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A single gem lithospheric diamond with five sulfide inclusions from the Udachnaya kimberlite (Siberia, Russia) has been analyzed non-destructively to track the growth conditions of the diamond. Sulfides are the most abundant mineral inclusions in many lithospheric diamond crystals and are the most favorable minerals to date diamond crystals by Re-Os isotope systematics. Our investigation used non-destructive, micro-techniques, combining X-ray tomography, X-ray fluorescence, X-ray powder diffraction, and Raman spectroscopy. This approach allowed us to determine the spatial distribution of the inclusions, their chemical and mineralogical composition on the microscale, and, finally, the paragenetic association, leaving the diamond host completely unaffected. The sample was also studied by X-ray diffraction topography to characterize the structural defects of the diamond and to obtain genetic information about its growth history. The X-ray topographic images show that the sample investigated exhibits plastic deformation. One set of {111} slip lamellae, corresponding to polysynthetic twinning, affects the entire sample. Chemical data on the inclusions still trapped within the diamond show they are monosulfide solid solutions of Fe, Ni and indicate a peridotitic paragenesis. Micro-X-ray diffraction reveals that the inclusions mainly consist of a polycrystalline aggregate of pentlandite and pyrrothite. A thorough analysis of the Raman data suggests the presence of a further Fe, Ni sulfide, never reported so far in diamonds: mackinawite. The total absence of any oxides in the sulfide assemblage clearly indicates that mackinawite is not simply a "late" alteration of pyrrhotite and pentlandite due to secondary oxidizing fluids entering diamond fractures after the diamond transport to the surface. Instead, it is likely formed as a low-temperature phase that grew in a closed system within the diamond host. It is possible that mackinawite is a more common phase in sulfide assemblages within diamond crystals than has previously been presumed, and that the percentage of mackinawite within a given sulfide assemblage could vary from diamond to diamond and from locality to locality. [ABSTRACT FROM AUTHOR]

Iron (Fe) sources available for plants in the rhizospheric solution are mainly a mixture of complexes between Fe and organic ligands, including phytosiderophores (PS) and water-extractable humic substances (WEHS). In comparison with the other Fe sources, Fe-WEHS are more efficiently used by plants, and experimental evidences show that Fe translocation contributes to this better response. On the other hand, very little is known on the mechanisms involved in Fe allocation in leaves. In this work, physiological and molecular processes involved in Fe distribution in leaves of Fe-deficient Cucumis sativus supplied with Fe-PS or Fe-WEHS up to 5 days were studied combining different techniques, such as radiochemical experiments, synchrotron micro X-ray fluorescence, real-time reverse transcription polymerase chain reaction and in situ hybridization. In Fe-WEHS-fed plants, Fe was rapidly (1 day) allocated into the leaf veins, and after 5 days, Fe was completely transferred into interveinal cells; moreover, the amount of accumulated Fe was much higher than with Fe-PS. This redistribution in Fe-WEHS plants was associated with an upregulation of genes encoding a ferricIII-chelate reductase (FRO), a Fe2+ transporter (IRT1) and a natural resistance-associated macrophage protein (NRAMP). The localization of FRO and IRT1 transcripts next to the midveins, beside that of NRAMP in the interveinal area, may suggest a rapid and efficient response induced by the presence of Fe-WEHS in the extra-radical solution for the allocation in leaves of high amounts of Fe. In conclusion, Fe is more efficiently used when chelated to WEHS than PS and seems to involve Fe distribution and gene regulation of Fe acquisition mechanisms operating in leaves. [ABSTRACT FROM AUTHOR]

