The Correlations between Microstructures and Color Properties of Nanocrystalline Cellulose: A Concise Review.

Cellulose nanocrystals (CNCs) are a green resource which can produce photonic crystal films with structural colors in evaporation-induced self-assembly; CNC photonic crystal films present unique structural colors that cannot be matched by other colored materials. Recently, the mechanisms of CNC photonic crystal films with a unique liquid crystal structure were investigated to obtain homogenous, stable, and even flexible films at a large scale. To clarify the mechanism of colorful CNC photonic crystal films, we briefly summarize the recent advances from the correlations among the preparation methods, microstructures, and color properties. We first discuss the preparation process of CNCs, aiming to realize the green application of resources. Then, the behavior of CNCs in the formation of liquid crystal phases is studied, considering the influence of the CNCs' size and shape, surface properties, and the types and concentrations of solvents. Finally, the film formation process of CNCs and the control of structural colors during the film formation are summarized, as well as the mechanisms of CNC photonic crystal films with full color. In summary, considering the above factors, obtaining reliable commercial CNC photonic crystal films requires a comprehensive consideration of the subsequent preparation processes starting from the preparation of CNCs.

Alien emergent aquatic plants develop better ciprofloxacin tolerance and metabolic capacity than one native submerged species.

Antibiotic pollution and biological invasion pose significant risks to freshwater biodiversity and ecosystem health. However, few studies have compared the ecological adaptability and ciprofloxacin (CIPR) degradation potential between alien and native macrophytes. We examined growth, physiological response, and CIPR accumulation, translocation and metabolic abilities of two alien plants (Eichhornia crassipes and Myriophyllum aquaticum) and one native submerged species (Vallisneria natans) exposed to CIPR at 0, 1 and 10 mg/L. We found that E. crassipes and M. aquaticum's growth were unaffected by CIPR while V. natans was significantly hindered under the 10 mg/L treatment. CIPR significantly decreased the maximal quantum yield of PSII, actual quantum yield of PSII and relative electron transfer rate in E. crassipes and V. natans but didn't impact these photosynthetic characteristics in M. aquaticum. All the plants can accumulate, translocate and metabolize CIPR. M. aquaticum and E. crassipes in the 10 mg/L treatment group showed greater CIPR accumulation potential than V. natans indicated by higher CIPR contents in their roots. The oxidative cleavage of the piperazine ring acts as a key pathway for these aquatic plants to metabolize CIPR and the metabolites mainly distributed in plant roots. M. aquaticum and E. crassipes showed a higher production of CIPR metabolites compared to V. natans, with M. aquaticum exhibiting the strongest CIPR metabolic ability, as indicated by the most extensive structural breakdown of CIPR and the largest number of potential metabolic pathways. Taken together, alien species outperformed the native species in ecological adaptability, CIPR accumulation and metabolic capacity. These findings may shed light on the successful invasion mechanisms of alien aquatic species under antibiotic pressure and highlight the potential ecological impacts of alien species, particularly M. aquaticum. Additionally, the interaction of antibiotic contamination and invasion might further challenge the native submerged macrophytes and pose greater risks to freshwater ecosystems.

Starch-based biodegradable composites: Effects of in-situ re-extrusion on structure and performance.

In this study, starch-based biodegradable composites (SDC) were prepared by extruding using thermoplastic starch (TPS, 65%wt), polylactic acid (PLA, 30%wt) and poly (butylene adipate co-terephthalate) (PBAT, 5%wt). Structure and properties of the SDC were compared by performing 1-, 2-, 3-times extrusion. The results show that in-situ re-extrusion refines the TPS in composites and reduces the size of the phase. As the number of extrusions increases, the ester bond of composites at 868 cm-1 disappears, the crystallinity increases, and the thermal stability decreases. Among the three types of composites, the mechanical properties and hydrophobic properties of the material obtained by the 2-times are the most outstanding. Compared with SDC, the elongation at break and Young's modulus of SDC-2 are significantly increased, with an increase of 8.01 % and 1.28 % in the machine direction and an increase of 11.02 % and 1.79 % in the transverse direction respectively. Additionally, water contact angle range of SDC-2 from 98.7° to 101.7°. Therefore, SDC prepared by 2-times in-situ re-extrusion has the best film properties and is an ideal packaging material. This study presents a novel method for fabricating starch-degradable composite films by in-situ re-extrusion, providing new insights into the development of starch packaging materials.

