摘要 : Background Emerging pollutants such as enrofloxacin (ENR) pose a serious threat to the ecosystem and public health due to their resistance to degradation and tendency to accumulate in the environment. Although existing antibiotic detection techniques have considerable application value, they suffer from high costs, complex operation procedures, or insufficient sensitivity. Therefore, there is an urgent need to develop a new detection method that is simple, rapid, low-cost, and environmentally friendly to efficiently monitor antibiotic pollution in environmental water bodies and safeguard public health. Results In this work, inspired by the superior catalytic activity of three-dimensional (3D) composite nanomaterials, we rationally designed and synthesized FeMoO 4 /Fe 7 S 8 nanosheet flower composites (3D FeMoO 4 /Fe 7 S 8 NSFs) as a novel peroxidase-mimicking nanozyme for the sensitive colorimetric detection of ENR. The as-synthesized NSFs exhibit outstanding intrinsic peroxidase-like activity, enabling their direct integration into a colorimetric sensing platform. Critically, the synergistic redox coupling between Mo 6+ /Mo 4+ and the Fe 2+ /Fe 3+ couple facilitates rapid electron transfer, thereby promoting efficient activation of peroxymonosulfate (PMS) to generate reactive oxygen species—including hydroxyl radicals (·OH), sulfate radicals (·SO 4 − ), singlet oxygen ( 1 O 2 ), and superoxide radicals (·O 2 − ), which collectively drive the oxidation of chromogenic substrates without requiring external enzymatic or chemical initiators. This mechanism underpins a robust, single-step colorimetric assay that overcomes key limitations of conventional methods, such as stringent temperature control, prolonged reaction times, and narrow pH operational windows, thus enabling rapid, reliable ENR quantification. The optimized sensing platform delivers a wide linear range (0.500–70.0 μM), a low detection limit (LOD) of 0.150 μM (S/N = 3), and a total assay time of only 5 min. Significance This system breaks through the limitations of traditional methods in terms of temperature, time, and pH conditions, and successfully generates free radicals and non-free radical active substances by activating PMS, thereby achieving rapid and efficient detection of antibiotics. This innovation provides a highly promising new strategy for the identification of fluoroquinolone (FQs) antibiotics and shows broad application prospects in the field of environmental pollutant detection and monitoring.

摘要 : Hydrogen peroxide (H 2 O 2 ) is an attractive green oxidant, yet sustainable on-site photoproduction is often limited by inefficient charge separation and insufficient selectivity toward the two-electron oxygen reduction reaction (2e − ORR). Here we propose that an atomically coherent PHI/PTI (heptazine/triazine) carbon-nitride homojunction can create a built-in electric field to suppress recombination and steer O 2 reduction toward H 2 O 2 . Using a KCl/LiCl molten-salt reconstruction strategy, we in situ construct this PHI/PTI homojunction in polymeric carbon nitride and obtain an optimized catalyst (PCN 1K-2Li ). Under visible light (λ > 420 nm), PCN 1K-2Li achieves H 2 O 2 formation rates of 7498.6 μmol g −1 h −1 in 5 vol% ethanol and 8900.96 μmol g −1 h −1 in 5 vol% benzyl alcohol, representing a 234-fold enhancement over pristine PCN under comparable conditions. RRDE and mechanistic analyses indicate ~80% H 2 O 2 selectivity with an electron-transfer number close to 2, consistent with a dominant 2e − ORR via an • O 2 − -mediated pathway. The catalyst remains effective in pure water and 3.5% NaCl, and enables sustained H 2 O 2 accumulation under natural sunlight (up to 1538.40 μmol in benzyl-alcohol media over 9 h), highlighting its robustness across practical environments.

摘要 : Advancements in toxicology have clarified toxic effects across biological levels; however, the mechanisms driving chemical-mixture toxicity remain unclear. In addition, the concentration addition (CA) model commonly used in mixture risk assessment may introduce predictive bias by neglecting chemical interactions, yet the implications of such bias remain poorly understood. Using zebrafish as a model organism, we systematically assessed triclocarban (TCC) and bisphenol S (BPS) mixtures. The results showed that mixtures prepared at concentrations predicted by the CA model caused synergistic toxicity across multiple biological levels. Transcriptomics showed TCC and BPS shared limited similarity, differing mainly in functional attributes rather than differentially expressed gene numbers. Mixture exposure amplified transcriptional responses and introduced new biological processes, revealing molecular mechanisms driving synergism. Notably, metabolism, MAPK, calcium, Apelin, and FoxO pathways were significantly enriched, collectively promoting oxidative stress and apoptosis. These processes further synergistically mediated multi-system toxicity through interconnected pathways, manifested as cardiovascular abnormalities (elevated heart rate, pericardial edema, caudal vein constriction), immune dysregulation (proliferation of innate immune cells with cytokine alterations), and neurotoxicity (impaired neuronal development, dopamine depletion, and elevated GABA). These synergistic effects further induced malformations in organs such as the swim bladders and yolk sac, disrupted normal physiological activities, and ultimately impaired embryonic development, leading to increased mortality. By contrast, applying the combination index (CI) as a correction factor shifted the combined effects predominantly toward additivity or antagonism. Overall, this study provides mechanistic insights into TCC-BPS interactions. Predictions based on the addition model may overlook chemical interactions, causing toxicological biases, while CI provides a validated correction across biological levels, highlighting its utility in mixture risk assessment.

