I14-Hard X-ray Nanoprobe
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Diamond Proposal Number(s):
[38366]
Open Access
Abstract: Spectro-microscopy is an experimental technique which can be used to observe spatial variations in chemical state and changes in chemical state over time or under experimental conditions. As a result it has broad applications across areas such as energy materials, catalysis, environmental science and biological samples. However, the technique is often limited by factors such as long acquisition times and radiation damage. We present two measurement strategies that allow for significantly shorter experiment times and total doses applied. The strategies are based on taking only a small subset of all the measurements (e.g. sparse acquisition or subsampling), and then computationally reconstructing all unobserved measurements using mathematical techniques. The methods are data-driven, using spectral and spatial importance subsampling distributions to identify important measurements. As a result, taking as little as 4–6% of the measurements is sufficient to capture the same information as in a conventional scan.
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Sep 2026
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I18-Microfocus Spectroscopy
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Open Access
Abstract: Predicting steel corrosion in porous media – e.g. soil, bentonite, concrete – remains challenging due to the limited understanding of the precipitation and evolution of corrosion products under realistic conditions. To shed light on these processes, we investigate the long-term temporal and spatial evolution of iron (hydr)oxides at the pore-scale, employing in-situ synchrotron-based chemical imaging including X-ray fluorescence, X-ray diffraction, X-ray absorption spectroscopy, and absorption contrast. A pore is simulated in a 300 μm diameter capillary, containing iron and stagnant electrolyte, and is aged for up to 2.7 years. The electrolyte is buffered at pH 8, with HCO3-, Cl-, and SO42- ions, both under aerobic and near-anaerobic conditions. Results show that, in electrolytes containing HCO3-, ferrihydrite initially formed remotely from the iron and transformed into goethite over time. In the long-term, mixed-valence green rust and magnetite formed near the iron. The spatial distribution and oxidation states of corrosion products can be rationalized using a reactive transport conceptual framework: Fe(II) and O2 release or consumption in electrochemical, diffusion, oxidation and additional reactions determine the concentration profiles and hence the location and time when corrosion products precipitate. Electrolyte composition – Cl- and SO42- – further influences which corrosion product is formed and stabilized over a certain time (e.g. green rust and lepidocrocite). Our findings demonstrate preferential precipitation on pore walls and far from the iron, with prolonged green rust stability, showcasing the relevance of investigating iron (hydr)oxides in realistic pore models. These insights improve predictions of corrosion product evolution, pore clogging, and stresses in porous media.
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Jul 2026
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B18-Core EXAFS
I18-Microfocus Spectroscopy
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Swaroop
Chakraborty
,
Iuliia
Mikulska
,
Rhiannon
Boseley
,
Sang
Pham
,
Prathmesh
Bhadane
,
Pankti
Dhumal
,
Santanu
Majumder
,
Jajati
Mandal
,
Tina
Geraki
,
Superb K.
Misra
,
Christian
Pfrang
,
Iseult
Lynch
Diamond Proposal Number(s):
[33674, 35117, 41674]
Open Access
Abstract: Metal–organic frameworks (MOFs) are increasingly deployed in environmental technologies, yet their fate and hazard under realistic multistep exposure scenarios remain poorly constrained. Here, we track hierarchical transformations of nanoscale ZIF-8 (Zeolitic Imidazolate Framework-8) across an exposure cascade spanning atmospheric aging (air and reactive gases O3/NO2), aqueous aging in environmentally and biologically relevant media, and ingestion by the freshwater crustacean Daphnia magna. Synchrotron Zn K-edge X-ray absorption spectroscopy (XAS), micro-X-ray fluorescence (μ-XRF), X-ray photoelectron spectroscopy (XPS), and electron microscopy show that gas-phase exposure produces only minor surface perturbations, whereas aqueous contact drives pronounced medium-dependent restructuring, including nitrogen depletion and oxygen enrichment at the surface and time-resolved dissolved Zn release with chemistry-imposed plateaus. In vivo, Zn speciation diverges from the pristine Zn–N fingerprint; an unexposed endogenous Zn baseline and linear combination fitting (LCF) indicate a mixture of endogenous Zn with transformed Zn pools dominated by O/P/S-type coordination environments. Acute ecotoxicity assay demonstrates strong concentration dependence (48 h immobilization EC50 ≈0.5 μg mL–1), and chronic exposure at 0.10 μg mL–1 reduces cumulative brood production with increased adult mortality over 24 days. Mechanistically, fractionated toxicity assays show that washed aged particles/precipitates and whole aged suspensions are more potent than particle-free filtrates, indicating that particle-associated transformed Zn pools contribute substantially beyond dissolved Zn alone. Together, these results show that ZIF-8 risk emerges from its sequential transformation trajectory rather than its pristine state, motivating tiered aging protocols coupled to in vivo speciation and fractionated hazard testing for MOF safety assessment.
