Environmental Science: Nano最新文献

Peanut smut, caused by Thecaphora frezii, leads to severe annual yield losses worldwide, particularly in Córdoba, Argentina. The fungicide Thiram (tetramethylthiuram disulfide) is widely used to control this disease, but its low aqueous solubility (∼30 mg L⁻¹) is a major limitation to its application. Nanocarriers could enhance Thiram's solubility and stability, possibly increasing its efficiency in agricultural applications. To test this in our laboratory, Thiram was encapsulated in two different delivery systems: a) zirconium-based MOF-808 nanocrystals (nMOF-808) and b) Tween 80/Span 80 (1 : 1) niosomes. nMOF-808 was able to incorporate up to 2 g of the fungicide per gram of absorbent and keep it colloidally stable in aqueous suspension for one day. On the other hand, in the presence of niosomes, it was possible to dissolve up to 0.1 mM Thiram in a colloidally stable form for approximately one month under appropriate conditions. Both systems proved to be photoprotective for the fungicide and were capable of controlled release of the encapsulated Thiram. The incorporation of Thiram into nMOF-808 could be interpreted according to the Langmuir model and kinetically by the intraparticle diffusion model, which is uncommon in the literature for the adsorption of neutral molecules in MOFs. These laboratory results indicate that the studied nanoplatforms are promising for future field studies aimed at optimizing efficiency and sustainability in the control of peanut smut and other fungal diseases.

Environmental stress conditions such as drought, salinity, and heavy metal toxicity can considerably reduce growth and productivity of plants. Nanotechnology offers efficient solutions to enhance plant growth under stressful environments. Nanoparticles (NPs; 1–100 nm) in the form of plant growth promoters, nanopesticides, and nanofertilizers improve the nutrient use efficiency, stress resistance, and soil cleaning and minimize environmental pollution. Nanoparticles also transform plant–microbe associations through the modulation of rhizosphere microbial populations as well as root exudation, influencing the health of the plant as well as ecosystem services. Their nanoscale size and huge surface area facilitate enhanced physiological action and mobility as well as uptake within plant systems, frequently leading to enhanced growth and yield. However, these same traits can also cause toxicity. Therefore, it is important to carefully consider the NPs' size-dependent effects. This review highlights the significance of particle size in plant–NP interactions, with a particular emphasis on their dual potential to cause toxicity and mitigate environmental stress. This is, to the best of our knowledge, the first thorough evaluation of size-dependent NP effects on plants and related microbes. The significance of creating safe, optimized nanomaterials that provide agronomic advantages with little ecological risk is also highlighted.

Poor conductivity and insufficient structural stability of metal–organic frameworks (MOFs) restrict their use in detecting water pollutants. In this work, a PtCu hydrogel was synthesized to support the Cu-BTC MOF (PtCu@Cu-BTC) by coordinating 1,3,5-benzenetricarboxylic acid (BTC) directly on the surface of the PtCu hydrogel for the sensitive detection of o-sec-butylphenol (osBP). Importantly, the three-dimensional network structure of the PtCu hydrogel serves as a stable scaffold, providing a matrix to load metal ions that chelate with BTC. This approach not only enhances the structural stability of the MOFs but also greatly improves their electrical conductivity, allowing the catalyst to maintain consistent catalytic activity and stability during water pollutant detection. Additionally, the in situ formed Cu-BTC coordination layer increases the specific surface area, creating numerous active sites, and offers functional groups that promote pollutant adsorption, thereby significantly boosting sensor performance. The findings show that the developed biosensor has a strong linear response to osBP concentrations ranging from 3 to 100 μM, with a low detection limit of 0.68 μM. This work offers new insights for designing MOF-based functional materials that combine excellent conductivity with robust structural stability.

