I05-ARPES
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Cedric
Schmitt
,
Lukas
Gehrig
,
Kilian
Strauß
,
Jonas
Erhardt
,
Merit
Spring
,
Bing
Liu
,
Matthew D.
Watson
,
Han
Gao
,
Hanbo
Xiao
,
Zhongkai
Liu
,
Gang
Li
,
Giorgio
Sangiovanni
,
Jörg
Schäfer
,
Ralph
Claessen
,
Simon
Moser
Diamond Proposal Number(s):
[41909]
Abstract: Circular dichroism in angle-resolved photoemission spectroscopy (CD-ARPES) is widely used to probe orbital angular momentum (OAM) and Berry-curvature-related phenomena in two-dimensional quantum materials. However, in many materials, conventional micron-scale measurements often average over domains with opposite OAM polarization, canceling intrinsic dichroic signals and leaving spectra dominated by extrinsic asymmetries arising from photoelectron final-state interference. Here, we combine circularly polarized light with NanoARPES to achieve spatially resolved CD-ARPES with sub-800 nm resolution. By isolating individual domains, this approach enables direct access to the intrinsic OAM texture. As a model system, we investigate the K/K′ point valley states of the quantum spin Hall insulator indenene─a triangular indium monolayer epitaxially grown on SiC(0001)─where substrate-induced terraces host alternating valley configurations whose dichroic response is averaged out in conventional measurements. Terrace-resolved NanoARPES disentangles these contributions, allowing direct visualization of oppositely polarized domains and revealing the OAM texture associated with a topological band inversion. Our results establish spatially resolved CD-ARPES as a robust approach for isolating intrinsic OAM contrast by eliminating domain averaging and correcting for extrinsic geometry-dependent contributions. This enables direct access to the Berry curvature near the Fermi level, providing a powerful probe of the system’s intrinsic topological character.
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Oct 2026
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B21-High Throughput SAXS
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Lucrezia
Caselli
,
Marta
Rojas-Rodríguez
,
Valentina
Pacciani
,
Martino
Calamai
,
Roberto
Frigerio
,
Andrea
Zendrini
,
Gennaro
Sanità
,
Emanuela
Esposito
,
Anna
Leung
,
Hanna
Wacklin-Knecht
,
Ben
Humphreys
,
Paolo
Arosio
,
Jacopo
Cardellini
,
Debora
Berti
Diamond Proposal Number(s):
[43918]
Open Access
Abstract: Lipid nanoparticles (LNPs) are central to nanomedicine, yet their clinical translation is limited by the difficulty of predicting structure-bioactivity relationships. Although the biomolecular corona is known to define the nanoparticle biological identity by modifying surface properties, its effect on internal nanoparticle organization remains largely unexplored. Since the internal lipid organization of LNPs governs key properties, including stability, cargo protection, internalization and intracellular trafficking, understanding this coupling is critical to correlate synthetic design to therapeutic outcome. Here, combining structural and mechanistic evidence, we show that plasma lipoproteins engage in molecular-scale lipid exchange with the LCNP membrane, rather than persisting as an adsorbed layer of intact particles, actively remodeling the internal nanoparticle structure. Using model lipid liquid-crystalline nanoparticles with well-defined cubic and inverse hexagonal phases, we systematically investigate how lipoproteins modulate LNP structure. Combining fluorescence nanoparticle tracking, synchrotron small-angle X-ray scattering, cryo-electron microscopy, and neutron reflectometry with isotopic contrast matching, we provide evidence of lipoprotein-driven lipid transfer and phase reorganization at the nanoscale. We observe a phase-selective response: inverse hexagonal LNPs remain structurally stable despite lipid exchange, whereas cubic LNPs undergo pronounced remodeling, including significant change in size and lattice ordering. These transformations correlate with distinct cellular uptake profiles. Our findings suggest that in soft lipid nanoparticles, the biological identity commonly described as a biomolecular corona is not merely a surface event but an interface-mediated process that reshapes the nanoparticle internal structure, with direct implications for next-generation nanomedicine design.
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Sep 2026
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I03-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Abstract: The nanofabrication of functional protein-based surfaces is challenging due to the chemical complexity of proteins and their unpredictable behavior at the solid–liquid interface. Many proteins of interest–such as antibodies or large enzymatic complexes–lack strong and dynamic protein–protein and protein–surface interactions necessary to drive self-assembly of stable arrays with high surface coverage. Additionally, adsorption-induced conformational changes at the solid–liquid interface could lead to a loss of activity and increase the risk of undesirable interfacial processes. Here we introduce SAKe, a Kelch-like designer protein, as a versatile platform to address these challenges. Ancestral sequence reconstruction led to high thermal stability, and the high symmetry allowed modularity of the protein’s core. Rational engineering of the bottom side allowed SAKe to form large (up to 5 μm in length), well-defined and pH-dependent two-dimensional assemblies while maintaining structural integrity, which is key for further development of functional materials. SAKe self-assembly was investigated through in-liquid atomic force microscopy on muscovite mica. High resolution imaging confirmed the integrity of the SAKe protein upon adsorption on the solid–liquid interface. These results showcase the SAKe protein as a platform for the further engineering of functional protein-based two-dimensional materials.