Development of a self-reinforced starch-derived film with biocompatibility and mechanical properties.

The scraps produced while processing packaging materials will cause a waste of resources. In this study, starch-based self-reinforced film (SSRF) using thermoplastic starch (TPS, 45 wt%) and polypropylene (PP, 53 wt%) was developed. The effect of extrusion times (1-4 times) on the film structure and performance was explored. The results show as the number of extrusions increases, the color of SSRF deepens from gray-white to brown, and the crystallinity increases. The mechanical properties of the four types of SSRF first increase and then decrease. The 2-SSRF has the best performance, with tensile strength of 13.23 MPa, elongation at break of 61.35%, Young's modulus of 1128.99 MPa, and flexural strength of 33.19 MPa. Proper extrusion improves the compatibility of TPS and PP. However, repeated extrusion will cause PP degradation and TPS carbonization, reducing interfacial interaction. This study developed new starch-based self-reinforced film and provided theoretical guidance for reusing packaging material scraps.

Characterizations and film-forming properties of different fractionated high-amylose maize starches subjected to hydroxypropylation.

Dual-modifications of jet milling and hydroxypropylation were used to improve the functional properties of maize starch (HM, containing 67 % amylose). The fractions obtained in three sizes (HM-S, HM-M, HM-L) were further treated with 10 % and 30 % propylene oxide (PO10 and PO30). The infrared peak of starch at 2794 cm-1 indicated the successful introduction of hydroxypropyl groups. The molar degree of substitution (MS) increased with the degree of jet milling. The MS of HM-L-PO10 is 0.4, that of HM-M-PO10 is 0.7, and that of HM-S-PO10 is 0.9. The crystallinity of dual-modified HM increased, but the crystal type remained unchanged, still being B-type. Dual-modification significantly improved the performance of starch, and the higher the degree of modification, the better the optimization effect. The lowest enthalpy changes of gelatinization (ΔH = 3.49 J/g), the best freeze-thaw stability, the highest elongation at break (110.42 %) and transmittance (81.22 %) were shown in HM-S-PO30. The present study confirms that HM-S-PO30 films have the best physicochemical and mechanical properties, which provide new insights into optimizing starch-based packaging materials.

Facile one-step synthesis of mesoporous Pt-based alloy nanospheres for ethanol electrooxidation.

Mesoporous Pt-based alloy nanospheres were prepared via a one-step soft-template strategy. The regulation of electronic structure, lattice contraction and abundant active sites endowed the mesoporous Pt-based catalysts with remarkable electrochemical activity towards ethanol oxidation reaction.

Shifting enzyme activity and microbial composition in sediment coregulate the structure of an aquatic plant community under polyethylene microplastic exposure.

It has been shown that microplastics (MPs) interfere with critical biological processes (including development, growth and fitness); however, there is no information about the impact of MPs on plant productivity and community structure in freshwater ecosystems. Here, we investigated the effects of two sizes (MIC: 20-300 µm, MAC: 2-3 mm) and three concentrations (0.03 %, 0.3 %, and 0.6 %) of low-density polyethylene MPs on submerged plant communities. The results showed that plant responses to MPs were species specific, which can affect plant community structure. For canopy-forming species (Hydrilla verticillata), total biomass increased by 4 %-46 % and relative abundance increased by 23 %-34 % under MP exposure, while rosette-forming species (Vallisneria natans) decreased by 44 %-67 % in total biomass and relative abundance decreased by 54 %-71 %. Myriophyllum spicatum growth was largely unaffected by MPs. Community diversity was negatively correlated with MAC treatments, and the community root to shoot ratio decreased by 40 %, while community productivity increased by 41 % at a 0.6 % MAC concentration. Although MPs did not change the microbial community composition, alpha diversity was reduced at the 0.6 % concentration. It is worth noting that 0.6 % is a higher concentration than most field sediment investigations. During the experiment, the activity of functional enzymes related to carbon and nitrogen increased under most MP treatments. Structural equation modelling showed that MIC changed the community structure mainly by driving sediment enzyme activity, while MAC changed the community structure mainly by driving plant growth. The results implied that MPs may affect sediment enzymatic activities, microbial alpha diversity and aquatic plant growth, potentially altering the diversity and stability of aquatic ecosystems.

