Environmental Science: Nano最新文献

Oilseed rape (Brassica napus L.) cultivation increasingly faces challenges from arsenic (As) contamination, which disrupts plant metabolism through oxidative stress and antioxidant enzyme inhibition. This study investigated the potential of manganese nanoparticles (MnNPs) to alleviate As toxicity across five genetically distinct B. napus cultivars under hydroponic conditions. Plants were exposed to varying concentrations of As (0, 100, and 200 μM) and MnNPs (0, 50, and 100 μM) to evaluate treatment efficacy. Results demonstrated that As stress (200 μM) severely reduced leaf fresh weight (43.88–77.57%), root fresh weight (69.35–91.2%), and photosynthetic efficiency while significantly increasing reactive oxygen species (ROS) accumulation across all cultivars. Conversely, the application of 100 μM MnNPs substantially ameliorated these effects, increasing leaf fresh weight by 25.26–70.65%, improving photosynthetic rate by 61.94–77.27%, and restoring stomatal conductance by 43.48–58.83% compared to As-only treatment. Additionally, MnNPs significantly reduced oxidative stress markers in both leaf and root tissues while upregulating antioxidant enzyme activities beyond levels induced by As stress alone. Metabolic analysis complemented these physiological findings, revealing variety-specific profiles with ZD 622 exhibiting high hexenol acetates, while the combined MnNPs + As treatment induced the strongest metabolic response, suggesting synergistic stress defense effects. Notably, cultivars exhibited distinct genotype variations, with ZD 635 and ZY 758 demonstrating superior As tolerance following MnNP treatment, whereas ZD 622 showed the least tolerance. These findings collectively highlight MnNPs' effectiveness in enhancing B. napus productivity in As-contaminated environments by improving stress tolerance mechanisms, underscoring their potential as a valuable nano-agronomic intervention.

This research involved a comprehensive multisystemic evaluation of the biotoxicity of three tracers (carbon quantum dots synthesized from citric acid and ethylenediamine “N-CQD”, commercial cadmium-tellurium quantum dots “CdTe-QD”, and a conventional tracer based on fluorinated benzoic acid derivatives “SB-tracer”). Biotoxicity was assessed at three organizational levels: DNA, cellular, and multicellular eukaryotic system, using the comet assay and chromosomal aberration tests, cytotoxicity assays, and plant growth profiling, respectively. The results revealed significant DNA damage induced by CdTe-QD and SB-tracer, with olive tail moment (a measure of DNA degradation) values up to 15 times higher than those observed for N-CQD in the comet assay. Cytotoxicity revealed an half maximal inhibitory concentration (IC₅₀) > 1000 mg L⁻¹ for N-CQD, 7.35 mg L⁻¹ for CdTe-QD, and 600.06 mg L⁻¹ for SB-tracer, classifying the samples as non-cytotoxic, cytotoxic, and moderately cytotoxic, respectively. However, the chromosomal aberration results for SB-tracer revealed its lethality by inhibiting the lymphocyte proliferation required for the test. Melon and sunflower seed sprouts were employed as multicellular eukaryotic models for toxicity evaluation at higher organizational levels, and it was observed that SB-tracer has a deleterious effect on germination, while N-CQD increased sprout biomass by up to 19 times compared to water irrigation, a result attributed to their positive effect on photosynthetic mechanisms. Finally, the non-toxic and protective effects of N-CQD can be attributed to their high ORAC (oxygen radical absorbance capacity) value considered in this research, which is associated with the prevention of damage to key biomolecules such as DNA and the promotion of cell growth. These results highlight the feasibility and potential use of CQDs as a safe alternative for both the environment and health, with the potential to substitute substances conventionally employed by different industries as multipurpose tracers. To the best of our knowledge, this is the first study to comprehensively evaluate the biotoxicity of QDs at multiple biological organization levels.

With the increasing release of nanomaterials into soil ecosystems, the intensity of combined exposure to nanomaterials and metalloids/heavy metals are rising, highlighting the urgent need to understand their joint toxicological effects of nanomaterials and metalloids/heavy metals. In this study, the ecotoxicological impacts of the co-exposure of molybdenum disulfide nanomaterials (MoS₂ NMs) and the metalloid arsenic (As) in soil are explored. Specifically, a pot experiment was conducted to investigate the toxic effects of combined exposure to As (25, 50, and 100 mg kg⁻¹ soil) and MoS₂ NMs (30 mg kg⁻¹ soil) on earthworms. Key parameters including earthworm growth, bioconcentration, physiological and biochemical responses, and gut microbial metabolism were assessed. Soil and earthworm samples were collected on the days 7, 14, and 28 post-treatment. The results revealed that the co-exposure of MoS₂ NMs and As increased the As accumulation in earthworms by 16.3%, 26.7%, and 12.4%, and reduced their body weights by 39.5%, 34.9%, and 28.1%, respectively, compared to the single exposure of As. This co-exposure aggravated pathological damage, elevated oxidative stress, and significantly increased the integrated biomarker response index. Furthermore, it disrupted the balance of gut flora and metabolic pathways in earthworms and enhanced their toxicity. This study provides new insights for evaluating the ecological and health risks associated with the simultaneous presence of nanomaterials and metalloids/heavy metals in soil environments.