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Aug 2026
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Open Access
Abstract: Metal–organic frameworks (MOFs) are often assessed for stability using end-point structural metrics, yet their exposure-relevant chemical identity at the metal center may evolve on much shorter time scales in realistic aqueous environments. Here we examine nanoscale copper–imidazolate (CuIm) MOFs transformation across three benchmark matrices representing an abiotic-to-biorelevant gradient: a freshwater-like groundwater matrix (borehole water), a marine-like high-salinity matrix (artificial seawater), and a ligand-rich, protein-free cell-culture medium (serum-free DMEM) used here as a chemically complex challenge matrix. Using ex situ time-resolved separation of particle-associated and dissolved/complexed fractions coupled with copper-centered speciation analysis, we resolve a distinct kinetic hierarchy. CuIm remains largely conserved in borehole water, exhibits gradual reorganization in artificial seawater, and undergoes rapid transformation in serum-free DMEM, with the particle-associated fraction converging to an apparent end-state spectrum by ∼4 h. Medium-dependent copper mobilization to the dissolved/complexed pool accompanies these speciation trajectories. End-point characterization further indicates that framework-like structural signatures can persist while surface chemistry is substantially altered, demonstrating a decoupling between long-range order and node/surface identity. Collectively, these findings show that CuIm follows matrix-selected transformation trajectories with pronounced early-time trajectory shifts and that stability assessments must be grounded in time-resolved chemical identity rather than end-point crystallinity alone.
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Jun 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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I12-JEEP: Joint Engineering, Environmental and Processing
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Abstract: Amid rising global demand for renewable energy and effective plastic waste management, adopting green methods to utilize plastic waste for chemicals is a win–win strategy. Constituting the largest amount of single-use plastic litter worldwide, cellulose diacetate (CDA) based waste cigarette filters urgently require sustainable valorization pathways. However, CDA photoconversion remains highly challenging due to substantial energy barriers for selective bond cleavage, inadequate radical generation capability, and inefficient charge-carrier separation. Herein we propose a strategy to efficiently obtain C2H4 through carbene-mediated CDA photoconversion by using a sulfur vacancy-regulated copper-gallium-zinc-sulfide (VS-CGZS) catalyst. VS-CGZS enhances the thermal effect of light and lowers the energy barrier for acetyl group (*CH3CO) desorption from CDA. VS reduces the adsorption energy of *CH3CO on VS-CGZS and facilitated :CH2 formation. Consumption of photogenerated holes via *CH3CO desorption and VS-enhanced carrier separation synergistically elevate the photogenerated electrons concentration for :CH2 coupling, thereby selectively triggering and boosting C2H4 yield. Therefore, we achieve a record-breaking 14.43 mmol·gcat–1 C2H4 for CDA photoconversion within 4 h, over 6 times exceeding previous reports on photoconverting plastic into C2H4. This work establishes a strategy for efficient ethylene production from photoconversion of cellulose diacetate and carves out a paradigm in solar-driven plastic valorization.
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May 2026
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I07-Surface & interface diffraction
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Diamond Proposal Number(s):
[35227]
Open Access
Abstract: Organic semiconductors offer a long-spin coherence time and diffusion length due to the weak spin–orbit and hyperfine interactions in these materials. However, in commonly used lateral field-effect transistor structures, it is challenging to define device dimensions comparable to the spin diffusion length. On the other hand, vertical structures, offering smaller device dimensions, are facing issues due to the low carrier mobilities in the vertical dimension. Here, we investigate spin relaxation in rubrene thin films with a triclinic phase, which are doped with C60F48 by coevaporation. The doping provides an efficient way to generate charge carriers, and their high out-of-plane mobility should enhance long-spin diffusion. Using electron-spin resonance, we show that the spin relaxation is governed by the interaction with the dopant counterions and estimate the spin diffusion length to be ∼200 nm. This is comparable to the film thickness, which should make such doped rubrene films an attractive system for spintronic device applications.
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Mar 2026
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I04-1-Macromolecular Crystallography (fixed wavelength)
I04-Macromolecular Crystallography
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André
Shamsabadi
,
Adam
Creamer
,
Christy J.
Sadler
,
Aida
Abdelwahed
,
Katherine U.