摘要 : Rapid in-situ detection is the development trend of modern environmental monitoring technology. Conventional detection technologies are often hindered by high costs and operational complexity, limiting their practical applicability. In this context, carbon-based nanozymes have emerged as a promising class of functional materials that combine the unique properties of nanomaterials with enzyme-mimicking catalytic activities. Through controlled synthesis scenarios, such as hydrothermal methods and chemical vapor deposition, precise modulation of their structural features can be achieved. Owing to their characteristics of high stability, low cost, and easy functionalization, carbon-based nanozymes can effectively mimic the activities of various enzymes, including the catalytic properties of peroxidase, oxidase, catalase, and glucose oxidase. Researches indicate that they exhibit remarkable sensitivity and selectivity in colorimetric and fluorescence sensing, enabling the effective detection of environmental pollutants such as heavy metal ions, organic pollutants, and pesticide residues. This review comprehensively summarizes recent advances in carbon-based nanozymes, with emphasis on synthetic scenarios, multienzyme-mimetic activities, and colorimetric and fluorometric sensing applications in environmental monitoring. Studies have been conducted on synthesis parameters, material structures, enzyme-mimicking behaviors, and reaction kinetics, while also exploring the promoting and competitive roles of carbon-based nanozymes in the sensing and detection of environmental pollutants. To address key challenges such as biocompatibility and large-scale production, future exploration should focus on synergistic breakthroughs in functional integration and performance enhancement to advance the practical application of this technology in the sensing and assay of environmental pollutants.

摘要 : Natural iron mineral are ubiquitous components in aquatic environments and have been documented to play a prominent role in the degradation of organic contaminants owing to their compositional and structural versatility and redox-active nature. Although pyrite-mediated Fenton-like reaction have become a hot topic for wastewater treatment, the inherent iron-ion dissolution and releasing characteristics usually cause active-site restructuring, thus limiting long-term operational potential. By constructing pyrite/hematite composite mineral, we achieved efficient month-long photo-Fenton degradation. Based on the relevance of iron ions to free radical, it was confirmed regarding the dynamic switching from homogeneous (leached Fe 2 + /H 2 O 2 ) to heterogeneous reaction (surficial Fe/H 2 O 2 ) during long-term system. The spontaneously formed sulfur vacancies were a dominant factor for re-capturing aqueous iron ions. Meanwhile, interfacial Fe–S–Fe–O bonds accelerate electrons transform between pyrite and hematite for accelerating surface Fe cycling. Consequently, the composite mineral showed superior potential applications to actual industrial wastewater for its broad resistance to environmental interferents. Furthermore, the composite minerals formed by natural pyrite from different regions of China and commercial hematite exhibit a generally high degradation efficiency. This work provides theoretical support for studying the degradation mechanisms of pyrite-based Fenton chemistry during a long-term process, meanwhile promoting the upgrading of natural irons mineral.

摘要 : Pyrethroid insecticides are widely applied in agricultural production; however, they remain highly toxic to aquatic organisms. Therefore, the development of rapid on-site detection methods of pyrethroids is crucial for environmental risk assessment and regulatory monitoring. To address this issue, a novel strategy was designed based on fluorescent variations of silicon quantum dots (SiQDs). A series of SiQDs functionalized with phenylhydrazine derivatives were fabricated and evaluated, among which the optimized LOD was 0.13 μM (6.57 μg/kg). The structure-property relationship was systematically elucidated through theoretical calculations integrated with machine learning approaches. By employing a smartphone-assisted portable fluorescence device, on-site and real-time monitoring of pyrethroids’ residues in real-world waters and olives was successfully achieved with high accuracy and precision. Using zebrafish ( Danio rerio ) as a model invertebrate, toxicological assessment confirmed the environmental friendliness of the newly developed method. Therefore, the present approach holds great promise for applications in environmental protection, and the advancement of green pest control technologies.