The increasing release of antimony (Sb) into water environments due to anthropogenic activities poses significant ecological risks. This study developed a novel hybrid material, zeolitic imidazolate framework-8-iron nanoparticles (ZIF-8-Fe NPs), which demonstrates a synergistic adsorption–oxidation mechanism for the efficient removal of Sb(III) from aqueous solutions. Major findings reveal that at an initial Sb(III) concentration of 1 mg L⁻¹, ZIF-8-Fe NPs achieved a 73.3% removal efficiency within three hours through the dual processes of direct adsorption and oxidation of Sb(III) to Sb(V). Scanning electron microscopy–energy dispersive spectrometry (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) revealed that the removal mechanism involved both direct adsorption of Sb(III) by ZIF-8-Fe NPs and oxidation of Sb(III) to Sb(V), with two distinct morphologies of Sb adsorbed on the surface. The formation of covalent bonds (Zn–OH–Sb and Fe–O–Sb) was identified as the key factor in the removal of both Sb(III) and Sb(V) from aqueous solutions. The adsorption process conformed to the Langmuir adsorption isotherm and pseudo-second-order kinetics, with correlation coefficients (R²) of 0.959 and 0.999, respectively. The proposed mechanism suggests that the formation of Zn–OH–Sb and Fe–O–Sb covalent bonds plays a crucial role in Sb(III) removal. Significantly, ZIF-8-Fe NPs achieved removal efficiencies of 91.5% and 94.8% for Sb(III) at environmentally relevant concentrations of 100 μg L⁻¹ and 20 μg L⁻¹, respectively, in actual mining wastewater, demonstrating their practical applicability. This study establishes that ZIF-8-Fe NPs constitute an effective nanomaterial with significant potential for Sb(III) remediation in wastewater.

Sustainable photocatalysis has emerged as a promising approach for environmental remediation by combining efficiency with green chemistry principles. In this study, Ca-TiO₂ photocatalytic platforms were developed using cellulose paper as a substrate, calcium sourced directly from eggshell biowaste, and a sustainable microwave-assisted synthesis approach. A novel functionalization of the Whatman paper preserved its structural integrity at temperatures above 200 °C, enabling the direct growth of TiO₂ nanomaterials on paper substrate without any post-synthesis treatment. Incorporation of bio-derived Ca²⁺ modified the TiO₂ structure, inducing structural defects that included lattice distortions, voids, and surface step sites, modifying optical absorption, and enhancing surface hydroxylation. The resulting Ca-TiO₂ paper-based platforms efficiently degraded tetracycline, achieving over 80% removal under solar irradiation in 150 minutes, corresponding to a photodegradation rate 1.3 times higher than that of pure TiO₂. Reusability and ecotoxicity tests confirmed their stability and safety for long-term environmental applications. By integrating waste valorization, green synthesis, and structural modifications, this work demonstrates a sustainable and scalable strategy for producing high-performance photocatalytic platforms, aligning with circular economy principles and offering potential solutions for global water pollution challenges.

The co-assembly of humic acid (HA)-coated maghemite nanoparticles (H-GFeNPs) and bovine serum albumin (BSA)-modified maghemite nanoparticles (B-GFeNPs) and sequestration of NO₃⁻ within the colloidal crystals were investigated. The π–π interaction between aromatic moieties of the adsorbed BSA and HA controlled the co-assembly process. The 1 : 1 binary mixture of H-GFeNPs and B-GFeNPs at pH 4 showed screw dislocation-driven growth of colloidal crystals, especially at higher concentrations of NO₃⁻. But, at pH 7, the binary mixture in the presence of NO₃⁻ produced spherical dendritic nanostructures and hierarchical growth of dendrites. However, at higher levels of NO₃⁻, the binary mixture produced a 2D cubic lattice and rock salt-like 3D colloidal crystals. In addition, we also detected the growth of dendrites, ubiquitous in rock salt-type crystal growth, specifically in an unsaturated environment. The binding of NO₃⁻ to the hydrophobic and positively charged residues of the protein, supplemented by the loss of α-helix and the reduced radius of gyration (R_g), possibly favored crystal growth. Signatures of the NO₃⁻ specific Raman bands within the colloidal crystals discerned the sequestration of the highly mobile contaminant ion within the crystalline domain, therefore potentially diminishing the atmospheric emission of high global warming potential (GWP) oxides of N produced via denitrification.

