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Heterogeneous catalysis holds great promise for oxidizing or reducing a range of pollutants in water. A well-recognized, but understudied, barrier to implementing catalytic treatment centers around fouling or aging over time of the catalyst surfaces. To better understand how to study catalyst fouling or aging, we selected a representative bimetallic catalyst (Pd-In supported on Al(2)O(3)), which holds promise to reduce nitrate to innocuous nitrogen gas by-products upon hydrogen addition, and six model solutions (deionized water, tap water, sodium hypochlorite, sodium borohydride, acetic acid, and sodium sulfide). Our novel aging experimental apparatus permitted single-passage of each model solution, separately, though a small packed bed reactor containing replicate bimetallic catalyst “beds” that could be sacrificed weekly for off-line characterization to quantify impacts of fouling or aging. The composition of the model solutions led to the following gradual changes in surface composition, morphology, or catalytic reactivity: (i) formation of passivating species, (ii) decreased catalytic sites due to metal leaching under acid conditions or sulfide poisoning, (iii) dissolution and/or transformation of indium, (iv) formation of new catalytic sites by the introduction of an additional metallic element, and (v) oxidative etching. The model solution water chemistry (solutes, Eh, pH) captured a wide range of conditions likely to be encountered in potable or industrial water treatment. Aging-induced changes altered catalytic activity and provided insights into potential strategies to improve long-term catalyst operations for water treatment.

Fully understanding the environmental implications of engineered nanomaterials is crucial for their safe and sustainable use. Cyanobacteria, as the pioneers of the planet earth, play important roles in global carbon and nitrogen cycling. Here, we evaluated the biological effects of molybdenum disulfide (MoS2) nanosheets on a N2-fixation cyanobacteria (Nostoc sphaeroides) by monitoring growth and metabolome changes. MoS2 nanosheets did not exert overt toxicity to Nostoc at the tested doses (0.1 and 1 mg/L). On the contrary, the intrinsic enzyme-like activities and semiconducting properties of MoS2 nanosheets promoted the metabolic processes of Nostoc, including enhancing CO2-fixation-related Calvin cycle metabolic pathway. Meanwhile, MoS2 boosted the production of a range of biochemicals, including sugars, fatty acids, amino acids, and other valuable end products. The altered carbon metabolism subsequently drove proportional changes in nitrogen metabolism in Nostoc. These intracellular metabolic changes could potentially alter global C and N cycles. The findings of this study shed light on the nature and underlying mechanisms of bio-nanoparticle interactions, and offer the prospect of utilization bio-nanomaterials for efficient CO2 sequestration and sustainable biochemical production.

Nanobiotechnology approaches to engineering crops with enhanced stress tolerance may be a safe and sustainable strategy to increase crop yield. Under stress conditions, cellular redox homeostasis is disturbed, resulting in the over-accumulation of reactive oxygen species (ROS) that damage biomolecules (lipids, proteins and DNA) and inhibit crop growth and yield. Delivering ROS-scavenging nanomaterials to plants has been shown to alleviate abiotic stress. Here we review the current state of knowledge of using ROS-scavenging nanomaterials to enhance plant stress tolerance. When present below a threshold level, ROS can mediate redox signalling and defence pathways that foster plant acclimatization against stress. We find that ROS-triggering nanomaterials, such as nanoparticulate silver and copper oxide, have the potential to be judiciously applied to crop species to stimulate the defence system, prime stress responses and subsequently increase the stress resistance of crops.

Carbon black (CB) is a nanomaterial with numerous industrial applications and high potential for integration into nano-enabled water treatment devices. However, few analytical techniques are capable of measuring CB in water at environmentally relevant concentrations. Therefore, we intended to establish a quantification method for CB with lower detection limits through utilization of trace metal impurities as analytical tracers. Various metal impurities were investigated in six commercial CB materials, and the Monarch 1000 CB was chosen as a model for further testing. The La impurity was chosen as a tracer for spICP-MS analysis based on measured concentration, low detection limits, and lack of polyatomic interferences. CB stability in water and adhesion to the spICP-MS introduction system presented a challenge that was mitigated by the addition of a nonionic surfactant to the matrix. Following optimization, the limit of detection (64 μg/L) and quantification (122 μg/L) for Monarch 1000 CB demonstrated the applicability of this approach to samples expected to contain trace amounts of CB. When compared against gravimetric analysis and UV-visible absorption spectroscopy, spICP-MS quantification exhibited similar sensitivity but with the ability to detect concentrations an order of magnitude lower. Method detection and sensitivity was unaffected when dissolved La was spiked into CB samples at environmentally relevant concentrations. Additionally, a more complex synthetic matrix representative of drinking water caused no appreciable impact to CB quantification. In comparison to existing quantification techniques, this method has achieved competitive sensitivity, a wide working range for quantification, and high selectivity for tracing possible release of CB materials with known metal contents.