A clean and cheap procedure for the synthesis of zeolites is presented, using glass and aluminum wastes as starting materials. The products are aluminosilicate materials with a high cation exchange capacity (CEC: 259-389.5 meq/100 g) containing 25-30% of crystalline zeolites. Since the synthesized materials are free of potentially toxic elements, they could be safely used for environmental and agricultural applications. More specifically, a material containing 30% of zeolite A has been synthesized at 60°C in one week, using NaOH as mineralizing agent. About 15% of zeolite A has been obtained at room temperature in six months. When KOH was employed, 25% of edingtonite has been produced in the final material after one week at 90°C. All the materials have been characterized for crystallinity, crystal morphology, particle size, pore size, surface area, and CEC. The whole process has been designed with the aim to recycle useful waste materials and reduce at minimum energy consumption and the production of harmful greenhouse gases. [ABSTRACT FROM AUTHOR]

Four different coal fly ashes have been characterized for their potential application in the synthesis of Zeolite X for its use as cation exchanger for the remediation of heavy metal-polluted soils. Their chemical composition, with particular attention to the concentration of trace elements potentially toxic for the environment, has been determined by total dissolution and ICP-OES analysis. The relative amount of Zeolite X synthesized after 4 days of incubation at 60 °C starting from fly ash and the possible synthesis of other minerals has been investigated by means of X-ray diffraction. The fly ashes have been evaluated by their morphology (SEM analysis), granulometry (laser granulometry) and loss on ignition (L.O.I.). Moreover, the fraction of potentially toxic elements, such as As, Cd, Cr, Cu, Pb and Zn, which can be released in solution during the synthetic process, has been quantified. Among the coal fly ash varieties analyzed, one resulted to possess suitable properties for the synthesis of environmentally applicable Zeolite X, since it showed higher yield, no by-products, lower mean particle size (useful for a quicker dissolution of the ash), and very low concentrations of potentially toxic elements. Finally, this coal fly ash has been fully characterized with regards to its chemical composition (major and minor constituents) by total dissolution and ICP-OES analysis, but also X-ray fluorescence of its fused powder. [ABSTRACT FROM AUTHOR]

In the last years, uncontrolled fires are frequently occurring in forest and agricultural areas as an indirect effect of the rising aridity and global warming or caused by intentional illegal burnings. In addition, controlled burning is still largely used by farmers as an agricultural practice in many parts of the world. During fire events, soil can reach very high temperatures at the soil surface, causing dramatic changes of soil properties and elements biogeochemistry. Among soil elements, also potentially toxic elements (PTEs) can be affected by fires, becoming more or less mobile and bioavailable, depending on fire severity and soil characteristics. Such transformations could be particularly relevant in agricultural soils used for crop productions since fire events could modify PTEs speciation and uptake by plants and associated (micro)organisms thus endangering the whole food-chain. In this review, after describing the effects of fire on soil minerals and organic matter, the impact of fires on PTEs distribution and speciation in soils is presented, as well as their influence on soil microorganisms and plants uptake. The most common experimental methods used to simulate fires at the laboratory and field scale are briefly illustrated, and finally the impact that traditional and innovative agricultural practices can have on PTEs availability in burned agricultural soils is discussed in a future research perspective. [Display omitted] • Fires threaten not only forest ecosystems but also agricultural environments. • Fire affects soil organic matter and soil minerals and associated PTEs. • Fire impacts microbial communities and the soil-plant system affecting PTEs uptake. • Fire could promote the transfer of PTEs from soil through the food chain. • In burned soils, agronomic practices can either reduce or increase PTEs availability. [ABSTRACT FROM AUTHOR]

Fe3O4/CeO2 nanocomposites were synthetized by coating magnetite seeds of different morphologies (hexagonal, spheroidal, quasi-spherical) with ceria, in ethylene glycol as solvothermal solvent. The synthesis was performed in the presence of microwave irradiation aiming to overcome the common disadvantages proper of the classic solvothermal/hydrothermal procedure. The obtained nanocomposites were calcined at the optimum temperature of 550 °C. The structure of the new nanomaterials was carefully investigated by IR, XRD, SEM, EDS and TEM analyses. The nanocomposites resulted to be constituted by CeO2 nanoparticles distributed onto Fe3O4 seeds, that kept their pristine morphology. The new materials were used as catalysts for imine synthesis from benzyl alcohol and aniline. The highest imine conversion rate was obtained with Fe3O4/CeO2, which was synthesized from Fe3O4 nanoparticles (hexagonal) obtained by microwave hydrothermal procedure in the absence of any organic additive (polyvinylpyrrolidone, trisodium citrate dihydrate or oleic acid). The catalyst could be easily removed from the reaction mixture with the help of an external magnet, and it was recycled for at least five runs with increasing catalytic activity. [ABSTRACT FROM AUTHOR]