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May 2026
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I18-Microfocus Spectroscopy
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Tamar
Hodos
,
Sally
Waite
,
Andrew
Parkin
,
Eline
Van Asperen
,
Vanessa
Boschloos
,
Hendrik
Hameeuw
,
Thomas
Delbey
,
Konstantin
Ignatyev
,
Christopher
Jones
,
Dave
Megson-Smith
,
Peter G.
Marten
Diamond Proposal Number(s):
[32888]
Open Access
Abstract: Local and regional museums often rely on cost-effective handheld equipment to undertake non-destructive pigment assessment. When preserved colourants are only microscopic, however, these methods’ limits may be encountered. This becomes acute with fragile objects, as is often the case for organic materials. Using a reconstructed decorated ostrich eggshell vessel, an elite grave good in 7th–6th C BCE Etruria, this study compares the efficacy of portable X-ray fluorescence spectrometry; handheld Fourier-transform infrared spectroscopy; Raman spectroscopy; visible-induced luminescence imaging; multispectral multi-light reflectance analysis; synchrotron radiation X-ray fluorescence; and X-ray absorption near edge structure analysis to distinguish microscopic pigment traces. The portable device results were inconclusive, but Egyptian blue and malachite were positively identified via synchrotron analyses. This outcome supports museums to further develop protocols regarding minimal pigment residue identifications on fragile objects, including assessing risk with external analysis, and informs our understanding of pigments used on organic objects during this period.
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May 2026
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I14-Hard X-ray Nanoprobe
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Diamond Proposal Number(s):
[38439]
Open Access
Abstract: Nanoplastics (NPls) have been recognized as emerging persistent toxic particulates in aquatic environments and their interactions with biota pose growing ecological concerns. Yet, the mechanisms governing their cellular association and resulting toxicity remain poorly resolved because population-level assays obscure the inherent variability among individual cells. Here, we integrate single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) with Gaussian mixture modelling (GMM) to quantify the dynamic heterogeneous association of Eu-doped polystyrene nanoplastics (Eu-doped NPls) with the model microalga Chlorella vulgaris. The GMM analysis identified distinct subpopulations exhibiting variable particle association that shift dynamically with exposure time and concentration. Across exposures of 5–20 mg L−1, GMM analysis revealed that the majority of microalgal cells (35–65%) belonged to low-association clusters, whereas only a small fraction (0–10%) exhibited high NPls association, with pronounced temporal and concentration-dependent shifts in subpopulation structure. A generalized linear model (GLM) further demonstrated that these high-burden subpopulations disproportionately account for observed growth inhibition, increasing from 12.75% at 5 mg L−1 to 39.34% and 43.05% at 10 and 20 mg L−1, respectively. Synchrotron-based nano X-ray fluorescence (nano-XRF) provided spatial evidence consistent with particle localization within or closely associated with algal cell, while physiological endpoints (chlorophyll-a content, CO2 fixation, ROS, and MDA levels) validated the toxicity trends. This integrative single-cell and unsupervised machine-learning modelling framework provides quantitative evidence that stochastic, heterogeneous interactions underpin NPls toxicity in microalgae. The approach offers a transferable analytical paradigm for elucidating the fate and effects of persistent plastic pollutants in aquatic ecosystems.