Antibiotic contamination represents a pressing environmental crisis affecting aquatic ecosystems globally, a challenge that climate change only intensifies. Key culprits of this pollution include pharmaceutical discharges, agricultural runoff, and improper waste disposal. These antibiotics persist in our water systems due to their stable chemical structures, while climate-related factors like rising temperatures and extreme weather can exacerbate their impact. The accumulation of these substances poses significant threats to aquatic life, human health, and the broader environment, as they facilitate the alarming spread of antimicrobial resistance among microorganisms. Unfortunately, traditional water treatment methods remain largely ineffective against these stubborn pollutants. In response to this growing issue, green nanotechnology emerges as a promising and sustainable solution. By harnessing plant extracts, microbes, and agricultural waste for the synthesis of nanoparticles, this approach minimizes environmental harm while effectively addressing contamination. Metal oxide nanoparticles, carbon-based materials, and biopolymeric nanomaterials have proven to be highly efficient in eliminating antibiotics through processes such as adsorption, photodegradation, and redox reactions. However, the effectiveness and applicability of these nanoparticles under varying climate conditions warrant further exploration. This review highlights the transformative potential of green nanotechnology for safe and sustainable water remediation. It underscores recent advancements in eco-friendly nanomaterials, elucidating their removal mechanisms, environmental behavior, and the critical need for climate-resilient, safe-by-design strategies. To combat antibiotic pollution effectively amid shifting climatic conditions, we must investigate green nanotechnology for future water treatment practices. This proactive approach not only safeguards our water systems but also ensures a healthier future for both aquatic ecosystems and human communities.

Access to clean drinking water remains a critical global health issue, with over 2 billion people lacking access to safely managed water. Among the contaminants of concern, heavy metals (particularly arsenic) pose significant risks due to their persistence and toxicity. Long-term exposure to arsenic (As³⁺), especially at concentrations exceeding the World Health Organisation's (WHO) guideline of 10 μg L⁻¹, has been linked to severe health conditions, including cancer, dermatological issues, and cognitive impairments. Traditional laboratory-based approaches offer high sensitivity and selectivity but are expensive, time-consuming, and require skilled personnel, making them impractical for in-the-field use. In recent years, electrochemical methods, particularly using screen-printed electrodes (SPEs), have emerged as a promising alternative for As³⁺ detection, the most toxic form. SPEs offer a compact, cost-effective, and portable solution, enabling real-time, on-site monitoring of arsenic levels in water. This review systematically explores recent advancements in SPEs for the detection of As³⁺, with a focus on electrode modifications aimed at enhancing sensitivity and selectivity. We highlight techniques involving the integration of precious metals, biosensors, and carbon-based materials, all of which contribute to improved (lower) detection limits and wide sensing ranges. Practical applications in environmental monitoring (particularly in remote or resource-limited settings) are also discussed, offering a scalable and efficient solution for arsenic detection; SPEs have the potential to revolutionise water quality assessment and supporting global public health initiatives.

Detecting glyphosate (Gly), a widely used herbicide in agricultural practice worldwide, is crucial due to its environmental impact and potential health risks. This study presents a colorimetric sensor based on gold nanoparticles (AuNPs) functionalized with cysteamine (AuNPs + Cys) for Gly-sensitive and selective detection. The AuNPs were synthesized using the Turkevich method and characterized using ultraviolet-visible spectroscopy (UV-vis), dynamic light scattering, X-ray diffraction spectroscopy, and scanning electron microscopy. The AuNPs display a localized surface plasmon resonance peak at a 520 nm wavelength and have an average size distribution of 23 nm with good dispersion. The AuNPs + Cys exhibit unique optical properties, allowing for visible color changes in response to varying concentrations of Gly. The detection mechanism relies on the interaction between Gly and the Cys on the nanoparticle surface, which induces changes in the aggregation state of the AuNPs, leading to a shift in the UV-vis absorption spectrum. The sensor was tested at a maximum concentration of 100 ppm Gly, with a detection limit of 1.42 ppm and a distinct color change easily visible to the naked eye. To evaluate the sensor's selectivity, assays were conducted in a soil matrix. Glufosinate was employed as a complementary analyte, and the sensor exhibited a clear differentiation, thus achieving selective detection between the herbicides. The developed AuNPs + Cys sensor offers a simple, cost-effective, and efficient method for Gly detection, with potential applications in environmental monitoring and agricultural practices.