Environmental Science: Nano最新文献

Chilo suppressalis is a major pest that severely impacts rice production in China. However, the widespread use of insecticides has resulted in the development of resistance in C. suppressalis. The advancement of nanotechnology offers promising prospects for enhancing insecticide formulations and improving their efficacy. This study designed a pH-responsive release system composed of γ-PGA and chitosan (CS) loaded with chlorantraniliprole (CLAP). The synthesized CLAP-loaded nanoparticles had an average particle size of approximately 39.67 nm and a loading efficiency of 38.87%. Under a pH of 8.5, 64.4% of the pesticide was released within 120 hours. The CLAP@CS/γ-PGA formulation, after loading, exhibited a significant synergistic insecticidal effect, with bioassay results showing an 82.2% mortality rate of C. suppressalis six days post-treatment. Tests of metabolic genes and enzyme activities showed that CLAP@CS/γ-PGA rendered C. suppressalis more sensitive to insecticides by inhibiting the activities of P450 and by decreasing the expression of CYP9A68. CLAP@CS/γ-PGA also demonstrated favorable transport properties within C. suppressalis and rice plants, and due to the encapsulation by the nanoparticle carrier, it reduced toxicity to zebrafish. In summary, the system we investigated not only meets the needs of pest management but also enhances the utilization of pesticides.

The combination of a semiconductor photocatalyst mediated photocatalytic reaction and persulfate activation is considered as a promising way to achieve efficient degradation of recalcitrant organic pollutants in water. Here, a series of Cu-doped BiO_2−x nanosheets were successfully manufactured and used to activate peroxymonosulfate (PMS) for the removal of ciprofloxacin (CIP). Here, with the help of visible light, the optimal Cu-doped BiO_2−x nanosheets (CBO-1) activating PMS for the removal of CIP have a degradation rate 4.64 times more than that of BiO_2−x. Photo/electro-chemical characterization and theoretical calculations have demonstrated that the introduction of Cu can also increase the electron density near the Fermi level, which accelerates the separation and movement of photo-generated carriers of photocatalysts, and then reduces the activation energy barrier of PMS and improves its utilization efficiency. Besides, the electron-poor Cu center was prone to form Cu ligands with CIP and enhance the reduction of Cu(II) to accelerate the activation of PMS. Therefore, this work proposes a method for synthesizing efficient semiconductor photocatalysts for activating PMS, providing a valuable reference for the efficient mineralization of recalcitrant contaminants in water.

A rational design of water-stable and high-efficiency MOF-based electrocatalysts for achieving durable sensitive electrochemical sensors for pollution detection remains a great challenge. Herein, water-stable Co²⁺-doped Cu²⁺ and 1,3,5-benzene tricarboxylic coordination polymers (Cu–BTC@Co) were designed to construct a sensitive and durable electrochemical sensor for simultaneously detecting multiple hazardous phenols. Combining the Mulliken charges of H₂O and BTC, the mechanism for the water stability of Cu–BTC@Co was discussed. Intermolecular force (Cu–BTC and Cu–H₂O) and intramolecular force (π–π bond and COO–H₂O hydrogen bond) made Cu²⁺ coordination to BTC much stronger than water; thus, Cu–BTC@Co with strong stability in a water environment was achieved. Moreover, doping Co²⁺ into Cu–BTC not only improves the electron transfer efficiency of Cu–BTC but also enhances the catalytical efficiency of Cu–BTC. Combining the high-efficiency selective catalysis of Cu–BTC@Co and oxidation potential difference among multiple phenols, the Cu–BTC@Co sensor can achieve simultaneous, quantitative and qualitative detection of multiple phenols with good multicycle sensing performance. This study clarifies the mechanism of synthesizing water-stable MOFs and promotes the application of MOF-based sensors in the quantitative analysis of water pollutants.

Pesticides and their metabolites threaten the environment and human health even at low concentrations. Therefore, the development of sensors to track such substances is crucial. Nanoparticle-based sensors have been widely used recently as a possible substitute analytical tool for traditional pesticide detection techniques. Artificial enzymes, also known as enzyme mimics or nanozymes, are gaining attention due to their innate ability to overcome the limitations of natural enzymes and their efficacy to be sufficient for upcoming advancements in treatments and diagnostics. Nanozyme-based assays may enable organophosphate pesticide detection without relying on the natural cholinesterase enzymes while retaining similar or higher sensitivity at a lower cost. Therefore, the present work investigates the acetylthiocholine (ATCH) hydrolyzing ability of gold nanorods (GNRs) through colorimetric, computational, and electrochemical methods. The GNRs were observed to intrinsically exhibit ATCH hydrolyzing ability, like acetylcholinesterase (AChE). Further, the effect of different organophosphates (OPs) (malathion, methyl parathion, chlorpyrifos, parathion, and dichlorvos) on the ATCH hydrolyzing ability of nanostructures was studied using an electrochemical approach. Their activity was significantly quenched in the presence of malathion and methyl parathion as compared to other OPs. The increasing order of OPs' inhibitory effect was malathion > methyl parathion > dichlorvos > chlorpyrifos > parathion. It was observed that inhibition was proportional to the increasing concentration of OPs, and the linear range of detection was 0.0005–200.0 μg mL⁻¹, with a limit of detection (LOD) of 8.1 pg mL⁻¹ and 30.2 pg mL⁻¹, respectively, for malathion and methyl parathion. Validation of river water samples spiked with different concentrations of malathion shows good recovery in the range of 100–110%.