摘要 : Herein, we pioneered a P-doped heteronuclear Fe-Co dual-atom nanozyme (FeCoP-NC), in which 0.1 % P-doping substantially increased oxidase-like (OXD) activity by 48.3 % compared to FeCo-NC. The enhanced OXD activity resulted from a synergistic dual-pathway mechanism involving direct two-electron transfer and ·O 2 − mediation at FeN 3 P-CoN 3 P active sites. By utilizing FeCoP-NC's high OXD activity and differential coloring of two chromogenic agents (TMB and DPD), a three-channel colorimetric sensing array was constructed, achieving high-selectivity discrimination of five organophosphorus pesticides (OPs) in environmental/food samples, with a detection limit of 3.3 nM. Owing to the independence of the colorimetric reactions of TMB and DPD, a "blue TMB gel-pink DPD solution" integrated kit was developed, exhibiting distinctly spatial separation of two-phase chromogenic signals. This smartphone-based device enabled rapid malathion detection with a detection limit of 0.17 μM. Utilizing zebrafish ( Danio rerio ) as model invertebrates, the biocompatibility of FeCoP-NC-based colorimetric system was confirmed through embryonic-larval morphological observations, swim behavior, and light/dark stimulation responses. BAGI analysis further demonstrated its greenness with a score of 80, providing novel insights into the design of green nanozymes and on-site detection of OPs residues in environmental and food media.

摘要 : Herein, we systematically compared the cardiotoxicity effects of two structurally similar organophosphate flame retardants (OPFRs' EHDPP and its major metabolite DPHP) using zebrafishi as a model organism. Predictive toxicity data from two aquatic species, together with empirical LC50 values obtained in zebrafish larvae, consistently demonstrated that 2-ethylhexyl diphenyl phosphate (EHDPP) is substantially more toxic than diphenyl phosphate (DPHP). At LC50-scaled concentrations, both contaminants induced the reduced heart rate, pericardial edema, and cardiac malformations, in concomitant with enhanced activities of creatine kinase (CK) and lactate dehydrogenase (LDH) and downregulated cardiac transcription factors ( gata4 and Nkx2.5 ) and upregulated structural gene cmlc2 . Even at low concentrations, EHDPP triggered apoptosis and elevated reactive oxygen species (ROS) levels in cardiac and pericardial tisues, along with prominent lipid accumulation in the heart, vasculature, and intersegmental arteries. It activated multiple pathways including MAPK, calcium signaling, and excitation-contraction coupling, while DPHP primarily affected cardiac function via calcium pump regulation and neuro-signaling pathways. Disease ontology (DO) enrichment analysis revealed that both EHDPP and DPHP associated target genes were most significantly enriched in cardiovascular-related diseases. Pharmacological rescue experiments using pathway-specific agents (Y-27632 and isoproterenol) further validated the functional roles of key signaling pathways in mediating the observed cardiotoxicity. Albeit differing in only one alkyl chain, EHDPP and DPHP displayed significantly differential cardiotoxicity and molecular mechanisms in zebrafish. These observations are conducive to illustrating OPFRs' structure-activity relationship and their health risk.

摘要 : Diphenyl Phosphate (DPhP), as a major metabolite and environmental pollutant of aromatic organophosphorus flame retardants, has garnered considerable attention due to its widespread occurrence in environmental matrices and potential health risks. In this study, we established an integrative framework combining network toxicology, transcriptomics, and zebrafish assays to elucidate the toxicological mechanisms of DPhP. Network toxicology and transcriptomic analyses consistently revealed that DPhP-responsive genes were predominantly enriched in pathways governing cellular energy homeostasis, including glucose-lipid metabolism and mitochondrial oxidative phosphorylation. These results collectively suggest that DPhP perturbs glucose and lipid metabolic processes, impairs mitochondrial function, and compromises ATP-generating capacity. In vivo validation using zebrafish further demonstrated pronounced metabolic reprogramming following DPhP exposure. At 25 μM, DPhP significantly elevated whole-body glucose (∼1.3-fold vs. control) and pyruvate levels (∼5-fold), and induced hepatic lipid accumulation, as evidenced by increased triglyceride (TG; ∼3-fold) and total cholesterol (T-CHO; ∼3-fold) concentrations. This metabolic shift was accompanied by a marked decline in mitochondrial membrane potential, inhibition of electron transport chain activity, and a substantial reduction in ATP content (to less than 25% of control). These metabolic perturbations ultimately manifested as pericardial edema, impaired growth, vascular abnormalities, and concentration-dependent behavioral alterations. By delineating the cascade from mitochondrial dysfunction to systemic energy imbalance and multi-organ toxicity, this study provides novel mechanistic insights into the action of DPhP. Furthermore, the integrative paradigm linking chemical structure analysis, target prediction, omics profiling, and in vivo validation offers a versatile methodological framework for advancing mechanistic toxicology research and environmental risk assessment of emerging contaminants.