In this study, soil-grown pakchoi after 2 weeks seedling cultivation were exposed to CeO

Carbohydrates and phytonutrients play important roles in tomato fruit’s nutritional quality. In the current study, Fe3O4, MnFe2O4, ZnFe2O4, Zn0.5Mn0.5Fe2O4, Mn3O4, and ZnO nanomaterials (NMs) were synthesized, characterized, and applied at 250 mg/L to tomato plants via foliar application to investigate their effects on the nutritional quality of tomato fruits. The plant growth cycle was conducted for a total of 135 days in a greenhouse and the tomato fruits were harvested as they ripened. The lycopene content was initially reduced at 0 stored days by MnFe2O4, ZnFe2O4, and Zn0.5Mn0.5Fe2O4; however, after a 15-day storage, there was no statistical difference between the treatments and the control. Moreover, the β-carotene content was also reduced by Zn0.5Mn0.5Fe2O4, Mn3O4, and ZnO. The effects of the Mn3O4 and ZnO carried over and inhibited the β-carotene after the fruit was stored. However, the total phenolic compounds were increased by ZnFe2O4, Zn0.5Mn0.5Fe2O4, and ZnO after 15 days of storage. Additionally, the sugar content in the fruit was enhanced by 118% and 111% when plants were exposed to Mn3O4 and ZnO, respectively. This study demonstrates both beneficial and detrimental effects of various NMs on tomato fruit quality and highlights the need for caution in such nanoscale applications during crop growth.

Nanoscale sulfur can be a multifunctional agricultural amendment to enhance crop nutrition and suppress disease. Pristine (nS) and stearic acid coated (cS) sulfur nanoparticles were added to soil planted with tomatoes (

The objective of the current study is to evaluate both the positive and negative effects of manganese-doped graphene quantum dots (GQD-Mn) on Capsicum annuum L. grown under salt stress. GQD-Mn was synthesized, characterized, and foliar-applied (250 mg/L, 120 mg/L, 60 mg/L) to C. annuum L. before and after the flowering stage, during which 100 mM of NaCl solution was introduced into the soil as salt stress. Controls were designed as absolute control (no nanomaterials or salt) and negative control (no nanomaterials only salt). Herein, we report that GQD-Mn offset the reduction of fruit production in salt-stressed C. annuum L. by around 40 %. However, based on a comprehensive analysis of normal alkanes (n-alkane) using gas chromatography-mass spectrometry (GC-MS), we also observed that the leaf epicuticular wax profile was disturbed by GQD-Mn, as the concentration of long-chain n-alkanes was increased. Meanwhile, the content of magnesium (Mg) and zinc (Zn) indicated a potential promoted photosynthesis activity in C. annuum L leaves. We hypothesize that the optical properties of GQD-Mn allow leaves to utilize light more efficiently, thus improving photosynthetic activities in plants to acclimate salt stress. But the increased light usage also induced heat stress on the leaf surfaces, which caused n-alkanes changes. Our results provided a unique perspective on nano-plant interaction that value both beneficial and toxic effects of nanomaterials, especially when evaluating the safety of nano-enabled agriculture in areas facing harsh environmental conditions such as salinity.