The study evaluated the rheological properties and volatile profile of emulsion filled gels (EFG) composed of inulin, dry-fractionated proteins of red lentil (RL) and black chickpea (BC), and containing three percentages of sunflower seed oil (5%, 10% and 15%). The EFG were then used as fat replacers in the formulation of low-fat brioches. The EFG showed shear thinning behavior, and the EFG containing 15% oil was found to have the highest consistency index. EFG viscosity and viscoelasticity were significantly affected by RL and BC, oil concentration and storage (4 °C for 24 h). EFG made using BC was selected for vegan brioche production due to its lower concentration of undesirable volatile compounds linked to pulse flavor. All the vegan brioches obtained met the criteria for labeling as "low-fat" (Regulation (EC) No 1924/2006). The use of EFG reduced total porosity and pore connectivity but increased hardness and chewiness. The brioche made with EFG containing 15% oil had the lowest levels of hardness and chewiness, and was most similar to the control in its volatile profile and typical brioche odor. These results indicate that EFG containing 15% oil has the potential to replace fat in the production of vegan brioches. [Display omitted] • Viscosity and viscoelasticity of the EFG were affected by type of protein, oil concentration and storage. • EFG can be used as fat replacer to obtain "low-fat" brioches. • The use of EFG with 15% of oil determined a lower hardness of vegan brioches. • EFG affected the sensory properties in terms of color and texture. [ABSTRACT FROM AUTHOR]

Northern Apulia has primary and secondary chert sources which were exploited in prehistory. During Neolithic period, on the north-eastern coast of the Gargano promontory, an important network of mines represented one of the most significant primary chert sources in the Adriatic area. However, easily accessible secondary chert sources are available in the Tavoliere plain in several synthems from the southern Appennines chain to the Gulf of Manfredonia. This work provides an overview of chert sources distributed in the Gargano and Tavoliere plain by means of a combination of up-to-date geological and archaeological information. Moreover, the lithic industries of eight Early and Middle Neolithic settlements were sampled in order to understand the procurement strategies of chert or tools used by communities settled in the Tavoliere plain. A non-destructive multi-parametric protocol for chert investigations (NM-PCI) method was applied to all the collected Gargano mines and secondary chert from the Tavoliere area. The results obtained demonstrate a high percentage of secondary chert used in the investigated sites, and the exploitation of mined chert essentially for the production of blades. In this latter case, provenance from the mines of Maiolica Fm is more frequent than that from mines of Peschici Fm. The polygenic nature of the pebbles occurring in the different synthems is the consequence of different sedimentary histories, as witnessed by the difference in the lithological array between inland and coastal synthems, and makes difficult any attribution to a specific source. If on the one hand these results further testify the circulation of mined Gargano chert in the Tavoliere plain in the Early Neolithic, on the other hand they demonstrate that the secondary coastal pebbles, especially those of southern Gargano lithotypes, were largely used, even in inland settlements. Moreover, these results suggest the exploitation of other primary cherts of the southern Gargano. This underlines the importance of further archaeological and geological investigations to better understand the exploitation and circulation of chert in Northern Apulia and in the Adriatic area. [ABSTRACT FROM AUTHOR]

