La2O3 Nanoparticles: Study of Uptake and Distribution in Pfaffia glomerata (Spreng.) Pedersen by LA-ICP-MS and μ-XRF

Dose-Dependent Effect on Plant Growth of Exposure to Metal-Organic Framework MIL-101(Cr)

With the increasing use of metal-organic frameworks (MOFs), they will inevitably enter the environment intentionally or unintentionally. However, the effects of MOFs on plant growth are poorly understood. Here, we investigated the effects of exposure of the rhizosphere to MOFs on plant growth. MIL-101(Cr) was selected as a research model due to its commercial availability and wide use. Soybean plants at the two-leaf stage were subjected to various durations (1-7 days) and concentrations (0-1000 mg/L) of exposure in hydroculture with a control group treated with ultrapure water. We found that MIL-101(Cr) had a positive effect on soybean growth at a lower dose (i.e., 200 mg/L); however, at higher doses (i.e., 500 and 1000 mg/L), it exhibited significant toxicity to plant growth, which is evidenced by leaf damage. To investigate the mechanism of this effect, we used Cr as an indicator to quantify, track, and image MIL-101(Cr) in the plant with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Results indicated that MIL-101(Cr) primarily accumulated in the cortex of roots (up to 40 times higher than that in stems), with limited translocation to stems and negligible presence in leaves and cotyledons. In addition, metabolomic analysis of soybeans indicated that low-dose MIL-101(Cr) could increase the sucrose content of soybean roots to promote plant growth, while a high dose could induce lipid oxidation in roots. This study provides valuable insights into the ecological toxicology of MOFs and underscores the importance of assessing their environmental impact for sustainable agricultural practices.

Tracking and imaging nano-plastics in fresh plant using cryogenic laser ablation inductively coupled plasma mass spectrometry

Tracking and imaging of nano-plastics are extremely challenging, especially in fresh biological samples. Here, we propose a new strategy in which polystyrene (PS) was doped with the europium chelate Eu (DBM)3bpy to quantify, track, and in situ image nano-plastics in fresh cucumber based on inherent metals using cryogenic laser ablation inductively coupled plasma mass spectrometry (cryo-LA-ICP-MS). The cryogenic conditions provide a stable condition for imaging fresh cucumber, suppressing the evaporation of water in fresh plants, and maintaining the original structure of plants with respect to room temperature imaging in LA-ICP-MS. The plants were cultivated in two types of nano-plastics solutions with low (50 mg/L) and high (200 mg/L) concentrations for 9 days. The results showed that nano-plastics mainly enrich the roots and have negative effects, which decrease the trace elements of Zn, Mn, and Cu in cucumber. Smaller PS particles are able to penetrate the plant more easily and inflict serious damage. Novel imaging method provides a novel insight into the tracking and imaging of nano-plastics in fresh plant samples. The results illustrated that nano-plastics deposition on plants has the potential to have direct ecological effects as well as consequences for potential health.

Transport of Nanoparticles into Plants and Their Detection Methods

Nanoparticle transport into plants is an evolving field of research with diverse applications in agriculture and biotechnology. This article provides an overview of the challenges and prospects associated with the transport of nanoparticles in plants, focusing on delivery methods and the detection of nanoparticles within plant tissues. Passive and assisted delivery methods, including the use of roots and leaves as introduction sites, are discussed, along with their respective advantages and limitations. The barriers encountered in nanoparticle delivery to plants are highlighted, emphasizing the need for innovative approaches (e.g., the stem as a new recognition site) to optimize transport efficiency. In recent years, research efforts have intensified, leading to an evendeeper understanding of the intricate mechanisms governing the interaction of nanomaterials with plant tissues and cells. Investigations into the uptake pathways and translocation mechanisms within plants have revealed nuanced responses to different types of nanoparticles. Additionally, this article delves into the importance of detection methods for studying nanoparticle localization and quantification within plant tissues. Various techniques are presented as valuable tools for comprehensively understanding nanoparticle-plant interactions. The reliance on multiple detection methods for data validation is emphasized to enhance the reliability of the research findings. The future outlooks of this field are explored, including the potential use of alternative introduction sites, such as stems, and the continued development of nanoparticle formulations that improve adhesion and penetration. By addressing these challenges and fostering multidisciplinary research, the field of nanoparticle transport in plants is poised to make significant contributions to sustainable agriculture and environmental management.