Verticillium wilt, caused by Verticillium dahliae, is one of the major diseases of eggplants. Nanoparticles (NPs) of CuO, Mn2O3, and ZnO were sprayed alone onto leaves of young eggplants and in different combinations and rates, and then seedlings were transplanted into soil infested with V. dahliae in the greenhouse and field between 2015 and 2018. All combinations of NPs were consistently less effective than CuO NPs applied alone at 500 µg/ml at increasing disease suppression, biomass, and fruit yield. CuO NPs were associated with an increase in fruit yield (17 and 33% increase) and disease suppression (28 and 22% reduction) in 2016 and 2017, respectively, when compared with untreated controls. However, this effect was negated in the greenhouse and field experiments when CuO NPs were combined with Mn2O3. Combining NPs of CuO with ZnO resulted in variable effects; amendments increased growth and suppressed disease in greenhouse experiments, but results were mixed in the field. Leaf tissue analyses from the greenhouse experiments showed that Cu concentration in leaves was reduced when CuO NPs were combined with other NPs, even when application rates were the same amount. A simple competition for entry sites may explain why combinations of CuO NPs and Mn2O3 NPs reduced efficacy but does not explain the lack of inhibition between Cu and Zn. NPs of CuO performed better than their larger bulk equivalent, and studies on application rate found 500 µg/ml was optimal. No phytotoxicity, as determined, by leaf burning, necrotic spots, or dead apical buds was noted even at the highest combined rates of 1,500 µg/ml.

The application of nanotechnology in the field of agriculture as nanofertilizers or nanopesticides is receiving increased attention from regulatory agencies and research institutions worldwide. Soi...

In this study, spinach plants exposed to fresh/unweathered (UW) or weathered (W) copper compounds in soil were analyzed for growth and nutritional composition. Plants were exposed for 45 days to fr...

Heavy metal contamination in raw materials has spread widely in the United States. The high increased number of recalls in consumer products and the lack of stricter regulations in the raw materials to be used in the jewelry industry have raised concerns among consumers. Studies in low-cost jewelry have shown the presence and high content of heavy metals; this environmental problem led to a child's death after swallowing a charm containing elevated levels of lead (Pb). Exposure to heavy metals, through inhalation, mouth, and skin contact, causes adverse health effects in children and adults. Exposure to lead affects mainly the nervous system and brain development; exposure to cadmium (Cd) causes damage to liver, kidneys, and lungs, and potentially leads to cancer; exposure to nickel (Ni) causes severe dermatitis. Thus, the importance and impact of studies of this nature cannot be overstated. As heavy metal contamination has increased in the United States, this research fills an important knowledge gap between previous studies conducted on low-cost jewelry and fine jewelry. In this study, conducted in the Paso del Norte region, one hundred and forty-three pieces of fine jewelry were evaluated for the presence of heavy metals using X-ray fluorescence (XRF) spectroscopy. Our study showed that 61 samples (42.7 %) exhibited the presence of Ni in the metal alloy, prevailing in jewelry pieces with lower percentage of gold. Eighteen samples showed the presence of Pb in gemstones, 11 pieces of these samples (7.7 % total) had33.3 % gold (≤10 K); however, none of the samples showed the presence of Pb in the metal alloy. Further research is needed to evaluate the bioaccessibility of Pb in these gemstones, which may pose a potential health hazard to children and adults in the US Paso del Norte region and throughout the world.

In this study, we investigated the effects of citric acid (CA) coated copper oxide nanoparticles (CuO NPs) and their application method (foliar or soil exposure) on the growth and physiology of soybean (Glycine max). After nanomaterials exposure via foliar or soil application, Cu concentration was elevated in the roots, leaves, stem, pod, and seeds; distribution varied by plant organ and surface coating. Foliar application of CuO NPs at 300 mg/L and CuO-CA NPs at 75 mg/L increased soybean yield by 169.5% and 170.1%, respectively. In contrast, foliar and soil exposure to ionic Cu with all treatments (75 and 300 mg/L) had no impact on yield. Additionally, CuO-CA NPs at 300 mg/L significantly decreased Cu concentration in seeds by 46.7%, compared to control, and by 44.7%, compared to equivalent concentration of CuO NPs. Based on the total Cu concentration, CuO NPs appeared to be more accessible for plant uptake, compared to CuO-CA NPs, inducing a decrease in protein content by 56.3% and inhibiting plant height by 27.9% at 300 mg/kg under soil exposure. The translocation of Cu from leaf to root and from the root to leaf through the xylem was imaged by two-photon microscopy. The findings indicate that citric acid coating reduced CuO NPs toxicity in soybean, demonstrating that surface modification may change the toxic properties of NPs. This research provides direct evidence for the positive effects of CuO-CA NPs on soybean, including accumulation and in planta transfer of the particles, and provides important information when assessing the risk and the benefits of NP use in food safety and security.