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Apr 2026
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I14-Hard X-ray Nanoprobe
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Diamond Proposal Number(s):
[33156]
Abstract: This thesis explores the design and reactivity of novel flavin-metal conjugates, hypothesizing that covalently tethering a redox-active isoalloxazine core to a transition metal overcomes diffusion-controlled kinetic limitations through proximal positioning. To validate the approach, three distinct metallic platforms—Pt(IV), Ru(IV), and Ir(I)—were conjugated to functionalized riboflavin derivatives and systematically investigated. First, linking flavins to Pt(IV) anticancer prodrugs enabled their rapid, reduction to bioactive Pt(II) species using endogenous electron donors, demonstrating superior efficacy compared to controls. Second, a cyclopentadienyl Ru(IV) quinoline scaffold was employed to create a bioorthogonal catalyst that successfully oxidized glutathione with enhanced redox reversibility, simultaneously mediating the activation of Pt(IV) substrates. Third, the strategy was expanded into classical homogeneous catalysis via a Ir(I)-flavin complex, providing a proof-of-concept for the synergistic activation of molecular hydrogen and subsequent intramolecular electron transfer. Across all systems, the covalent linkage proved essential. Ultimately, this work establishes a robust foundation for the rational design of dual-function bio-organometallic agents, paving the way for advanced redox-mediated chemotherapy and sustainable chemical synthesis.
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Apr 2026
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I14-Hard X-ray Nanoprobe
I18-Microfocus Spectroscopy
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Diamond Proposal Number(s):
[39618, 39938, 302085, 31588, 5116, 36811]
Open Access
Abstract: Correlative microscopy linking synchrotron X-ray fluorescence (SXRF) with optical imaging is valuable for contextualizing chemical element distributions in biology. The spatial correlation necessary to achieve this presents fundamental challenges and can be a significant constraint on accuracy and data interpretation. We present a technical solution based on a finder grid concept, optimized for SXRF correlative studies of metals in biological tissues, with scope for wider adaptation and application. A hierarchically patterned fiducial system was directly etched onto spectroscopically clean quartz substrates via femtosecond laser ablation. This design enables improved correlation among SXRF, optical imaging, and histological staining over a greater range of length scales than conventional registration methods such as the use of tissue architecture from serial sections and the use of electron-microscopy-resolution finder grids and applied fiduciary markers that can introduce XRF-signal-dominating levels of elements such as copper, nickel, gold, and titanium. We present two quartz finder grid formats: a microgrid and a nanogrid design. We demonstrate their utility for rapid ROI relocalization and same-section correlative workflows using human brain tissue. The etched quartz finder grid approach facilitates rapid and reproducible ROI relocalization and alignment across instruments, particularly where integral fiducial markers are sparse or ambiguous.
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Mar 2026
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I18-Microfocus Spectroscopy
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Diamond Proposal Number(s):
[36744]
Open Access
Abstract: The integration of nanoencapsulation techniques with foliar application presents a promising approach to enhance selenium (Se) biofortification in agriculture. This study examined the foliar uptake of liposome-encapsulated Se in wheat leaves (Triticum aestivum) using synchrotron-based micro-X-ray fluorescence (μ-XRF) and confocal microscopy. μ-XRF mapping showed Se accumulation at leaf edges after 24 h, suggesting initial uptake via stomata, while free Se was absorbed and transported more rapidly, highlighting the slow-release effect provided by liposomal encapsulation, longer than the analyzed time. No immediate translocation of Se to the stem was observed, suggesting that more time is required for this internal movement. Micro-X-ray absorption near-edge structure (μ-XANES) speciation analysis demonstrated that Se was metabolized into organic forms within the plant. Finally, confocal fluorescence microscopy confirmed liposome absorption through the plant surface within 24 h, corroborating the μ-XRF findings. These results are crucial for optimizing liposome formulation to maximize Se transfer to edible parts.