Plants are widely present in soil ecosystems, and plant root exudates are therefore considered as an important factor that could affect the fate and transport of microplastics (MPs). The effect of quartz sand surface-bound root exudates of rice (long-grained rice) was used to explore its influence on both PS and PET MPs in porous media. 0.51 μm PS MPs and 1.1 μm PS MPs, and 1 μm PET MPs were investigated under 0.1–10 mM NaCl and 0.1–1 mM CaCl₂ solutions. The sand surface-bound root exudates were found to decrease the transport of both PS and PET MPs, with the most obvious difference in the intermediate ionic strengths in both NaCl and CaCl₂ solutions. By performing the column experiment after the removal of sand surface-bound root exudates, it was verified that the role of physical space occupation by the root was not the factor driving the inhibited transport of PS and PET MPs. Further investigations revealed that the surface properties of quartz sand altered by the presence of root exudates was the main factor responsible for the decreased transport of PS and PET MPs. The zeta potentials, excitation–emission–matrix (EEM) spectra, and the components of the root exudates were determined. It was observed that microbial by-product-like substances, fluvic acid-like substances and aromatic protein were the major components of the root exudates. The results indicated that the electrostatic repulsive forces between MPs and quartz sand were expected to be lower in the presence of sand surface bound-root exudates as predicted by the DLVO theory. The findings of this study are essential to shine light on the knowledge of the fate and transport of plastic particles in soil systems with ubiquitous plants.

Micro- and nanoplastics are emerging pollutants that have attracted significant attention due to their potential to concentrate and transport coexisting organic pollutants in aquatic environments. Fluorinated liquid-crystal monomers (FLCMs) have also emerged as contaminants of concern, given their frequent occurrence, potential toxic effects, and propensity to co-occur with plastics in the environment. However, the influence of plastics on the environmental fate of FLCMs remains unclear yet. To address this knowledge gap, we investigated the accumulation of a key FLCM, 4-cyano-3-fluorophenyl 4-ethylbenzoate (CEB-F), on three common plastics, and examined the effects of nanoplastics on the phototransformation of CEB-F and its acute toxicity to Daphnia magna (D. magna). Our findings revealed that the adsorption capacity of CEB-F on different plastic materials followed the order: polystyrene (PS) < mixed cellulose ester (MCE) < polyamide (PA). The adsorption processes of CEB-F on the three plastics aligned more closely with the pseudo-first-order kinetic model and the Langmuir isotherm model, suggesting that the adsorption is primarily governed by physical diffusion. Theoretical calculations indicated that the adsorption of CEB-F on PS plastics is mainly driven by hydrophobic interactions. Additionally, PS nanoplastics (PSNPs) significantly enhanced the UV degradation of CEB-F, although the types of degradation intermediates did not change substantially, suggesting a limited impact on the degradation process and mechanism. Acute toxicity tests showed that PSNPs increased the toxicity of CEB-F to D. magna at lower concentrations, while the toxicity was reduced at higher concentrations. The obtained findings are of great significance to unraveling the plastic-mediated environmental fate and aquatic toxicity of FLCMs in natural waters.

A novel magnetic nanocomposite was successfully synthesized using date palm mesh fiber waste as a sustainable substrate. This green and cost-effective approach produced a nanocomposite characterized by various techniques. The BET-specific surface area and total pore volume of the magnetic nanocomposite were 19.46 m² g⁻¹ and 0.099 m³ g⁻¹, respectively. These values were much higher than those of the raw substrate. The synthesized magnetic nanocomposite was tested as an adsorbent for removing methylene blue (MB organic pollutant) and potassium permanganate (MnO₄⁻ inorganic pollutant) from water. Optimal conditions (adsorbent dosage, pH, temperature, equilibrium time) for removing MB and MnO₄⁻ from water using the magnetic nanocomposite were determined. Under these conditions, the nanocomposite exhibited excellent removal efficiency for MB and MnO₄⁻ with ∼95% and 99%, respectively. The experimental data were best fitted by the Langmuir model and the pseudo-second-order kinetic model for MB and MnO₄⁻ with the highest sorption capabilities of 10.77 and 58.48 mg g⁻¹, respectively. The applicability of the nanocomposite was examined in various real-water samples and satisfactory results were obtained. The magnetic biosorbent showed good reusability, maintaining 81.3% removal efficiency for MB after eleven consecutive adsorption–desorption cycles using ethanol. It is expected that this high-capacity, recyclable magnetic adsorbent can potentially offer a promising, facile, cost-efficient, and eco-friendly route to pollutant water treatment.