Micronutrient deficiencies in global food chains are a significant cause of ill health around the world, particularly in developing countries. Agriculture is the primary source of nutrients required for sound health, and as the population has continued to grow, the agricultural sector has come under pressure to improve crop production, in terms of both quantity and quality, to meet the global demands for food security. The use of engineered nanomaterial (ENM) has emerged as a promising technology to sustainably improve the efficiency of current agricultural practices as well as overall crop productivity. One promising approach that has begun to receive attention is to use ENM as seed treatments to biofortify agricultural crop production and quality. This review highlights the current state of the science for this approach as well as critical knowledge gaps and research needs that must be overcome to optimize the sustainable application of nano-enabled seed fortification approaches.

The application of nanomaterials as a method to overcome plant stress and increase crop yield is relatively new as compared to the use of fertilizers and pesticides in agricultural production. In t...

Nanoparticles (NPs) are increasingly used as agrochemical components through foliar spraying such as foliage fertilizers or pesticides. However, the understanding of the mechanisms of nanoparticle absorption and translocation from the leaf surface is limited. In this study, ZnO NPs (30 nm) labeled with fluorescein isothiocyanate (FITC) were foliar applied to wheat leaf tissues to investigate the process of attachment and absorption. Using laser confocal microscopy, we observed that FITC–ZnO NPs cross the leaf epidermis through the stomata and accumulate first in the apoplast, followed by subsequent transport to mesophyll cells. The Zn concentrations in wheat leaf apoplast and cytoplasm decreased by 33.2% and 8.3% with stomatal aperture diameter reduction, respectively; the apoplastic Zn concentration is influenced more by stomatal aperture than the cytoplasmic Zn level. Scanning electron microscopy with energy-dispersive X-ray analysis was used to map Zn in the wheat leaves and data suggest a different Zn distribution for ZnO NPs and ZnSO4. Zn ions in ZnO NP-treated samples are heterogeneously distributed in comparison with those in ZnSO4-treated samples. The results indicate that the main route to cross the wheat leaf epidermis for ZnO NPs is via the stomata; then these nanoparticles accumulate and release Zn ions in the apoplast, and the released Zn ions and ZnO NPs are absorbed by mesophyll cells. Our findings demonstrate how ZnO NPs cross the wheat leaf epidermis, distribute within mesophyll tissues, and enter into plant cells, and this information is useful for the development of sustainable nano-enabled platforms for nanoscale micronutrient delivery.

Currently, over a billion people around the world lack access to clean drinking water, industrial wastewater treatment and reuse is limited, and conventional water treatment systems cannot adequately treat all contaminants of concern. Nanotechnology-enabled water treatment (NWT) has begun to emerge as a viable option to address many of the problems facing the water treatment status quo, either through cost reducing performance enhancements or filling unmet niches. Advancements in fundamental nanoscience allow unprecedented use of catalysis and energy from across the broad electromagnetic spectrum, as well as unique physicochemical properties, to purify drinking water, treat industrial wastewater, and access unconventional water supplies. However, before fully adopting NWT, it is imperative that the devices are both safe and sustainable, enhancing acceptance from consumers, government, non-government organizations, and industry. We suggest that we are in a unique window of time to “do nano right” by making key sustainability considerations very early in nano-water technology development. To this end, we have developed a framework based on three guiding research questions aimed at understanding the breadth of sustainability considerations for NWT at each of the four major life cycle stages – extraction, production, use, and end-of-life. In following this framework, researchers and product developers can design nano-enabled water treatment devices that perform well and are both safe and sustainable. By presenting the current state of sustainable NWT and specifying gaps in the literature, the present review aims to further develop NWT to be the best alternative to conventional water treatment across a variety of sectors.

The accumulation of engineered nanomaterials (ENMs) will increase as more applications are discovered for their unique properties and characteristics. Additionally, the presence of nanomaterials in...