A Review of Molecular Models for Gas Adsorption in Shale Nanopores and Experimental Characterization of Shale Properties.

Shale gas, as a promising alternative energy source, has received considerable attention because of its broad resource base and wide distribution. The establishment of shale models that can accurately describe the composition and structure of shale is essential to perform molecular simulations of gas adsorption in shale reservoirs. This Review provides an overview of shale models, which include organic matter models, inorganic mineral models, and composite shale models. Molecular simulations of gas adsorption performed on these models are also reviewed to provide a more comprehensive understanding of the behaviors and mechanisms of gas adsorption on shales. To accurately understand the gas adsorption behaviors in shale reservoirs, it is necessary to be aware of the pore structure characteristics of shale reservoirs. Thus, we also present experimental studies on shale microstructure analysis, including direct imaging methods and indirect measurements. The advantages, disadvantages, and applications of these methods are also well summarized. This Review is useful for understanding molecular models of gas adsorption in shales and provides guidance for selecting experimental characterization of shale structure and composition.

Microscopic Insights and Optimization of the CH4-CO2 Replacement in Natural Gas Hydrates.

Using the CO2 replacement method to exploit natural gas hydrates and store CO2 has great significance in energy access and environmental protection. Herein, the molecular dynamic method is utilized to analyze and evaluate the CH4-CO2 replacement at different constant temperatures and pressures. For optimization, various temperature oscillations are introduced in the CH4-CO2 replacement. It illustrates that increasing the temperature can improve the amounts of CH4 escape and CO2 capture but is unfavorable to the long-term CO2 storage and hydrate stability. The effects of pressure are not as significant and definite as those of temperature. Appropriate temperature oscillations can achieve comprehensive improvements, which benefit from both the deep diffusion of CO2 in the higher temperature stage and the rapid rebuilding of CO2 hydrate within just nanoseconds caused by the memory effects in the lower temperature stage. The results also reveal that the optimal lower temperature duration and frequency should be moderate. Decreasing the lower temperature value can distinctly enhance CO2 capture and hydrate stability. This study can help understand the mechanisms of CH4-CO2 replacement under different temperature and pressure conditions, especially at temperature transitions, and proposes a potentially effective method to achieve large-scale carbon sequestration in the hydrate.

Dynamic Behaviors and Mechanisms of Air-Foam Flooding at High Pressure and Reservoir Temperature via Microfluidic Experiments.

Air injection has been proven to be an effective improved oil recovery technique for deep and light oil reservoirs with low permeability and poor water injectivity. But the efficiency of air injection in highly heterogeneous reservoirs is low due to poor gas sweeping that may lead to early oxygen breakthrough caused by gas channeling and viscous fingering. Foam can be used to assist air injection to overcome the obstacles of early gas breakthrough and to increase the displacement and sweeping efficiency. In this paper, laser-etched visual microscopic pore models were used as microfluidic devices to study the air-foam flooding process in porous media at reservoir temperature and high pressure. The dynamic behaviors and relevant mechanisms of air-foam flooding were investigated. Typical mechanisms of foam generation in porous media are achieved in different parts of the micromodel, which can be listed as follows: lamella leave-behind, lamella division, and snap off. Analysis on flow states of air foam showed that foams migrate in porous media by bursting and regenerating during the flooding process. It can be observed that the flow mode of foam in porous media is the separate flow of gas and liquid through microscopic displacement experiments, suggesting that foam should not be treated as a homogeneous phase in heterogeneous porous media. The pressing, occupying, and selective blocking effects of foam in porous media exhibited different oil displacement performances with the presence of various pore geometries and networks. Tiny foams also showed stripping and carrying effects on larger oil droplets benefiting from the lipophilicity of foam. Through comprehensive analysis on overall and local oil displacement mechanisms, air-foam injection could enhance the microscopic sweep volume and improve the oil displacement efficiency.

Circ_0002111 modulates the growth process of papillary thyroid carcinoma cells by targeting the miR-363-3p/HMGB1 axis.