Membranes have become a basis in tackling the global challenge of freshwater scarcity, notably in the fields of desalination and water purification. MXenes, distinguished by their notable high aspect ratio, extensive surface area, robust mechanical strength, and enduring chemical resilience, have emerged as highly promising materials for membrane development. Recent progress in the research and application of MXene membranes, especially in the areas of water desalination and treatment, marks a significant leap forward in this domain. This study conducts an exhaustive analysis of the state-of-the-art developments in the creation and enhancement of MXene-based membranes. It delves into their application in various desalination processes, including membrane-based desalination and solar-driven interfacial steam generation, alongside their use in water purification. This analysis sheds light on their efficacy in desalination processes, in addition to evaluating their antimicrobial properties and salt rejection efficiency. Moreover, the review provides an in-depth examination of the mechanics behind MXene membranes and assesses their overall impact, pinpointing both the current opportunities they present and the challenges they face. The primary goal of this discussion is to enrich the collective understanding of MXene membrane technology and to drive continuous improvement and innovation in this area. By doing so, it aims to contribute to the advancement of sustainable solutions to water scarcity through the development of more efficient and effective membrane technologies.

Airborne nanoparticles (NPs) are particles with a diameter smaller than 100 nm, which can significantly influence global climate, regional air quality, and human health. The interactions between airborne nanoparticles and atmospheric ions are ubiquitous, which also condition the charge state of nanoparticles. To deepen our understanding of nanoparticles in different regions of China and explore their interactions with air ions, we conducted a one-year measurement of airborne nanoparticle number size distributions in six Chinese cities. Six homemade bipolar scanning mobility particle sizers were applied to scan both positively and negatively charged nanoparticles. The annual average number concentrations of nanoparticles (N_NPs) are 5880 ± 3140 # cm⁻³ (Beijing), 6280 ± 2910 # cm⁻³ (Shanghai), and 5440 ± 3370 # cm⁻³ (Wuhan) in the three urban sites, and 5320 ± 3440 # cm⁻³ (Shenzhen), 3440 ± 2370 # cm⁻³ (Zhuhai) and 2440 ± 1870 # cm⁻³ (Kunming) in the three suburban sites. N_NPs account for 65.6%–80.4% of the total particle number concentration in the six cities. Besides, N_NPs contributed by new particle formation in suburban areas are comparable to or even higher than those in urban areas. In Beijing and Shanghai, N_NPs decreased by 55.2% and 66.4% from 2013 to 2023, respectively. Ion mobility, composition, and concentration are the parameters governing the charge state of nanoparticles. In Beijing, we found that the ion mobility distribution and nanoparticle charge state vary at the same time, and the composition of negative cluster ions are mainly composed of inorganic nitrogen-containing ions, inorganic sulfur-containing ions, and organic ions.

Drought is a global issue causing severe reductions in crop yields. The use of nanobiotechnology to increase plant resistance to drought is widely reported. However, the mechanisms underlying nanomaterial improvement of crop drought tolerance are not well understood. Herein, we reported that poly(acrylic) acid coated manganese oxide (Mn₃O₄) nanoparticles (PMO, 5.43 nm, −31.6 mV) increase cotton fresh weight (74.9%) under drought stress relative to controls by catalytically scavenging ROS and modulating stomatal aperture. PMO treated cotton leaves showed significantly lower ROS levels (60–70%) determined by confocal microscopy and biochemical and histochemical staining analysis. Also, plants exposed to PMO experienced less oxidative damage than controls under drought, as indicated by their lower malondialdehyde (MDA) content (2.02 ± 0.15 μmol L⁻¹vs. 3.25 ± 0.27 μmol L⁻¹) and electrolyte leakage rate (31.13% ± 5.51 vs. 64.83% ± 4.29). PMO treated cotton plants also maintained stomatal aperture and had higher photosynthetic performance (160%) under drought stress. Furthermore, we set up a portable monitoring system with low cost which can allow the real-time imaging of stomatal aperture and chlorophyll fluorescence in plants treated with nanomaterials. Overall, our results suggested that PMO could be a biocompatible and scalable tool for improving crop drought tolerance.