Total-reflection X-ray fluorescence (TXRF) is a well-established atomic spectroscopy technique used for the elemental characterization of different kinds of matrixes in several fields. Previous works demonstrated its applicability for the elemental quantification of aluminosilicates and, in particular, clays. However, one of the limits of the previously developed methods was the detection and quantification of light elements, in particular for those elements with an atomic number (Z) below 13 (Al). In the present work a new TXRF-based analytical method for the quantification of light elements in aluminosilicate materials is described, using an in-house built Low-Z TXRF spectrometer equipped with a Cr source, a multilayer monochromator, an SDD detector equipped with an ultrathin Si 3 N 4 window and a vacuum chamber. Samples were prepared as simple slurries (dispersing 50 mg of powder into 2.5 mL of 1%-Triton X-100 water solution and adding Ag as internal standard) and 10 μL were deposited onto a quartz carrier and dried before the analysis. Light elements such as F, Na and Mg were quantified with a limit of detection of 682, 260 and 133 mg/kg, respectively. Carbon and oxygen could also be detected. The new method allowed a complete analysis of major elements in aluminosilicates from F to Fe. The method showed a good accuracy in the range of 80–120% and the results agreed with the data obtained with a commercial TXRF spectrometer (for elements >13) and WDXRF, employed as reference methods. Despite a lower precision in respect to WDXRF, in some samples the quantification of F was possible only by using the Low-Z TXRF spectrometer. Finally, the method demonstrated to be suitable for the analysis of aluminosilicates, in particular when low amounts of sample (few milligrams) are available. • Light elements are quantified for the first time in in aluminosilicates complex matrix with TXRF. • Fluorine is quantified with a limit of detection of 682 mg/kg. • Easy sample preparation: 50 mg of sample suspended in 2.5 mL of 1% Triton X-100 water solution. • Good accuracy with a recovery in the range 80–120% for elements from F to Fe. • Carbon and oxygen detection in aluminosilicates. [ABSTRACT FROM AUTHOR]

• First map of primary and secondary chert sources in nothern Apulia. • Multivariate statistics applied to a compositional mixed dataset of chert. • Peschici Fm. mines were better differentiated than Maiolica Fm. ones. • Polygenic secondary chert sources of Tavoliere mirror the Appenine and Gargano origin. During the Neolithic period, near the North-Eastern coast of the Gargano promontory (Apulia Region, Italy), an important network of mines represented the most ancient European example of systematic exploitation of primary chert sources. These high-quality raw materials were traded between prehistoric communities living on both sides of the Adriatic Sea. However, the Gargano promontory is not the only area of the Apulia Region with chert sources. Secondary sources of the Tavoliere plain deposits and primary sources of the Southern Apennines must be considered in addition to the Gargano chert-bearing limestones. This paper provides an overview of chert sources distribution in the Gargano and Tavoliere plain through a chert sources map based on up-to-date geological and archaeological information. The map represents the first lithic procurement mapping in the Region and it is a very useful tool for planning sampling activities and detect the potential chert sources exploited in Neolithic times. The map was used for sampling pebbles near the coast and inland of the investigated area. A non-destructive multi-parametric protocol for chert investigations (NM-PCI) method was applied to all the collected secondary samples. The results were compared at first with those of the Gargano mines. The output of the partition around medoids (PAM) procedure shows, as a general trend, that primary sources are well grouped, while secondary sources show less clear compositional fingerprints. However, the features of the coastal and inland pebbles are quite different. [ABSTRACT FROM AUTHOR]

Plant viruses can affect micro- and macro-nutrients homeostasis in woody plants, with fluctuation in the concentration of some elements at the leaf level due to the pathogen activity and/or the plant physiological response to the infection.Leaves of Fraxinus ornus L. (flowering ash) were sampled for three consecutive years in the city of Hamburg (Germany), from both trees showing the typical symptoms of the ash shoestring associated virus infection (ASaV+) and healthy trees (ASaV-). Such leaves were analyzed by μ-XRF, using both laboratory and synchrotron X-ray sources, and large differences between symptomatic and not symptomatic leaves were observed: ASaV+ samples showed uneven element distribution and regions of the lamina with severe depletions of P, S, and Ca. Differently, K appeared more concentrated. Thus, 139 leaflets sampled from various healthy and infected ash trees over the three-year period were analyzed for K and Ca concentration with a portable XRF instrument. We found that the K:Ca concentration ratio was always significantly higher in ASaV+ samples, and this trend was verified for all the samplings over the tree years. We conclude that the K:Ca ratio parameter has potential in the frame of trendsetting diagnostics and could be used, together with visual symptoms, for a rapid, non-destructive, on-site and cheap indirect ASaV detection. [Display omitted] • μXRF shows differences in elements homeostasis between healthy and ASaV infected leaves. • K and Ca concentration in leaves correlate with ASaV infection in Fraxinus ornus L. • P-XRF and K:Ca ratio can be used for the early in-situ ASaV infection detection. [ABSTRACT FROM AUTHOR]