This study systematically investigates the efficient degradation of the antibiotic fosfomycin (FOS) by a ferrate/peroxymonosulfate (Fe(VI)/PMS) system and simultaneous phosphate removal via in situ formed ferric nanoparticles. The Fe(VI)/PMS system achieved complete FOS degradation within 10 min, with a pseudo-first-order rate constant (0.25 min⁻¹) significantly higher than that of Fe(VI) alone (0.03 min⁻¹) or Fe(VI)/peroxodisulfate (0.18 min⁻¹). Reactive species including SO₄˙⁻, HO˙, and high-valent iron species (Fe(V)/Fe(IV)) were identified as key contributors, with HO˙ playing a dominant role. Optimal conditions included 200 μM PMS, 100 μM Fe(VI), and pH 5.0–7.0. Natural water matrices (e.g., river water and wastewater effluent) slightly inhibited degradation, while seawater enhanced FOS degradation efficiency. The degradation pathways of FOS involve oxidation, bond cleavage, and coupling reactions, with by-products showing reduced toxicity. Notably, the in situ formed ferric nanoparticles effectively removed released phosphate via co-precipitation, and post-treatment solutions exhibited negligible toxicity towards E. coli. This study highlights the use of Fe(VI)/PMS as a promising strategy for FOS remediation with simultaneous nutrient control.

Ferrihydrite (Fh), a metastable iron(oxyhydr)oxide abundant in soils and sediments, plays a pivotal role in regulating phosphorus bioavailability and contaminant Cr(VI) fate, but its rapid phase transformation to low-reactivity crystalline phases limits its long-term functionality. This study investigated how light (Nd³⁺) and heavy (Y³⁺) rare earth elements (REEs) modulate Fh's phase transformation and Cr(VI)/PO₄³⁻ sequestration. The results showed that LREE Nd³⁺ predominantly adsorbed onto Fh surfaces, forming a protective layer that shielded reactive Fe–OH sites and delayed hydroxyl displacement. In contrast, HREE Y³⁺ underwent isomorphic substitution into Fh's octahedral Fe–O framework, inducing lattice distortion and suppressing acicular goethite crystallization by ca. 26%. Both REEs preserved Fh's metastability, and maintained Fe in the oxidized Fe³⁺ state. In addition, both Nd³⁺ and Y³⁺ integration into hematite during transformation slowed Fh conversion to low-adsorptivity crystalline phases. Consequently, after 30 days of aging, REE-doped Fh exhibited significantly enhanced Cr(VI)/PO₄³⁻ sequestration (q_max,Cr(VI) = 19.39 mg g⁻¹ and q_max,P = 43.33 mg g⁻¹ for Fh–Nd, 24.47 and 64.03 mg g⁻¹ for Fh–Y) compared to pristine Fh (q_max,Cr(VI) = 4.91 and q_max,P = 24.03 mg g⁻¹). These enhancements might be driven by prolonged amorphous Fh persistence, REE–Cr(VI)/PO₄ surface precipitation, and REE–O–Fe ternary binding sites. These findings clarify how REE–Fe coupling regulates Cr(VI)/PO₄³⁻ fates in terrestrial ecosystems and also provide insights for designing REE-modified adsorbents for long-term contaminant/nutrient retention in soils or aquatic systems, where Fh's natural transformation would otherwise compromise such efficacy.

Single-particle measurements are essential for understanding the complex and often subtle interactions of engineered nanoparticles with biological systems. However, the preparation of plastic nanoparticles (PNP) for single-particle experiments has been hindered by challenges in reproducibility and fluorescence functionality. Here, we use a robust and simple method for preparing fluorescently labeled PNPs using a confined impingement jet with dilution (CIJ-D) mixer. We prepared PNPs from polystyrene (PS), polypropylene (PP), polyvinyl chloride (PVC), and polylactic acid (PLA) powders with a narrow particle size distribution (between 50–100 nm) and incorporated Nile red (NR) dye into these particles. These PNPs exhibit colloidal stability, uniform fluorescence intensity, and compatibility with single particle tracking measurements. To demonstrate the applicability of our approach, we tracked the interactions of individual PNP with lipid bilayer surfaces composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and cholesterol. Using super-resolution diffusion analysis (fluorescence correlation spectroscopy super-resolution optical fluctuation; fcsSOFI), we characterized the nanoscale diffusion and interaction dynamics of PNPs on the lipid bilayer surface. While electrostatic interactions play a major role in PNP transport dynamics on the bilayer, cholesterol induces slower surface diffusion. Our method provides an easy solution to prepare model PNP systems and study the PNP-membrane interactions using single-particle fluorescence microscopy.