Recent advances and applications of laser-based imaging techniques in food crops and products: a critical review

To meet the growing demand for food quality and safety, there is a pressing need for fast and visible techniques to monitor the food crop and product production processing, and to understand the chemical changes that occur during these processes. Herein, the fundamental principles, instruments, and characteristics of three major laser-based imaging techniques (LBITs), namely, laser-induced breakdown spectroscopy, Raman spectroscopy, and laser ablation-inductively coupled plasma-mass spectrometry, are introduced. Additionally, the advances, challenges, and prospects for the application of LBITs in food crops and products are discussed. In recent years, LBITs have played a crucial role in mapping primary metabolites, secondary metabolites, nanoparticles, toxic metals, and mineral elements in food crops, as well as visualizing food adulteration, composition changes, pesticide residue, microbial contamination, and elements in food products. However, LBITs are still facing challenges in achieving accurate and sensitive quantification of compositions due to the complex sample matrix and minimal laser sampling quantity. Thus, further research is required to develop comprehensive data processing strategies and signal enhancement methods. With the continued development of imaging methods and equipment, LBITs have the potential to further explore chemical distribution mechanisms and ensure the safety and quality of food crops and products.

In-situ elemental quantitative imaging in plant leaves by LA-ICP-MS with matrix-matching external calibration

Due to the enormous interest in plants related to bioscience, environmental and toxicological research, analytical methods are expected with the ability of getting information on elemental transfer, distribution and contents in plants. In this work, a mixture of gelatin (GA) and hydroxypropyl methyl cellulose (HPMC) was prepared to simulate plant matrix, a method based on laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) with matrix-matching external calibration was proposed for direct quantification of multiple elements in plants. The composition of GA&HPMC substrate was optimized, such as the concentration of spiked nitric acid, the mass fraction of both GA and HPMC in the substrate and the mass ratio of GA: HPMC. After spiking elemental solution, coating the mixture onto a glass slide and drying overnight at room temperature, GA&HPMC substrate was obtained. The substrate obtained with GA: HPMC of 8: 2 was used to fabricate the standard series, which exhibited good elemental homogeneity and similar elemental signal intensities in LA-ICP-MS detection to that obtained for plant Certified Reference Material (CRM). CRMs of different plants including Citrus leaf (GBW10019), Tea (GBW07605), Beans (GBW10021) and Scallions (GBW10049) were further pressed into pellets and subjected to the proposed method, and the quantification accuracy was demonstrated. The limits of detections of this method were found to be 0.003 (Ce)-104 (Ca) μg g-1, with a wide linear range (0.01-10000 μg g-1) for 17 target elements. The application potential of the method was further demonstrated by performing elemental imaging in Trigonotis peduncularis leaves. Rapid in-situ quantitative imaging of Zn, Cu, Sr and Mn was achieved, and the elemental quantitative distributions were discussed. The constructed substrate helped direct elemental quantification in plants. It provided a powerful and efficient tool for the investigation of the distribution and transfer of elements in plants, favoring further exploration of elemental bioavailability, transport and toxicity mechanisms.

Nanomaterials biotransformation: In planta mechanisms of action

Research on engineered nanomaterials (ENMs) exposure has continued to expand rapidly, with a focus on uncovering the underlying mechanisms. The EU largely limits the number and the type of organisms that can be used for experimental testing through the 3R normative. There are different routes through which ENMs can enter the soil-plant system: this includes the agricultural application of sewage sludges, and the distribution of nano-enabled agrochemicals. However, a thorough understanding of the physiological and molecular implications of ENMs dispersion and chronic low-dose exposure remains elusive, thus requiring new evidence and a more mechanistic overview of pathways and major effectors involved in plants. Plants can offer a reliable alternative to conventional model systems to elucidate the concept of ENM biotransformation within tissues and organs, as a crucial step in understanding the mechanisms of ENM-organism interaction. To facilitate the understanding of the physico-chemical forms involved in plant response, synchrotron-based techniques have added new potential perspectives in studying the interactions between ENMs and biota. These techniques are providing new insights on the interactions between ENMs and biomolecules. The present review discusses the principal outcomes for ENMs after intake by plants, including possible routes of biotransformation which make their final fate less uncertain, and therefore require further investigation.