Fully understanding the environmental implications of engineered nanomaterials is crucial for their safe and sustainable use. Cyanobacteria, as the pioneers of the planet earth, play important roles in global carbon and nitrogen cycling. Here, we evaluated the biological effects of molybdenum disulfide (MoS

Polycyclic aromatic hydrocarbons (PAHs) have the potential to cause cancer, teratogenicity, and mutagenesis in humans. Long-term plant safe production relies on how PAHs are transported and coordinated across organs. However, the acropetal transfer mechanism of PAHs in staple crop stems, particularly in xylem, a critical path, is unknown. Herein, we first confirmed the presence of specific interaction between the proteins and phenanthrene by employing the magnetic phenanthrene-bound bead immunoassay and label free liquid chromatograph mass spectrometer (LC-MS/MS), suggesting that peroxidase (uniprot accession: A0A3B5XXD0) and unidentified proteins (uniprot accession: A0A3B6LUC6) may function as the carriers to load and acropetally translocate phenanthrene (a model PAH) in wheat xylem. This specified binding of protein-phenanthrene may form through hydrophobic interactions in the conservative binding region, as revealed by protein structural investigations and molecular docking. To further investigate the role of these proteins in phenanthrene solubilization, phenanthrene exposure was conducted: a substantial quantity of peroxidase was produced; an unusually high expression of uncharacterized proteins was observed, indicating their positive effects in the acropetal transfer of phenanthrene in wheat xylem. These data confirmed that the two proteins are crucial in the solubilization of phenanthrene in wheat xylem sap. Our findings provide fresh light on the molecular mechanism of PAH loading in plant xylem and techniques for ensuring the security of staple crops and improving the efficacy of phytoremediation in a PAH-contaminated environment.

Misunderstanding on the claims and statements in Hong et al. (2021) were clarified.

A series of novel absorbents based on Cu-BDC MOFs decorated over graphene oxide (GrO) and carbon nanotubes (CNTs) hybrid nanocomposites, namely Cu-BDC@GrO and Cu-BDC@CNT, are synthesized via a facile and one-pot green solvothermal method for water remediation. The nanocomposites were characterized by XRD, TEM, SEM, EDS, Raman, FTIR, TGA, XPS, Zetasizer and ICP-OES instruments. XRD results confirmed the high crystalline structure of the synthesized hybrid nanocomposites. Morphological analysis by SEM and TEM verified the successful decoration of nano-sized Cu-BDC MOFs over GrO and CNT platforms; whereas, EDS and XPS analysis confirmed the presence of all components in the hybrid nanocomposites. Bisphenol A was used in this study as a model organic pollutant that is sometimes present in the industrial wastewater to test the adsorption capacity of the prepared hybrid nanomaterials toward their removal from water. The hybrid nanomaterials showed remarkable adsorption capacity of 182.2 and 164.1 mg/g toward the removal of BPA, which was several times higher than that of 60.2 mg/g for Cu-BDC MOF itself. The Langmuir, Freundlich, Temkin and D-R isotherm models were applied to analyze the experimental data and the results revealed that the Freundlich model describes the experimental data best. A kinetic study was carried out and it showed that the prepared nanomaterials could remove maximum amount of BPA from water in 30 min. The pseudo-first order, pseudo-second order and intra-particle diffusion models were applied to evaluate the kinetic data and the results suggested that the kinetics data could be well fitted to the pseudo-second order kinetic model. Additionally, the BAP adsorption process onto the hybrid nanocomposites was spontaneous and exothermic. The π-π interactions between the BPA and hybrid nanomaterials played a vital role during the BPA adsorption process. The higher adsorption capacity and water stability makes them a good candidate for water remediation applications.