[Display omitted] • 24 genotypes of bean grown on 2 different sites were studied to trace their origin. • A method for the elemental analysis of legumes with TXRF was developed. • Both quantitative and spectral data were analysed with multivariate methods. • The use of PLS-DA with SNV-GLSW on TXRF spectra allow to classify the beans origin. • TXRF spectra were used as food fingerprint to trace its geographical origin. The increased costumers' request of safe and high-quality food products makes food traceability a priority for frauds identification and quality certification. Elemental profiling is one of the strategies used for food traceability, and TXRF spectroscopy is widely used in food analysis even if its potentialities have not been fully investigated. In this work, a new method for food traceability using directly TXRF spectra coupled with multivariate analyses, was tested. Twenty-four different beans' genotypes (Phaseolus vulgaris L.) grown onto two different sites have been studied. After the development of the method for beans' analysis, TXRF spectra were collected and processed with PCA combined with SNV and GLSW filter obtaining a perfect clustering of the seeds according to their geographical origin. Finally, using PLS-DA, beans were correctly classified demonstrating that TXRF spectra can be successfully used as fingerprint for food/seed traceability and that elemental quantification procedure is not necessary to this aim. [ABSTRACT FROM AUTHOR]

Controlled or accidental fires can impact agricultural soils amended with composted organic materials since high temperatures cause fast organic matter (OM) mineralization and soil properties modifications. During these events, potentially toxic elements (PTEs) associated with OM can be released and change their distribution and speciation thus becoming a threat to the environment and to crops. In this study, we investigated the changes of distribution and speciation of chromium in soils long-term amended with compost obtained from tannery sludges, after simulating fires of different intensity (300, 400 and 500 °C) likely to occur on agricultural soils. A combination of conventional soil chemical analyses and bulk and (sub)micro X-ray analyses allowed the observation of the formation of hexavalent chromium and changes of chromium speciation. Specifically, a strong decrease of Cr-OM associations was found with increasing temperature in favour of Cr-iron (hydr)oxides interactions and CaCrO 4 formation. These data provide first evidence that fires can transform OM-stabilized Cr into more mobile, available and toxic Cr-forms potentially accessible for plant uptake, thus posing a risk for the food chain and the environment. [Display omitted] • Agricultural soils amended with tannery waste represent a threat to the environment. • Fires can mineralize soil organic matter (SOM) and modify Cr speciation. • The Cr previously associated to SOM is partly redistributed on iron (hydr)oxides. • A small but significant fraction of Cr(III) is oxidized to CaCrO 4. • The newly formed Cr species are potentially accessible for plant uptake. [ABSTRACT FROM AUTHOR]

• Soil aggregates were studied by SEM-EDX hyperspectral data analysis. • Datamuncher Gamma software was implemented to manage SEM-EDX data cubes. • Soil phases were identified on the base of net element intensity correlations. • Aggregates of natural and anthropic origin were distinguished using element biplots. • The Cr/Fe ratio allowed to identify different types of polluted soil aggregates. Scanning electron microscopy coupled with microanalysis (SEM-EDX) is an important analytical tool for the morphological and chemical characterization of different types of materials. In many applications, SEM-EDX elemental maps are usually used and processed as images, thus flattening and reducing the spectroscopic information contained in EDX hyperspectral data cubes. The exploitation of the full hyperspectral dataset could be indeed very useful for the study of complex matrices like soil. In order to maximize the information attainable by SEM-EDX data cubes analysis, the software package "Datamuncher Gamma" was implemented and applied to study soil aggregates. By using this approach, different phases (silicates, aluminosilicates, Ca-carbonates, Ca-phosphates, organic matter, iron oxides) inside soil aggregates were successfully identified and segmented. The advantages of this method over the common ROI imaging approach are presented. Finally, this method was used to compare different aggregates in a Cr-polluted soil and understand their possible pedological history. The present method can be used for the analysis of every type of SEM-EDX data cubes, allowing its application to different types of samples and fields of study. [ABSTRACT FROM AUTHOR]