Previous studies have suggested that circular RNAs (circRNAs) are engaged in the progression of papillary thyroid carcinoma (PTC). However, the mechanism of circ_0002111 in PTC is still unclear. In this study, quantitative real-time PCR was carried out to measure the expressions of circ_0002111, microRNAs (miRNAs) and high-mobility group box 1 (HMGB1). Immunohistochemistry assay and western blot were applied for the determination of protein levels. The assays of 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide and thymidine analog 5-ethynyl-2'-deoxyuridine were deployed to assess PTC cell viability and proliferation, respectively. Besides, the capacities of cell apoptosis, invasion and angiogenesis were determined by flow cytometry, transwell and tube formation assays, respectively. Moreover, the interaction between miR-363-3p and circ_0002111 or HMGB1 was confirmed using a dual-luciferase reporter assay. Lastly, we established a xenograft model for the examination of the function of circ_0002111 in vivo. It was found that the expression of circ_0002111 was enhanced in PTC tissues and cells. Silencing circ_0002111 apparently retarded the viability, proliferation, invasion and tube formation, as well as expedited the apoptosis of PTC cells. Besides, circ_0002111 knockdown impeded the growth of the tumor in vivo. For mechanism analysis, circ_0002111 adjusted the expression of HMGB1 by sponge adsorption of miR-363-3p. Moreover, miR-363-3p inhibitor regained the influence of cellular malignant phenotype caused by circ_0002111 knockdown. Additionally, miR-363-3p overexpression impacted the cell functions by targeting HMGB1 in PTC. Thus, silencing circ_0002111 constrained the progression of PTC by the miR-363-3p/HMGB1 axis, which perhaps provided a novel idea of the therapeutic in PTC.

Long non-coding RNA nuclear enriched abundant transcript 1 (NEAT1) modulates inhibitor of DNA binding 1 (ID1) to facilitate papillary thyroid carcinoma development by sponging microRNA-524-5p.

Long non-coding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) exerts a pro-oncogenic role in several cancers, whereas its underlying regulatory mechanism in papillary thyroid carcinoma (PTC) progression remains unknown. This research mainly explored the roles of NEAT1 in PTC development. Quantitative real-time polymerase-chain reaction (qRT-PCR) was applied to measure NEAT1, miR-524-5p, and inhibitor of DNA binding 1 (ID1) expression in PTC tissues and cells. Western blot was conducted for detecting the protein levels. MTT, transwell, and flow cytometry assays were applied to assess cell proliferation, metastasis, and apoptosis in PTC cells in vitro. The PTC xenograft tumor model was used for investigating the role of NEAT1 in vivo. Dual-luciferase reporter assay was utilized for confirming the interaction between miR-524-5p and NEAT1 or ID1. In PTC tissues and cells, NEAT1 was significantly up-regulated. NEAT1 silencing blocked cell proliferation, metastasis, and facilitated apoptosis in vitro and impeded xenograft tumor growth in vivo. Bioinformatics prediction revealed the existence of binding sites between NEAT1 and miR-524-5p. Besides, ID1 was confirmed as a direct target to miR-524-5p, and the enhancement of ID1 reversed the regulation of miR-524-5p upregulation on cell progression. In addition, NEAT1 promoted PTC development by regulating ID1 expression via sponging miR-524-5p in PTC. In summary, we demonstrate that NEAT1 advanced the process of PTC by miR-524-5p/ID1 axis, which may enhance our comprehension of PTC pathogenesis.

The Cycas genome and the early evolution of seed plants.

Cycads represent one of the most ancient lineages of living seed plants. Identifying genomic features uniquely shared by cycads and other extant seed plants, but not non-seed-producing plants, may shed light on the origin of key innovations, as well as the early diversification of seed plants. Here, we report the 10.5-Gb reference genome of Cycas panzhihuaensis, complemented by the transcriptomes of 339 cycad species. Nuclear and plastid phylogenomic analyses strongly suggest that cycads and Ginkgo form a clade sister to all other living gymnosperms, in contrast to mitochondrial data, which place cycads alone in this position. We found evidence for an ancient whole-genome duplication in the common ancestor of extant gymnosperms. The Cycas genome contains four homologues of the fitD gene family that were likely acquired via horizontal gene transfer from fungi, and these genes confer herbivore resistance in cycads. The male-specific region of the Y chromosome of C. panzhihuaensis contains a MADS-box transcription factor expressed exclusively in male cones that is similar to a system reported in Ginkgo, suggesting that a sex determination mechanism controlled by MADS-box genes may have originated in the common ancestor of cycads and Ginkgo. The C. panzhihuaensis genome provides an important new resource of broad utility for biologists.

Enhancement of denitrification in biofilters by immobilized biochar under low-temperature stress.