Plant response to microelements exposure can be modulated based on particle size. However, studies are lacking on the roles of particle size and specific microelements in mixed exposure systems designed for plant nutrition, rather than toxicology. Here, an addition-omission strategy was used to address particle-size and element-specific effects in soybean exposed to a mixture of nano and bulk scale oxide particles of Zn (2 mg Zn/kg), Cu (1 mg Cu/kg) and B (1 mg B/kg) in soil. Compared to the control, mixtures of oxide particles of both sizes significantly (p

More and more engineered nanoparticles (NPs) are being released into the environment with the accelerated manufacture and use of nanomaterials. The discharged NPs have the possibility of interacting with co-existing contaminants, resulting in joint toxicities that are poorly understood. Here, we investigated the individual and joint toxicities of carbon nanotubes (CNTs), a commonly utilized NP, and pentachlorophenol (PCP), a toxicant, to a model bacterium, Escherichia coli. Bacterial growth inhibition, cell morphology and structure changes, surface properties of CNTs and bacteria, interactions among CNTs, PCP, and bacteria, oxidative stress, and the bioaccumulation of CNTs and PCP were assayed. Transcriptome sequencing (RNA-seq) technology was used to analyze bacterial responses to CNTs and/or PCP in the co-exposure system. As determined by the toxic unit index, co-exposure of CNTs and PCP led to antagonistic toxicity to bacterial growth. The presence of PCP decreased CNT bioaccumulation (9.2 mg/L PCP decreased the accumulated concentration of CNTs by 31.8% compared with 0 mg/L PCP). At the transcriptional level, CNTs attenuated the PCP-induced disturbances of gene expression in biosynthetic, protein metabolic, and small molecule metabolic processes, as well as for organelles. This work is of significance to understanding potential ecological risk of discharged CNTs.

The use of nanomaterials in agriculture as nanofertilizers, nanopesticides, or nano-enabled sensors to increase crop yield is gaining increasing interest. Engineered nanomaterials (ENMs) can improve crop productivity by influencing fertilizer nutrient availability in soil and uptake by plants. These materials can suppress crop diseases by directly acting on pathogens through a variety of mechanisms, including the generation of reactive oxygen species (ROS). ENMs may also suppress disease indirectly by improving crop nutrition and enhancing plant defense pathways. Efficient use of ENMs may complement or replace conventional fertilizers and pesticides, subsequently reducing the environmental impact of agricultural practices. This review evaluates the current literature on ENMs used as pesticides and fertilizers, and highlights critical knowledge gaps that must be addressed to ensure sustainable application of nanotechnology in agriculture so as to achieve global food security.

Engineered Nanomaterials (ENMs) are revolutionizing our daily lives, industry, and agriculture. Along with their novel applications, major concerns have emerged due to the potential toxicity to biological systems. Since soils are considered the main destination for ENMs, research focused on their interaction with plants is gaining more attention, especially at the physiological and biochemical levels. This review addresses the capacity of some plants to accumulate ENMs or released ions, highlighting the beneficial and detrimental effects and the potential use of some plants to remediate ENM-contaminated environments. Although the uptake process depends on multiple factors, the literature suggests that concentrations

The unique physico-chemical, electronic, redox, and UV-absorption properties of the engineered nano-particles (ENPs) make them suitable for many industrial applications including consumer goods. Agriculture is a major area where nanotechnologies are applied. Therefore, soil/sediment becomes an important environmental sink for ENP waste disposal. Hence, the fate and transport of ENPs in soil is of particular interest to the scientific community. This short review summarizes the recent findings of studies dealing with the related fundamental concepts. It touches upon the physico-chemical properties of soil and those of ENPs, the soil and solution chemistries, the environmental factors, and the influence of other chemical moieties as possible factors affecting the fate of ENPs in soil.

Bulk Cu compounds such as Cu(OH)2 are extensively used as pesticides in agriculture. Recent investigations suggest that Cu-based nanomaterials can replace bulk materials reducing the environmental impacts of Cu. In this study, stress responses of alfalfa (Medicago sativa L.) seedlings to Cu(OH)2 nanoparticle or compounds were evaluated. Seeds were immersed in suspension/solutions of a Cu(OH)2 nanoform, bulk Cu(OH)2, CuSO4, and Cu(NO3)2 at 25 and 75 mg/L. Six days later, the germination, seedling growth, and the physiological and biochemical responses of sprouts were evaluated. All Cu treatments significantly reduced root elongation (average = 63%). The ionic compounds at 25 and 75 mg/L caused a reduction in all elements analyzed (Ca, K, Mg, P, Zn, and Mn), excepting for S, Fe and Mo. The bulk-Cu(OH)2 treatment reduced K (48%) and P (52%) at 75 mg/L, but increased Zn at 25 (18%) and 75 (21%) mg/L. The nano-Cu(OH)2 reduced K (46%) and P (48%) at 75 mg/L, and also P (37%) at 25 mg/L, compared with control. Confocal microscopy images showed that all Cu compounds, at 75 mg/L, significantly reduced nitric oxide, concurring with the reduction in root growth. Nano Cu(OH)2 at 25 mg/L upregulated the expression of the Cu/Zn superoxide dismutase gene (1.92-fold), while ionic treatments at 75 mg/L upregulated (∼10-fold) metallothionein (MT) transcripts. Results demonstrated that nano and bulk Cu(OH)2 compounds caused less physiological impairments in comparison to the ionic ones in alfalfa seedlings.