Imaging tools for plant nanobiotechnology

The successful application of nanobiotechnology in biomedicine has greatly changed the traditional way of diagnosis and treating of disease, and is promising for revolutionizing the traditional plant nanobiotechnology. Over the past few years, nanobiotechnology has increasingly expanded into plant research area. Nanomaterials can be designed as vectors for targeted delivery and controlled release of fertilizers, pesticides, herbicides, nucleotides, proteins, etc. Interestingly, nanomaterials with unique physical and chemical properties can directly affect plant growth and development; improve plant resistance to disease and stress; design as sensors in plant biology; and even be used for plant genetic engineering. Similarly, there have been concerns about the potential biological toxicity of nanomaterials. Selecting appropriate characterization methods will help understand how nanomaterials interact with plants and promote advances in plant nanobiotechnology. However, there are relatively few reviews of tools for characterizing nanomaterials in plant nanobiotechnology. In this review, we present relevant imaging tools that have been used in plant nanobiotechnology to monitor nanomaterial migration, interaction with and internalization into plants at three-dimensional lengths. Including: 1) Migration of nanomaterial into plant organs 2) Penetration of nanomaterial into plant tissues (iii)Internalization of nanomaterials by plant cells and interactions with plant subcellular structures. We compare the advantages and disadvantages of current characterization tools and propose future optimal characterization methods for plant nanobiotechnology.

X-ray fluorescence spectrometry for environmental analysis: Basic principles, instrumentation, applications and recent trends

In recent years, the conceptual advancement on green analytical chemistry (GAC) has moved in parallel with efforts to incorporate new screening or quantitative low-cost analytical tools to solve analytical problems. In this sense, the role of solid state techniques that allow the non-invasive analysis (or with a minimum sample treatment) of solid samples cannot be neglected. This review describes the basic principles, instrumentation and advances in the application of X-ray fluorescence instrumentation to the environmental sciences research topics, published between 2006 and 2020. Obviously, and because of the enormous number of works that can be found in the literature, it is not possible to exhaustively cover all published articles and the diversity of topics related to the environment in which a solid state technique like XRF has been applied successfully. It is a question of making a compilation of the instrumentation in use, the significant advances in XRF spectrometry and sample treatment strategies to highlight the potential of its implementation for environmental assessment.

Effects of La2O3 nanoparticles and bulk-La2O3 on the development of Pfaffia glomerata (Spreng.) Pedersen and respective nutrient element concentration

Nanoparticles (NPs) have been progressively applied in the last decades, which may impact the environment. Synthesis of pigments, growing, and nutrient element uptake by plants can also be affected by NPs. The influence of lanthanum oxide nanoparticles (La₂O₃ NPs) on growth, pigment synthesis, and nutrient element uptake by Pfaffia glomerata (Spreng.) Pedersen, a medicinal plant native in South America, was evaluated in the present study. P. glomerata plantlets were cultivated for 28 days in the absence (control) and presence of 100, 200, and 400 mg L^-1 of La₂O₃ NPs or bulk-La₂O₃ (b-La₂O₃) at the same cultivation conditions. Root development, aerial part growth, and pigment concentration in plants were affected by b-La₂O₃ and La₂O₃ NPs, mainly by La₂O₃ NPs. In spite of alteration of nutrient element concentration observed for the 100 and 200 mg L^-1 of La₂O₃ NPs or b-La₂O₃ treatments, Ca, Cu, Fe, K, La, Mg, Mn, Mo, P, S, and Zn determination in stems and leaves revealed drastically and similar decrease of these elements in plants cultivated in the presence of 400 mg L^-1 of La₂O₃ NPs or b-La₂O₃. Element distribution (mapping) determined by using laser ablation inductively coupled plasma mass spectrometry in leaves of plants submitted to treatment with 400 mg L^-1 of b-La₂O₃ or La₂O₃ NPs showed differences in the distribution of elements, indicating distinct effects of b-La₂O₃ and La₂O₃ NPs on P. glomerata. As such, this study demonstrated that La₂O₃ NPs may impact plant growth. However, more investigations are necessary for better understanding of the effect of La₂O₃ on plants, including a broader range of concentration.