Efficient removal of nitrate under low temperature is challenging because of the reduction of the microbial activity. This study successfully explored the promotion on the performance of denitrification utilizing the immobilized biochar in biofilters under low temperature (6 ± 2 °C). The results showed that the immobilized biochar increased the denitrification rate by 76.8% and decreased the nitrous oxide emissions by 82.5%. Mechanistic studies revealed that the immobilized biochar increased the activities of the denitrifying enzymes and three enzymes involved in glycolysis. Furthermore, the immobilized biochar elevated the activity of the electron transport system by 31.8%. Finally, structural equation model explained that the increase of nitrate reductase activity was a crucial factor to enhance the total nitrogen removal efficiency in biofilters with immobilized biochar. Overall, the use of immobilized biochar can be a novel strategy to enhance nitrogen removal and reduce greenhouse gas emissions in biofilters under low temperature.

A fluorescence microplate assay based on molecularly imprinted silica coated quantum dot optosensing materials for the separation and detection of okadaic acid in shellfish.

Molecularly imprinted polymers (MIPs) are attracting substantial interest as artificial plastic antibodies because of their biometric capability for targeting small molecules. In this study, molecularly imprinted silica material-coated quantum dots (MIS-QDs) with selective recognition capability to okadaic acid (OA) were developed and characterized. The synthesized MIS-QDs with specific imprinting cavities exhibited excellent recognition capability similar to those of biological antibodies and high fluorescence (FL) quenching selectivity for OA. Furthermore, the MIS-QDs with unsaturated bonds were immobilized onto the surface of 96-well microplates by cold plasma-induced grafting. A novel direct competitive microplate assay strategy was then proposed. The FL quenching properties of the developed microplate assay showed an excellent linear relationship with OA in the range of 10.0-100.0 µg/kg with a correlation coefficient of 0.9961. The limit of detection for OA was 0.25 µg/kg in the shellfish samples. The mean quantitative recoveries were 92.5%-101.0% and 92.9%-101.3%, with relative standard deviations of <7.7% and 7.6% for pure solvents and purified shellfish samples, respectively. The established microplate assay strategy can be used as a rapid and high-throughput method for analyzing OA marine toxins in biological samples.

CO2 Leakage Behaviors in Typical Caprock-Aquifer System during Geological Storage Process.

In this study, a 3D reactive flow simulation model is built to simulate the leakage processes though assumed leakage channels. The geochemical reactions are coupled with fluid flow simulation in this model with consideration of reservoir minerals calcite, kaolinite, and anorthite. As an essential trigger for geochemical reactions, changes in pH value are investigated during and after the CO2 injection process. By comparing CO2 migration with/without geochemical reactions, the influence of geochemical processes on CO2 leakage is illustrated. The leakage behaviors through leakage channels with different permeabilities are evaluated. Influence of reservoir temperature on CO2 leakage is also exhibited. Furthermore, the effects of the distance between the injection well and leakage zone on the leakage potential are studied. The results indicate that the geochemical reactions have impact on the leakage processes, which can decrease the leakage level with the presence of geochemical reactions. The region of low pH enlarges with continuous injection of CO2. Hence, monitoring changes in pH can reflect the migration of CO2, which can provide an alert for CO2 leakage. The occurrence of the leakage phenomenon is postponed with increasing the distance between the CO2 injection well and the leakage channel. However, the leakage level tends to be consistent with injecting more CO2. The CO2 leakage risk can be reduced through the leakage channels with lower permeability. With the presence of higher reservoir temperatures, the leakage risk can be improved. These results can provide references for the application of monitoring methods and prediction of CO2 front associated with geochemical processes.

Characterization and application of molecularly imprinted polymer-coated quantum dots for sensitive fluorescent determination of diethylstilbestrol in water samples.

Molecularly imprinted silica layers coated to quantum dots (MIP-QDs) were successfully fabricated and applied as the fluorescence probe for highly selective and sensitive determination of diethylstilbestrol (DES). Scanning electron microscopy, Transmission electron microscopy, and Fourier transform infrared spectroscopy indicated successful grafting of molecularly imprinted silica layers onto the surface of QDs. Furthermore, the fluorescence assay based on the MIP-QDs showed excellent selectivity and fluorescence quenching capability in optimal conditions and a good linear relationship was obtained in the range of 2.0 × 10-4-10.0 mg/L with a correlation coefficient of 0.9980. The limit of detection of 5.9 × 10-5 mg/L was acquired. Good recoveries ranging from 95.5% to 107.5% were achieved with relative standard deviations (RSD) below 8.4% for seawater and river water samples. The fabricated MIP-QDs were successfully employed as the recognition and response element of an microtitration 96-well fluorescence detection system. Good recoveries ranging from 82.9% to 102.0% with RSDs below 10.0% were obtained for seawater and river water samples. Results demonstrate that simple, rapid, and sensitive DES determination method based on MIP-QDs can be successfully applied to DES residue detection in seawater and river water samples.