Given the known presence of SARS-Cov-2 in wastewater, stemming disease spread in global regions where untreated effluent in the environment is common will experience additional pressure. Though development and preliminary trials of a vaccine against SARS-CoV-2 have been launched in several countries, rapid and effective alternative tools for the timely detection and remediation of SARS-CoV-2 in wastewater, especially in the developing countries, is of paramount importance. Here, we propose a promising, non-invasive technique for early prediction and targeted detection of SARS-CoV-2 to prevent current and future outbreaks. Thus, a combination of nanotechnology with wastewater-based epidemiology and artificial intelligence could be deployed for community-level wastewater virus detection and remediation.

Nanoscale zero-valent iron (nZVI) has been widely applied in the environmental field to degrade organic pollutants. The potential risk posed from nZVI on crop species is not well understood and is critical for sustainable application in the future. In this study, maize (Zea mays L.) plants were cultivated in field soils mixed with nZVI at 0, 50, and 500 mg/kg soil for four weeks. Upon exposure to 500 mg/kg nZVI, ICP-MS results showed that Fe accumulated by roots and translocated to leaves was increased by 36% relative to untreated controls. At 50 mg/kg, root elongation was enhanced by 150–200%; at 500 mg/kg, pigments, lipid peroxidation, and polyphenolic levels in leaves were increased by 12, 87 and 23%, respectively, whereas the accumulation of Al, Ca, and P were decreased by 62.2%, 19.7%, and 13.3%, respectively. A gas chromatography–mass spectrometry (GC–MS) based metabolomics analysis of maize roots revealed that antioxidants and stress signaling-associated metabolites were downregulated at 50 mg/kg, but were upregulated at 500 mg/kg. At 50 mg/kg, the content of glutamate was increased by 11-fold, whereas glutamine was decreased by 99% with respect to controls. Interestingly, eight metabolic pathways were disturbed at 50 mg/kg, but none at 500 mg/kg. This metabolic reprogramming at the lower dose represented potential risks to the health of exposed plants, which could be particularly important although no phenotypic impacts were noted. Overall, metabolites analysis provides a deeper understanding at the molecular level of plant response to nZVI and is a powerful tool for full characterization of risk posed to crop species as part of food safety assessment.

This work presents the most extensive proteomic description of Arabidopsis thaliana in the knowledge of its responses to BPA and TiO2-NPs. Previous studies have reported that nanoparticles (NPs) and Bisphenol A (BPA) are toxic to the environment. However, the jointed toxicity is not yet well understood. This study was aimed to investigate the combined toxicity of BPA and TiO2-NPs to plants. Model plant Arabidopsis thaliana was selected as the target plant. The seedlings were randomly separated into 5 groups and treated with BPA (1000, 100, 10 and 0 µg/kg) and TiO2-NPs (100, 10, 1 and 0 mg/kg). The plant height, biomass and root length indicated no significant toxicity of low concentration of BPA and TiO2-NPs to the growth. In the results of comparative proteomics, both positive and negative effects were observed in root growth, plant development and energy metabolism, et.al, according to GO and KEGG analysis.