Current Methods and Prospects for Analysis and Characterization of Nanomaterials in the Environment

Analysis and characterization of naturally occurring and engineered nanomaterials in the environment are critical for understanding their environmental behaviors and defining real exposure scenarios for environmental risk assessment. However, this is challenging primarily due to the low concentration, structural heterogeneity, and dynamic transformation of nanomaterials in complex environmental matrices. In this critical review, we first summarize sample pretreatment methods developed for separation and preconcentration of nanomaterials from environmental samples, including natural waters, wastewater, soils, sediments, and biological media. Then, we review the state-of-the-art microscopic, spectroscopic, mass spectrometric, electrochemical, and size-fractionation methods for determination of mass and number abundance, as well as the morphological, compositional, and structural properties of nanomaterials, with discussion on their advantages and limitations. Despite recent advances in detecting and characterizing nanomaterials in the environment, challenges remain to improve the analytical sensitivity and resolution and to expand the method applications. It is important to develop methods for simultaneous determination of multifaceted nanomaterial properties for in situ analysis and characterization of nanomaterials under dynamic environmental conditions and for detection of nanoscale contaminants of emerging concern (e.g., nanoplastics and biological nanoparticles), which will greatly facilitate the standardization of nanomaterial analysis and characterization methods for environmental samples.

Fate, bioaccumulation and toxicity of engineered nanomaterials in plants: Current challenges and future prospects

The main focus of this review is to discuss the current advancement in nano-metallic caused phytotoxicity on living organisms and current challenges in crops. Nanostructured materials provide new tools in agriculture to boost sustainable food production, but the main concern is that large-scale production and release of nanomaterials (NMs) into the ecosystem is a rising threat to the surrounding environment that is an urgent challenge to be addressed. The usage of NMs directly influences the transport pathways within plants, which directly relates to their stimulatory/ inhibitory effects. Because of the unregulated nanoparticles (NMs) exposure to soil, they are adsorbed at the root surface, followed by uptake and inter/intracellular mobility within the plant tissue, while the aerial exposure is taken up by foliage, mostly through cuticles, hydathodes, stigma, stomata, and trichomes, but the actual mode of NMs absorption into plants is still unclear. NMs-plant interactions may have stimulatory or inhibitory effects throughout their life cycle depending on their composition, size, concentration, and plant species. Although many publications on NMs interactions with plants have been reported, the knowledge on their uptake, translocation, and bioaccumulation is still a question to be addressed by the scientific community. One of the critical aspects that must be discovered and understood is detecting NMs in soil and the uptake mechanism in plants. Therefore, the nanopollution in plants has yet to be completely understood regarding its impact on plant health, making it yet another artificial environmental influence of unknown long-term consequences. The present review summarizes the uptake, translocation, and bioaccumulation of NMs in plants, focusing on their inhibitory effects and mechanisms involved within plants.

Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry Imaging in Biology

Elemental imaging gives insight into the fundamental chemical makeup of living organisms. Every cell on Earth is comprised of a complex and dynamic mixture of the chemical elements that define structure and function. Many disease states feature a disturbance in elemental homeostasis, and understanding how, and most importantly where, has driven the development of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) as the principal elemental imaging technique for biologists. This review provides an outline of ICP-MS technology, laser ablation cell designs, imaging workflows, and methods of quantification. Detailed examples of imaging applications including analyses of cancers, elemental uptake and accumulation, plant bioimaging, nanomaterials in the environment, and exposure science and neuroscience are presented and discussed. Recent incorporation of immunohistochemical workflows for imaging biomolecules, complementary and multimodal imaging techniques, and image processing methods is also reviewed.