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Mar 2026
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I18-Microfocus Spectroscopy
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Open Access
Abstract: Understanding the impact of volcanic eruptions on climate over the last two millennia is essential to place current anthropogenic climate change into a long-term context. High-resolution proxy archives are crucial for this purpose, yet their availability decreases rapidly back in time. Besides ice cores, speleothems and corals, tree rings represent a uniquely valuable archive, providing records with annual resolution of past-climate change. Volcanic eruptions are among the most impactful natural forcings on Earth’s climate, through the injection of gaseous plumes into the atmosphere that can induce warming or cooling of the planet surface. While some of these impacts are well-known and studied, there are many older volcanic events whose details are unknown or uncertain, due to the lack of direct historical evidence.
Volcanic plumes transport volatile elements (e.g., S, Fe, Zn, Cu, Hg) that can be absorbed by trees and recorded in the yearly tree-ring layers. So far, dendrochemistry has been widely applied to assess anthropogenic pollution, but our research explores its potential as a novel proxy: by identifying chemical spikes of these elements in tree rings of known age, it may be possible to correlate them with known volcanic eruptions or identify previously unrecognized volcanic events. Here we present data obtained at Diamond synchrotron on tree rings from juniper (Juniperus communis) samples from Kevo, Finland, whose dendrochronological records extend back to the early Middle Ages. These measurements revealed distinct peaks in metal elements such as Zn and Cu, which are typically enriched in volcanic plumes and can be hosted in the wood as semi-nutrients. Some concentration peaks detected in the tree rings correspond to the ages of major Icelandic eruption from the lower Middle Ages.
These preliminary results suggest that dendrochemical analyses may provide a new archive of past volcanic activity. If validated, this approach could significantly improve reconstructions of volcanic eruptions of the past and corresponding climate variability over the last two millennia.
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Mar 2026
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I14-Hard X-ray Nanoprobe
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Diamond Proposal Number(s):
[36126]
Open Access
Abstract: Coal fly ash (CFA), a metal-rich byproduct of coal combustion is produced in vast quantities and poses significant ecological risks. CFA also contains abundant technologically relevant metal oxides and trace metals, including rare earth elements (REE), often at higher concentrations than in primary ores. This makes sustainable recovery strategies a major industrial opportunity. Here, green solvent systems were applied to leach metals from CFA, and the resulting leachates were added to cultures of Magnetospirillum gryphiswaldense (MSR1), a model magnetotactic bacterium that biomineralizes iron into membrane-bound magnetic nanoparticles (magnetosomes) and is capable of interacting with non-iron metals through adsorption and biomineralization. Eleven green solvents, including deep eutectic solvents (DES), were tested for extraction efficiency, with six showing performance comparable to a mineral acid control. Copper (Cu) emerged as the primary toxicant to MSR1, prompting selective precipitation with potassium ferrocyanide trihydrate (PFCT) to reduce its concentration. Cu-depleted lactic acid-based leachates supported MSR1 growth and magnetosome formation even without supplemented iron. Nano-XRF and ICP-MS analysis revealed MSR1 interacts with CFA-derived metals, most significantly showing that produced CFA magnetosomes contained a 5.3–6.1-fold increase in Cu compared to controls. As Cu is both a growth inhibitor and a target pollutant, these findings suggest MSR1 may bioaccumulate Cu within magnetosomes as a detoxification strategy. Overall, this study demonstrates a combined chemical–biological route for CFA valorisation, enabling recovery of diverse metals from waste while producing magnetosomes with distinct compositions.
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Mar 2026
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