Environmental Science: Nano最新文献

The risk of long-term global food insecurity is being exacerbated by climate change, as well as by a range of other socio-economic and political factors. Conventional agriculture has been heavily dependent on agrochemical use for decades, and although this has increased food production in a way that has benefited billions of citizens, the subsequent damage to terrestrial and aquatic ecosystems has been significant. This is in part due to agrochemical delivery and use efficiency levels that are often 30% or less, leading to over-application to achieve acceptable yield but that results in a significant negative environmental footprint of agriculture. Recent advances in agrochemical delivery have sought to mimic nanodrug delivery systems in health, where materials design and delivery is engineered to be efficient, precise and safe. Consequently, a number of agrochemical delivery strategies have been described in the literature, offering equivalent or enhanced efficacy with reduced environmental impact. Several recent studies have extended this work to targeting specific biotic and abiotic plant stresses, with the goal of developing more sophisticated nanostimulants and nanofertilizers that promote overall climate resilience in agriculture. This paper will review and analyze the vast potential of these agrochemical delivery systems, including an assessment of future directions that could validate the widespread application of nano-enabled agriculture as a critical tool in combatting global food insecurity in a changing climate.

This study introduces M_CNF/biochar, a novel plant growth stimulant comprising bamboo-derived biochar, boron (B), molybdenum (Mo), and copper (Cu)-carbon nanofibers (CNF). The prepared micro-nano formulation is successfully used to deliver the B–Mo–Cu multi micronutrients to Cicer arietinum (chickpea) plant, with the CNFs acting as a translocator for the micronutrients. The synthesized material is thoroughly characterized for its physicochemical properties using various analytical techniques. The results show that a M_CNF/biochar-dose of 1 g kg⁻¹ soil significantly enhances plant growth, as indicated by an increase in the fresh biomass, root and shoot lengths, and protein and chlorophyll contents. Furthermore, the soil's water-holding capacity increases by more than 90% with the mixing of M_CNF/biochar. The results also reveal that the total nitrogen content of the soil amended with M_CNF/biochar increases more than 4 times, post-30 days of plant growth, indicating an improvement in the nitrogen fixation capacity of the rhizosphere. This study has successfully presented the bamboo-derived biochar modified with micronutrients for sustainable agriculture.

In order to reduce phosphorus (P) losses due to P leaching, enhance the adsorption capacity of soil for P, and ensure environmental safety and optimal crop growth, a multitude of calcium-containing natural minerals and industrial-synthesized materials have been employed in a vast array of applications. However, the potential of nano calcium carbonate (NCC) with high surface electronic activity and a large specific surface area to serve as ideal slow-release P fertilizers has rarely been explored in academic research. In this study, the optimum application rate of NCC and its effect on soil P processes were determined by setting up five different treatments, namely, 0 NCC, 0.15% NCC, 0.30% NCC, 0.45% NCC, and 0.60% NCC, through a soil column leaching experiment as well as a two-year field experiment (2020–2022). The results showed that all treatments of NCC reduced leaching losses of soluble P. Compared with 0 NCC, 0.30% NCC and 0.45% NCC increased soil available P (AP) content and alkaline phosphatase (ALP) activity. In comparison to the 0 NCC, the 0.30% NCC treatment resulted in a notable increase in the relative abundance of several bacterial groups, including Actinobacteria, Acidobacteria, Haliangium, Solirubrobacter, Actinoplane, Nocardioides, Dongia, and Gemmatimonas. Additionally, the relative abundance of ppx, ppa, and phoD was elevated, while the relative abundance of Firmicutes, Bacillus, phnE, and phnC was reduced. The 15% NCC treatment resulted in a notable increase in the abundance of gcd. NCC treatments increased P concentrations in wheat stems, leaves, and spikes. NCC promoted wheat P uptake by regulating the rate of P release, and by activating ALP activity and increasing soil AP content by promoting soil bacterial-mediated mineralization of organic P and solubilization of inorganic P.

Proteins like albumin are found in various environmental and living systems, and they have wide applications in various fields. It is known that the functional, conformational and sorption properties of proteins are significantly affected by various surrounding conditions and chemicals. Micro-/nano-plastics are an emerging issue for the environment, living systems and industrial applications, and they can easily leach, sorb and/or desorb chemicals. These processes can change medium characteristics. However, studies on the impact of micro-/nano-plastics on the chemical and biological behaviors of proteins are lacking. Herein, we investigated the interactions between bovine serum albumin and polyethylene terephthalate micro-/nano-plastics by assessing the binding, structural and oxidative characteristics of proteins using UV-VIS, fluorescence and Raman spectroscopies and molecular docking studies. Additionally, the biological impact of non-treated and micro-/nano-plastic-treated proteins was examined by assessing cytotoxicity (mitochondrial activities and membrane integrity) and oxidative stress (antioxidants, reactive oxygen species, catalase, glutathione reductase, and superoxide dismutase) of a human lung epithelial cell (A549) in vitro model. Binding results showed that micro-/nano-plastics had an affinity for proteins and varied according to the exposure concentration and duration. Molecular simulations revealed that micro-/nano-plastics were bound to the active sites of proteins, which caused structural and functional changes. Raman spectral results further confirmed the structural changes in the proteins after the treatments. Moreover, it was observed that the chemical (e.g., zeta potentials, aromatic side chains and folding) and oxidative indicators of proteins were significantly affected. The exposure of lung cells to non-treated and micro-/nano-plastic-treated proteins resulted in different mitochondrial and membrane activities. The oxidative stress indicators revealed that antioxidants, reactive oxygen species and their balance were significantly affected, and the cell viabilities of superoxide dismutase and glutathione reductase were more influenced than those of catalase. The correlation results also indicated that folding, aromatic chain, quenching constant and oxidative potentials of proteins were more effective indicators of the cellular responses of micro-/nano-plastics-treated proteins than zeta potentials. Thus, all the results indicated the side effects of micro-/nano-plastics on proteins owing to their leaching and sorption.