Phytoremediation can be a promising and sustainable strategy to recovery Potentially Toxic Elements (PTEs) contaminated soils. However, at the field level, this tool can be limited by many issues. Herein, we combined native plant species with different cover type (mono and poly culture) in an in-field mesocosm experiment for the remediation of multi-contaminated soils from Bagnoli brownfield site (Southern Italy). We preliminary gain insights about the physical, chemical and biological features of the soils and subsequently induced a potential variation in the soil microbiome. We found that polyculture better respond both in terms of pollutant phytostabilization efficiency and from a stress tolerance perspective. Among plant species, Festuca achieved the best performance due to the overexpression of metal transporters able in both PTEs influx and sequestration from the cytoplasm. We achieved a site-specific bio-factory, which represents a strategy for the sustainable and relatively fast recovery of large contaminated areas. [Display omitted] • Native plants were combined with different cover types (mono and polyculture). • We found plants able to phytostabilize PTEs and positively respond to PTEs stress. • Festuca achieved the best performance due to metal transporters overexpression. • A site-specific bio-factory is a sustainable fast technology for soil remediation. [ABSTRACT FROM AUTHOR]

This work presents a study on the fracturing behaviour of a quartz tempered clay-based ceramic subjected to damage in freeze-thaw cycles. X-ray micro-computed tomography (micro-CT) provided high-resolution imaging of the ceramic before and during the freeze-thaw treatment, allowing to analyse a fully water-saturated sample using a special thermal stage designed to keep the sample frozen during analyses. Micro-CT 3D renderings showed the internal features of the specimen (i.e., quartz grain distribution), the increment of fracture count and size, and the detachment of ceramic and/or temper fragments from the edges of the sample over the cycles. Selected 2D micrographs, before and after freeze-thawing treatment, were analysed using the MATLAB toolbox FracPaQ. This software provided detailed data on fracture length, intensity, density, orientation and connectivity, and enabled to interpret the process of fracture initiation and propagation inside the material. These results showed that the temper plays a crucial role in ceramic fracturing behaviour under freeze-thawing conditions, as damage propagation is influenced by quartz grain distribution and orientation within the material. The study described in this work, not only offers new insights into the fracture dynamics of freeze-thawed clay-based ceramics, but also presents a new methodological approach to quantitatively measure fracture damage in porous materials. [Display omitted] • μ-CT with cooling stage was used to study freeze-thawing effects in clay-based ceramic. • μ-CT allowed to investigate formation and evolution of fractures within the material. • Image analysis of HR micrographs was performed using FracPaQ software toolbox. • μ-CT rendering and FracPaQ provided exhaustive descriptions of fracturing process. [ABSTRACT FROM AUTHOR]

The combined potentiality of benchtop micro X-ray fluorescence spectroscopy (μ-XRF) and micro computed tomography (μ-CT) has been applied to describe microstructures, type and distribution of mineralogical phases as well as geological constraints on the history of the North West Africa (NWA) 8657 shergottite Martian meteorite. The 3D rendering of the sample was used to compute its vesiculation, infer the presence of cracks and reveal different shapes in its crystal habits including subhedral pyroxene phases and rounded sulphide and/or sulphates minerals. Phase discrimination was achieved by comparing chemical information about element distribution with mineral classes segmented as a function of their relative density. In particular, the relationships between the plagioclase/maskelynite phase and other minerals such as Ca-phosphates, the chemical zoning of Ca-pyroxenes and maskelynite and the presence of S-bearing phases in the form of K-sulphates and Fe-sulphides were revealed, which allowed reconstructing satisfactorily meteorite history. The successful performance of the combined approach used in this work shows promising for further application to other types of meteorites. Image 1 • μ-XRF and μ-CT were combined to describe the mineralogy and microstructures of the NWA 8657 Martian meteorite. • μ-XRF and μ-CT allowed a non-invasive approach in mapping the spatial distribution of elements. • μ-XRF and μ-CT were able to provide and unveil the processes involved in the meteorite formation. [ABSTRACT FROM AUTHOR]