Gaynor
,
Yuliya
Demydchuk
,
Gabriela
Ivanova-Berndt
,
Katerine
Van Rietschoten
,
Paul
Beswick
,
Liuhong
Chen
,
Gustavo
Arruda Bezerra
,
Aleksei
Lulla
,
Paul
Brear
,
Marko
Hyvonen
,
Michael J.
Skynner
,
Molly M.
Stevens
Diamond Proposal Number(s):
[25402]
Open Access
Abstract: Constrained bicyclic peptides (Bicycle molecules) with high affinity for biological targets have emerged as potentially powerful therapeutic agents, particularly for the in vivo targeting of cancer receptors. However, their antibody-mimetic properties have yet to be explored for use in diagnostic immunoassays. These synthetically derived compounds serve as biorecognition scaffolds that allow for facile site-selective modification and large-scale production. A phage display screen against various constructs of the SARS-CoV-2 nucleocapsid (N) protein identified several Bicycle molecules with binding affinities ranging from the micromolar to the low nanomolar range. These Bicycle molecules were validated in the development of enzyme- and nanozyme-linked immunosorbent assays, as well as enzymatic and colorimetric nanoparticle-based lateral flow immunoassays (LFIA) for the detection of ultralow concentrations of the SARS-CoV-2 N protein. We envision that these moieties enable robust, cost-effective, and large-scale development of ultrasensitive biosensors for a diverse range of biomarkers by leveraging their high binding affinity, minimalistic scaffold, and synthetic accessibility.
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Feb 2026
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Sanghyo
Lee
,
Sojin
Kim
,
Jinseok
Ryu
,
Jaewook
Lee
,
Jinseok
Hong
,
Ji Eun
Kim
,
Ju-Young
Cha
,
Yunho
Shin
,
Daewoong
Kwon
,
Jung Ho
Yoon
,
Min Hyuk
Park
,
Miyoung
Kim
,
Seung-Yong
Lee
Abstract: Understanding electric-field-induced phase transitions is crucial for optimizing the ferroelectric and antiferroelectric properties of hafnium zirconium oxide (Hf0.5Zr0.5O2, HZO) thin films. Here, we use in situ transmission electron microscopy (TEM) to uncover the nanoscale mechanism of field-induced phase evolution in ultrathin HZO films at the morphotropic phase boundary (MPB), directly visualizing oxygen vacancy migration and its correlation with the transformation from the nonpolar tetragonal to polar orthorhombic phase. Our in situ TEM setup applied sub-100 μs bipolar voltage pulses, mimicking real device operation while allowing the detection of the subtle changes induced by such short pulses. Unsupervised machine learning analysis of electron energy-loss spectroscopy spectrum images (EELS-SIs) revealed distinct spectral features associated with local structural evolution, with quantitative results confirming oxygen-deficient regions aligned with orthorhombic phase formation. Unlike conventional TEM studies confined to a few nanoscale domains, this approach enables film-scale interpretation of phase evolution, capturing broader trends beyond isolated observations. Concurrent oxygen content changes in the TiN electrode further indicate active vacancy exchange between HZO and TiN under bias. These findings directly link oxygen vacancy dynamics to polarization switching, offering critical guidance for stabilizing ferroelectric phases and advancing next-generation memory and logic devices.
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Feb 2026
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I05-ARPES
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Oliver J.
Clark
,
Anugrah
Azhar
,
Thi-Hai-Yen
Vu
,
Benjamin A.
Chambers
,
Federico
Mazzola
,
Sadhana
Sridhar
,
Geetha
Balakrishnan
,
Aaron
Bostwick
,
Chris
Jozwiak
,
Eli
Rotenberg
,
Sarah L.
Harmer
,
Mohammad Saeed
Bahramy
,
Michael S.
Fuhrer
,
Mark T.
Edmonds
Diamond Proposal Number(s):
[40610]
Open Access
Abstract: Discovering and engineering spin-polarized surface states in the electronic structures of condensed matter systems is a crucial first step in the development of spintronic devices, wherein spin-polarized bands crossing the Fermi level can facilitate information transfer. Here, through nanofocused angle-resolved photoemission spectroscopy (nano-ARPES) and density functional theory-based calculations, we show that the interface between monolayer WSe2 and metallic NbSe2 exhibits a negative Schottky barrier height of ∼ −30 meV: the K-point valleys of the semiconducting layer are shifted by ∼800 meV to produce a surface-localized Fermi surface populated only by spin-polarized charge carriers. By increasing the WSe2 thickness, the Fermi pockets can be moved from K to Γ, demonstrating tunability of novel semimetallic phases that exist atop a substrate additionally possessing charge density wave and superconducting phases. Together, this study provides a spectroscopic understanding into p-type, Schottky barrier-free interfaces, which are of urgent interest for bypassing the limitations of current-generation vertical field effect transistors, in addition to longer-term spintronics development.
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Feb 2026
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