Mechanism study of cyfluthrin biodegradation by Photobacterium ganghwense with comparative metabolomics.

A high-efficiency pyrethroid-degrading bacterium, Photobacterium ganghwense strain 6046 (PGS6046), was first isolated from an offshore seawater environment. Metabolomics method was used to investigate the biotransformation pathway of PGS6046 to cyfluthrin wherein 156 metabolites were identified. The growth rates of the PGS6046 cultivated in nourishing media were much higher than those cultivated in seawater, regardless of the presence of cyfluthrin. Statistical analyses revealed that the metabolic profile of PGS6046 was associated with the culture medium, the presence of cyfluthrin, and culture time. The PGS6046 cultivated in a nourishing medium was characterized by higher levels of amino acids, a lower abundance of intermediates in the tricarboxylic acid cycle, and the presence of some fatty acids than those cultivated in seawater. The effects of cyfluthrin on PGS6046 metabolism varied based on the culture medium, whereas the cyanoalanine levels increased under both culture conditions. Culture time significantly affected the metabolism of amino acids and carbohydrates in PGS6046. The present study revealed the metabolic characteristics of PGS6046 under different culture conditions and will further facilitate the exploration of the fundamental questions regarding PGS6046 and its potential applications in environmental bioremediation.

Determination of lipophilic marine toxins in fresh and processed shellfish using modified QuEChERS and ultra-high-performance liquid chromatography-tandem mass spectrometry.

A simple QuEChERS method coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed to improve the extraction efficiency of lipophilic marine toxins (yessotoxins, dinophysistoxins, okadaic acid, azazspiracids, and spirolides) in fresh and processed shellfish products. The proposed method included freezing and dispersive solid-phase extraction with graphene oxide as the sorbent to clean complex matrices containing lipids (e.g., free fatty acids) and pigments. Quantification was performed using matrix-matched calibration curves. Recoveries were 85%-117.4% and the relative standard deviation for precision was less than 10% for marine toxins in fresh and processed shellfish products. The limits of detection (signal-to-noise = 3) and quantification (signal-to-noise = 10) were 0.10-1.47 and 0.32-4.92 µg/kg, respectively. The validated QuEChERS method, coupled with UPLC-MS/MS, was applied successfully to determine lipophilic marine toxins in fresh and processed shellfish samples.

An Electrochemiluminescence Sensor Based on Nafion/Magnetic Fe3O4 Nanocrystals Modified Electrode for the Determination of Bisphenol A in Environmental Water Samples.

The well-dispersive and superparamagnetic Fe3O4-nanocrystals (Fe3O4-NCs) which could significantly enhance the anodic electrochemiluminescence (ECL) behavior of luminol, were synthesized in this study. Compared to ZnS, ZnSe, CdS and CdTe nanoparticles, the strongest anodic ECL signals were obtained at +1.6 V on the Fe3O4-NCs coated glassy carbon electrode. The ECL spectra revealed that the strong ECL resonance energy transfer occurred between luminol and Fe3O4-NCs. Furthermore, under the optimized ECL experimental conditions, such as the amount of Fe3O4-NCs, the concentration of luminol and the pH of supporting electrolyte, BPA exhibited a stronger distinct ECL quenching effect than its structural analogs and a highly selective and sensitive ECL sensor for the determination of bisphenol A (BPA) was developed based on the Fe3O4-NCs. A good linear relationship was found between the ECL intensity and the increased BPA concentration within 0.01⁻5.0 mg/L, with a correlation coefficient of 0.9972. The detection limit was 0.66 × 10-3 mg/L. Good recoveries between 96.0% and 105.0% with a relative standard deviation of less than 4.8% were obtained in real water samples. The proposed ECL sensor can be successfully employed to BPA detection in environmental aqueous samples.