Trace amounts of toxic heavy metal ions can contaminate water and soil and damage human health. Therefore, developing effective detection devices to monitor the content of toxic heavy metal ions in environmental contaminants is of great significance. In this study, a partially carbonized zeolitic imidazolate framework (ZIF)-decorated reduced graphene oxide (rGO) hybrid (ZIF/L-rGO) was synthesized and utilized as a bifunctional sensitive material for the electrochemical detection of trace Pb²⁺ and Cd²⁺. By rationally regulating the oxygen-containing functional groups on the rGO surface and doping ZIF nanoparticles, ZIF/L-rGO exhibited balanced hydrophilicity and good conductivity, thereby achieving superior charge transfer kinetics. For electrochemical detection of Pb²⁺ and Cd²⁺, ZIF/L-rGO-decorated electrode exhibited low limits of detection (Pb²⁺ 7.39 nM, Cd²⁺ 21.73 nM) and high sensitivity (Pb²⁺ 8.12 μA μM⁻¹ and Cd²⁺ 2.67 μA μM⁻¹), in a wide linear concentration range of 0.1–3 μM. The sensors based on ZIF/L-rGO-decorated electrodes were successfully used to detect trace levels of Pb²⁺ and Cd²⁺ in real river water with good anti-interference, reproducibility and stability. This study provides valuable insights into rational surface design strategies for graphene derivatives and their application in sensitive heavy metal ion monitoring.

Nanoplastics (NPLs) are an emerging global health concern, yet their toxicological impact remains uncertain, particularly among at-risk populations who are more susceptible to environmental stressors. While research on NPLs is expanding, most studies use commercial particles containing chemical additives, making it difficult to distinguish the effects of the polymer itself in its particulate form from those of confounding substances. In this study, we investigated the toxicity of fit-for-purpose, gold-labelled polystyrene NPLs (PS-NPLs; ∼600 nm) in mice exposed via drinking water at literature-informed doses (0.1, 1, and 10 mg kg⁻¹ per day) for 90 days, under either chow diet (CD) or Western diet (WD) conditions. Using ICP-MS, PS-NPLs were detected and quantified in intestinal contents. Moreover, low-dose exposure (0.1 or 1 mg kg⁻¹ per day, depending on diet and endpoint considered) resulted in increased body weight gain, altered mucus quality (i.e. shift in mucin O-glycan profiles), and subtle impairment of gut barrier integrity in a diet-dependent manner. Low-dose exposure also altered the gut microbiota composition in both diet groups, with diet-specific profiles, and shifted caecal metabolomic signatures only in CD-fed mice. Metabolically, low-dose PS-NPL exposure exacerbated glucose intolerance in WD-fed mice and promoted hepatic lipid accumulation and a shift in droplet size, regardless of diet. Overall, these findings demonstrate that PS-NPLs, in their particulate form and in the absence of confounding additives, can induce non-monotonic, diet-modulated effects on the gut and liver. This highlights the importance of considering particle behaviour in complex biological environments and including both healthy and at-risk populations in NPL toxicity assessments.

Environmental co-contamination with microplastics and heavy metals such as cadmium (Cd) poses emerging health risks, yet their synergistic neurotoxic effects remain poorly understood. This study investigated the synergistic neurotoxic effects of polystyrene nanoplastics (PS-NPs) and Cd co-exposure, focusing on mitochondrial dysfunction and the mitochondrial unfolded protein response (UPR^mt) in Caenorhabditis elegans (C. elegans) and PC12 cells. Results demonstrated that co-exposure to PS-NPs and Cd significantly increased Cd accumulation and oxidative stress relative to single toxicant treatments, producing greater impairment of learning-associated behavior and dopaminergic, glutamatergic and GABAergic neuronal integrity in C. elegans. In PC12 cells, co-exposure exacerbated mitochondrial membrane depolarization, ATP depletion, disrupted mitochondrial dynamics, and neuronal synaptic damage. Notably, it robustly activated the UPR^mt pathway, mediated by the transcription factor activating transcription factor 5 (ATF5) (and its homolog atfs-1 in C. elegans). In PC12 cells, the antioxidant N-acetylcysteine (NAC) pretreatment mitigated these effects, while ATF5 knockdown attenuated UPR^mt activation and synaptic damage, indicating the critical role of the ATF5-UPR^mt axis. These findings reveal that PS-NPs and Cd act synergistically to induce neurotoxicity via oxidative stress, mitochondrial dysfunction, and ATF5-mediated UPR^mt activation. This highlights the need to consider combined pollutant exposures in environmental risk assessment and to provide mechanistic insights into nanoplastic-metal co-toxicity.