real-time food spoilage monitoring.

In situ visualization of cardiolipin (CL) is critical for understanding mitochondrial function but remains limited by a lack of specific probes. Here, we report DHX-CL as the first wash-free, V-shaped near-infrared (NIR) probe specifically engineered for high-contrast in situ detection of cardiolipin. Molecular dynamics simulations and spectroscopic studies confirm that DHX-CL achieves exceptional selectivity through electrostatic and topological complementarity, with fluorescence activation triggered by restricted twisted intramolecular charge transfer (TICT). In live cells, DHX-CL outperforms the standard dye Nonyl Acridine Orange (NAO) regarding photo-stability and biocompatibility. Notably, it enables wash-free imaging and retains mitochondrial localization independent of membrane potential (Delta psi m). Collectively, this work establishes a mechanistically validated strategy for wash-free cardiolipin imaging, offering a powerful molecular tool and a new conceptual framework for probing mitochondrial lipid biology in living systems.

Inflammatory bowel disease (IBD) results from dysregulated mucosal immunity and gut microbial imbalance. Probiotic therapy, while promising, is critically limited by poor gastrointestinal survival and inadequate retention at inflamed sites. Through integrated bioinformatic analyses, we identified the ATP‑gated P2X7 receptor as a central inflammatory regulator in IBD and accordingly engineered a “sticky‑missile” armored probiotic, EcN@LHP, via a one-pot supramolecular assembly. EcN@LHP is constructed via dynamic covalent complexation of the polyphenolic P2X7 inhibitor lithospermic acid (LSA) with phenylboronic‑acid‑grafted hyaluronic acid on the surface of Escherichia coli Nissle 1917. The supramolecular armor markedly improves gastric-acid resistance and mediates targeted, “missile‑like” homing to inflamed colon through electrostatic interactions, CD44 binding, and intrinsic probiotic navigation. In the inflammatory microenvironment, elevated ROS cleave boronate ester linkages, unmasking the “sticky” catechol groups for enhanced mucoadhesion and trigger controlled release of LSA. Released LSA suppresses ATP/P2X7‑driven NLRP3 inflammasome activation, reducing macrophage pyroptosis and IL‑1β/IL‑18 secretion, thereby restoring Th17/Treg and M1/M2 immune balances. In both acute and chronic colitis models, EcN@LHP shows enhanced gastric survival, prolonged colonic residence, microbiome remodeling and attenuation of colitis and colitis‑associated tumorigenesis. This bioactive polyphenol-armoring strategy presents a promising platform to endow living therapeutics with site‑specific, on‑demand pharmacology for IBD and its complications.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline and memory impairment. While beta-amyloid (A beta) plaque deposition in the grey matter is a hallmark of AD, growing evidence suggests that substantial white matter abnormalities, particularly myelin degradation and axonal damage, also contribute to disease pathogenesis. However, the mechanistic interplay between A beta aggregation and myelin disruption remains poorly understood, largely due to the lack of molecular tools capable of concurrently mapping both pathological features with high spatial resolution. Here, we report NQPI6, a novel bifunctional, dual-emission fluorescent probe that enables simultaneous and selective imaging of myelin integrity and A beta plaques in brain tissues. NQPI6 emits a strong green fluorescence in lipid-rich myelin sheaths (lambda ex, 488 nm; lambda em 530-565 nm), allowing high-contrast, three-dimensional visualization of white matter structures. Concurrently, the probe exhibits intense red fluorescence upon binding to aggregated A beta species (lambda ex, 561 nm; lambda em, 690-730 nm), enabling the precise delineation of plaque distribution. Utilizing NQPI6 in transgenic AD model mice, we achieved co-localized imaging of A beta plaques and varying degrees of demyelination across distinct brain regions and disease stages. These spatial correlations uncovered a dynamic relationship between plaque accumulation and local myelin damage during AD progression. This work presents a powerful chemical imaging platform for investigating the spatiotemporal crosstalk between A beta deposition and myelin degeneration, offering new insights into AD pathogenesis and facilitating future diagnostic and therapeutic strategies.

Hypochlorous acid (HClO) plays an essential role in physiological and pathological processes, Dysregulated HClO production has been implicated in various disease states. Consequently, in vivo HClO monitoring is crucial for elucidating disease pathogenesis. Among various detection strategies, near-infrared (NIR) fluorescent probes offer unparalleled advantages for bio-imaging. The design of NIR-HClO fluorescent probes has garnered increasing research focus. This review provides a critical evaluation of the latest advances (2021–2025) in the design and construction of organic NIR fluorescent probes for selectively monitoring HClO. We systematically emphasize four major recognition strategies based on the oxidation of carbon-carbon unsaturated bonds, chalcogenides, nitrogen-containing groups, and phenol analogues. Furthermore, we offer a comprehensive discussion on the overarching challenges in the field, including the delicate interplay between fluorophore stability and recognition moiety reactivity, the trend towards multifunctional and theranostic probes, and the formidable quest for activatable probes in the second near-infrared (NIR-II) window. Finally, we outline future prospects, aiming to inspire innovative designs that will overcome current bottlenecks and propel the field towards clinical translation. We believe that the continued development of advanced NIR fluorescent probes remains a prominent and vital trend for future research in chemical biology and diagnostics.

Viscosity is a fundamental property in biological systems, influencing organelle function and molecular diffusion. Abnormal viscosity is associated with diseases such as metabolic disorders, neurodegeneration, and cancer. Lysosomes, central to cellular degradation and recycling, are sensitive to viscosity changes, which can disrupt enzymatic activity and cellular homeostasis. Monitoring lysosomal viscosity provides essential information on lysosomal health, helping to uncover underlying mechanisms in various diseases. Recognizing the need for effective monitoring of lysosomal viscosity changes in living cells, we have developed a near-infrared (NIR) viscosity-responsive fluorescent probe, VFLyso, specifically designed for lysosomal targeting. Based on the twisted intramolecular charge transfer (TICT) mechanism, VFLyso exhibits strong NIR fluorescence, a fast response, and a notable fluorescence response to viscosity variations (F/F0 = 65.5-fold), along with excellent selectivity and stability under physiological conditions. Our studies demonstrated that VFLyso could accurately monitor lysosomal viscosity changes in both cell cultures and animal models, including zebrafish and mouse models of fatty liver. This work not only provides a powerful tool for real-time monitoring of lysosomal viscosity but also offers valuable insights into the role of viscosity in disease progression, paving the way for potential diagnostic applications in related disorders.

Lysosomal acidification deficits are increasingly recognized as early events in Alzheimer's disease (AD), yet tools for real-time pH monitoring remain limited. Here, we report AHP, a pH-sensitive fluorescent probe with rapid response (ΔpH ≥0.2), high lysosomal specificity, ultra-large Stokes shift (>240 nm), and excellent photostability for long-term imaging. AHP enabled visualization of biphasic Aβ42-induced lysosomal pH dysregulation-initial hyperacidification followed by pathological alkalinization-directly linking acidification failure to impaired Aβ42 clearance. Dual-channel live imaging showed that reduced lysosomal acidity disrupts Aβ42 degradation, leading to cytoplasmic accumulation and increased toxicity.Using AHP-based high-throughput screening, we identified protocatechuic aldehyde as a lysosomal acidification enhancer and validated its efficacy in restoring autophagic flux. As the probe to achieve super-resolution tracking of lysosomal pH in neurodegeneration, AHP connects pH dynamics with AD pathogenesis and offers a powerful tool for mechanistic insight and drug discovery.This work establishes lysosomal pH homeostasis as a critical target in early AD intervention and highlights the broad applicability of AHP in aging-related disorders.