The research on meteorites from hot and cold deserts is gaining advantages from the recent improvements of portable technologies such as X-ray fluorescence spectroscopy (XRF). The main advantages of portable instruments include the fast recognition of meteorites through their classification in macro-groups and discrimination from materials such as industrial slags, desert varnish covered rocks and iron oxides, named "meteor-wrongs". In this study, 18 meteorite samples of different nature and origin were discriminated and preliminarily classified into characteristic macro-groups: iron meteorites, stony meteorites and meteor-wrongs, combining a portable energy dispersive XRF instrument (pED-XRF), principal component analysis (PCA) and some machine learning algorithms applied to the XRF spectra. The results showed that 100% accuracy in sample classification was obtained by applying the cubic support vector machine (CSVM), fine kernel nearest neighbor (FKNN), subspace discriminant-ensemble classifiers (SD-EC) and subspace discriminant KNN-EC (SKNN-EC) algorithms on standardized spectra. Image 1 • pED-XRF analysis were used to discriminate and classify between meteorites and meteor-wrongs. • PCA of the whole pED-XRF spectrum was used to find the class clusterization in the scores plot. • Five types of machine learning algorithms were tested to classify the samples into macro-groups. [ABSTRACT FROM AUTHOR]

Cesiumlead-halide perovskite nanocrystals are an emerging class of materials which potentially have different applications due to the several physical properties they exhibit. These properties are strongly dependent on the elemental composition of the nanocrystals and, to date, only few methods are available for their chemical analysis, such as scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX). The present work aims at establishing a new, fast and simple method for the elemental analysis of cesium lead-halide perovskite nanocrystals exploiting total-reflection x-ray fluorescence (TXRF) spectroscopy. The method was validated using a synthetized set of samples and comparing the TXRF results with SEM-EDX data. The sample preparation consisted in suspending the perovskites in 2.0 ml of hexane and sampling 10 μl of the suspension for deposition on a preheated quartz carrier. The element recovery ranged between 82% and 118% for mixed-halide perovskites, while for single halide perovskites it improved to 86%–105%. The present method can be implemented and used also for the elemental characterization of other types of perovskite nanocrystals. Unlabelled Image • Elemental analysis of cesium lead-halide perovskite NCs is performed by TXRF. • Sample preparation consists only in suspending NCs in hexane. • TXRF results are comparable to those obtained by SEM-EDX (reference method). • This method can be potentially used for the analysis of other perovskite NCs. • This method is simple, cheap and fast, compared to other analytical techniques. [ABSTRACT FROM AUTHOR]

Surface display of functional groups with specific reactivity around living cells is an emerging, low cost and highly eco-compatible technology that serves multiple applications, ranging from basic biochemical studies to biomedicine, therapeutics and environmental sciences. Conversely to classical methods exploiting hazardous organic synthesis of precursors or monovalent functionalization via genetics, here we perform functional decoration of individual living microalgae using suitable biocoatings based on polydopamine, a melanin-like synthetic polymer. Here we demonstrate the one-pot synthesis of a functional polydopamine bearing phenylboronic units which can decorate the living cell surfaces via a direct ester formation between boronic units and surface glycoproteins. Furthermore, biosorption of fluorescent sugars on functionalized cell membranes is triggered, demonstrating that these organic coatings act as biocompatible soft shells, still functional and reactive after cell engineering., (© 2024. The Author(s).)