In this study, spinach plants exposed to fresh/unweathered (UW) or weathered (W) copper compounds in soil were analyzed for growth and nutritional composition. Plants were exposed for 45 days to freshly prepared or soil-aged (35 days) nanoparticulate CuO (nCuO), bulk-scale CuO (bCuO), or CuSO

Metallic nanoparticles (NPs) are being extensively used in electronics, cosmetics, sporting goods, and medicine. Only recently, use of metallic nanomaterials extended to agricultural production, which could lead to their buildup in arable lands and affect soil productivity. Several investigations, with different NPs and under different exposure conditions, have been conducted to understand the effects of metallic NPs on terrestrial plants. These studies have propelled the application of NPs as agrochemicals that are able to supply nutrients, combat pests and weeds, and alleviate abiotic stress. The applications of novel, high-throughput technologies and advanced spectroscopic techniques have been of great help to understand the complex metabolic responses of plants to NP exposure. However, there is still limited information about the interactions of metallic NPs with plant molecules and soil components and their repercussions on agricultural productivity. This work discusses the benefits and disadvantages that metallic NPs might represent for crops. Additionally, the effects of the metallic NPs on plant physiology are analyzed by scrutinizing recent spectroscopic and gene expression/transcriptomic studies.

Foliar spray of engineered nanoparticles (NPs) as nanofertilizers, nanopesticides, nanosensors, and nanocarriers is increasingly being employed in the agricultural industry. Foliar spraying of NPs improves the effectiveness of plant protection technologies compared to traditional soil–root application. Foliar-sprayed NPs mainly enter the leaves through stomata and are transported to different plant parts via apoplastic and symplastic pathways. Foliar NPs enhance defenses and resistance against pests and diseases and improve the yield and quality of crops. However, the mechanisms of damage caused by foliar NPs need further elucidation. Moreover, important factors limiting foliage uptake of NPs such as wax deposits on leaf surfaces, environmental factors (e.g., light, temperature, and humidity), and physical and chemical properties of NPs should be investigated to further improve this technology.

This chapter highlights interactions of nanomaterials with plants at the level of plant life cycle stages: germination, seedling development, growth, and includes transgenerational influence of nanomaterial exposures. About a decade ago, scientists moved from the traditional method of petri-dish-based germination study to more expansive long-term exposure studies up to half maturity or full maturity of the plant. Such studies have shown that responses depend on the physiochemical properties of the nanomaterial and its interaction with plant material-environmental conditions including the type of plant (mono or dicotyledonous), growing medium (soil matrix or hydroponics), contact type (foliar or root exposure), edible portion (root, stem, leaf or flower/fruit), constitution of the nanomaterial (powder or suspension), and the exposure concentration and duration. The exposure concentration determines beneficial (nutrient stimulatory) or detrimental (nutrient inhibitive) effects on the plant. This chapter includes both metal-based and carbon-based engineered nanoparticles (ENPs). The models of plant study range from rice, corn, cereal grains, and other food crops (monocot) to tomato, peas and beans, and cucumber (dicot) among others. Another important concern addressed is harmful elemental bioaccumulation in the plant and its biomagnification in the food chain.

Rutile titanium dioxide nanoparticles (nTiO2) were weathered in field soil at 0, 100, 200, and 400 mg Ti/kg soil for four months. Two types of nTiO2 with different surface coatings (hydrophilic and hydrophobic), uncoated nTiO2 (pristine), and the untreated control were included. Thereafter, carrot seeds (Daucus carota L.) were sown in those soils and grown in a growth chamber for 115 days until full maturity. A comparison was made between this and our previous unaged study, where carrots were treated in the same way in soil with freshly amended nTiO2. The responses of plants depended on the nTiO2 surface coating and concentration. The aged hydrophobic and hydrophilic-coated nTiO2 induced more positive effects on plant development at 400 and 100 mg Ti/kg soil, respectively, compared with control and pristine treatments. Taproot and leaf fresh biomass and plant height were improved by up to 64%, 40%, and 40% compared with control, respectively. Meanwhile, nutrient elements such as Fe in leaves, Mg in taproots, and Ca, Zn, and K in roots were enhanced by up to 66%, 64%, 41, 143% and 46%, respectively. However, the contents of sugar, starch, and some other metal elements in taproots were negatively affected, which may compromise their nutritional quality. Taken together, the overall growth of carrots was benefited by the aged nTiO2 depending on coating and concentration. The aging process served as a potential sustainable strategy to alleviate the phytotoxicity of unweathered nanoparticles.