Muskmelon Fusarium wilt (MFW) disease caused by Fusarium oxysporum f. sp. melonis (FOM) is one of the major challenges faced in muskmelon production worldwide. Trichoderma sp., as a well-known biocontrol fungus, and AgNPs have been widely used to control plant diseases. However, few literature studies have been reported on the combined application of AgNPs and Trichoderma sp. against soil-borne diseases. This study was aimed at investigating the inhibitory effect of AgNPs and Trichoderma sp. to FOM and the control effect of the combined application of AgNPs and Trichoderma koningiopsis (TK) against MFW. The characteristics of different AgNPs were also analyzed using various techniques, such as XRD, TEM-EDS, FTIR and TEM. Results showed that TK had the highest inhibition rate (63.77%) against FOM among the four Trichoderma strains and had the best resistance to AgNPs, with an average inhibition rate of 5.76% on mycelium growth. Different AgNPs and their combinations had different inhibitory effects on the growth and sporulation of FOM. The inhibition rate of the AgNPs-TH (T. hamatum) and AgNPs-TK (T. koningiopsis) combination (AgNPs-C) was the highest, reaching up to 50.83%. The specific absorption peaks of AgNPs-TH, AgNPs-TK and AgNPs-C occurred at 420 nm, 323 nm and 320 nm, respectively. XRD and TEM-EDS showed that the crystalline structured nanoparticles were spherical with a diameter ranging from 16.5 nm to 23.4 nm. FTIR results showed that there were more functional group moieties (–OH, –CH₃, –C–O, etc.) on AgNPs-C, which were involved as a capping and reducing agent in the biosynthesis of AgNPs. The combined application of AgNPs-C and TK decreased the incidence (11.11%) and disease index (2.78) compared with CK-F (77.78% and 48.61, respectively) and improved the growth and plant fresh weight. Thus, the combined application of AgNPs and biocontrol agent (TK) could be used to improve the growth and development of muskmelon and suppress the MFW disease, providing an alternative approach to realize an eco-friendly control of the soil-borne disease.

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants that pose significant risks to the environment and human health. Phenanthrene (PHE), a model PAH, has been shown to cause toxic effects on plants, particularly on their photosynthetic performance. This study investigated the potential of nano-biochar (nBC) derived from rice straw to alleviate the phytotoxicity of PHE in wheat seedlings. We hypothesized that the high adsorption capacity and unique properties of nBC, such as its high surface area, porous structure, and abundant functional groups, could reduce the bioavailability and toxicity of PHE, thereby mitigating its adverse effects on wheat growth and photosynthesis. Wheat seedlings were exposed to different treatments, control, 1.0 mg L⁻¹ nBC, 1.0 mg L⁻¹ PHE, 1.0 mg L⁻¹ PHE + 0.5 mg L⁻¹ nBC, and 1.0 mg L⁻¹ PHE + 1.0 mg L⁻¹ nBC. The results showed that nBC alleviated PHE-induced chlorosis and improved plant growth. Compared to the PHE-single treatment, the application of 1.0 mg L⁻¹ nBC increased chlorophyll content by 14.54% and enhanced photosynthetic efficiency, as evidenced by increases in Fv/Fm (2.48%), q_P (9.06%), and Φ_PSII (3.81%). Furthermore, nBC reduced the accumulation of PHE in wheat tissues, with the PHE concentration in the PHE-single treatment being 1.77 and 1.61 times higher than that in the 1.0 mg L⁻¹ nBC treatment for shoots and roots, respectively. The non-photochemical quenching (NPQ) values decreased by 13.64% in the presence of 1.0 mg L⁻¹ nBC, indicating reduced heat dissipation and improved photosynthetic performance. The alleviation of PHE toxicity by nBC can be attributed to its high adsorption capacity, which limits the uptake of PHE by plants. Additionally, the photoelectric effect of nBC may directly promote photosynthesis by enhancing electron transport and providing reducing power for ATP and NADPH synthesis. The use of nBC for the remediation of PAH-contaminated soils offers several advantages, including sustainability, eco-friendliness, and additional benefits such as carbon sequestration and soil quality improvement. These findings highlight the potential of nBC as an effective amendment for the remediation of PAH-contaminated soils and the protection of crops under PAH stress.