Faraday Discussions最新文献

{"title":"Exploiting nanoprobe X-ray techniques for imaging of biomineralisation; chemical, structural and <i>in situ</i> opportunities.","authors":"Jessica M Walker, Miguel A Gomez-Gonzalez, Johannes Ihli, Julia E Parker","doi":"10.1039/d5fd00037h","DOIUrl":"https://doi.org/10.1039/d5fd00037h","url":null,"abstract":"<p><p>Advances in X-ray nanoprobe beamlines at synchrotrons across the world present exciting opportunities for rich multimodal imaging of biomineral structures and their formation processes. The combination of techniques provides a sensitive probe of both chemistry and structure, making X-ray nanoprobes an important tool for investigating crystallite growth and orientations, interfaces, and assembly of building blocks into hierarchical structures. A discussion of these capabilities is presented with reference to recent examples using a range of nanoprobe imaging techniques for investigating enamel structure, as well as coccolith properties. Key opportunities for the use of X-ray nanoprobes lie in exploiting the penetrating power and coherence properties of synchrotron X-rays in order to image <i>in situ</i> processes or apply coherent diffractive imaging techniques to obtain higher resolutions. To this end initial results demonstrating the observation of calcium phosphate mineralisation, in a liquid environment, using nano-X-ray fluorescence mapping are presented, and the role of X-ray dose and beam induced effects is considered. Finally novel results from tomographic ptychography imaging of <i>Mytilus edulis</i> mussel shell calcite prisms are discussed, where the segmentation of the phase density into organic and mineral content gives insights into the mechanisms underlying mineral prism formation and the role of the organic matrix in biomineralisation.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144223763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New insights into non-contact reflectance IR mapping of teeth.","authors":"Franco Lizzi, Hamza Elfarraj, Oleksandra Marushchenko, Ole Lenz, Peter Lasch, Ljiljana Puskar, Ioanna Mantouvalou, Paul Zaslansky","doi":"10.1039/d5fd00026b","DOIUrl":"https://doi.org/10.1039/d5fd00026b","url":null,"abstract":"<p><p>Teeth are made of highly mineralized tissues that withstand years of daily usage. Their mechanical properties have been studied at all length scales with ageing, but mainly small areas have been the focus of high-sensitivity chemical property quantification. A comprehensive, spatially resolved examination across centimeter sized tooth specimens is needed to expand our comprehension of young <i>versus</i> aged teeth. Specular Reflectance Fourier Transform Infrared Spectroscopy (srFTIR) is a nondestructive microscopy technique that can be used to characterize the chemical composition of mineralized surfaces. This technique provides spatially resolved chemical absorption information, making it useful to study both organics and mineral in visibly accessible tooth tissues. Highly polished dehydrated cross-sectional surfaces of bovine and human teeth were srFTIR imaged, and spectra were processed using a Kramers-Kronig transformation to generate absorbance-like chemical maps. Results are comparable with the well-established FTIR Transmission and Attenuated Total Reflection (ATR) methods. Maps of multiple <i>ν</i>₃-phosphate vibrations, <i>ν</i>₂-carbonate, and amide I reveal insights into structural and chemical variations across dentine. Young bovine teeth exhibited many chemical and structural similarities to old, partially sclerotic human teeth, affirming their use as proxies in dental research. This work highlights the capability of specular reflection infrared spectroscopy imaging to reveal spatial chemical information and expand our understanding of tooth microstructure and composition variations.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144223764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oyster larval biomineralisation - insights from electron backscatter diffraction.","authors":"Kanmani Chandra Rajan, Vengatesen Thiyagarajan, Mohamed Madhar Fazil Sheik Oli, Muthusamy Ayyadurai, Mason N Dean","doi":"10.1039/d5fd00038f","DOIUrl":"https://doi.org/10.1039/d5fd00038f","url":null,"abstract":"<p><p>The initiation of biomineralisation is crucial to the ecology of shelled organisms, for instance providing protection during early life stages when animals are particularly vulnerable. In oysters, the processes involved in early shell deposition remain debated-whether amorphous calcium carbonate (ACC) is deposited initially and transforms into aragonite, or aragonite is directly deposited-largely due to challenges examining the youngest age classes and the limited diversity of model species. Early larval shell deposition has primarily been studied in pearl oysters (<i>Pinctada</i> spp.) due to commercial interests in pearl formation. Edible oyster biomineralisation, however, remains relatively unexplored, despite the commercial importance of post-settlement survival. In this study, we provide a comparative analysis of shell crystallography of a relatively unexamined, ecologically and commercially important edible species, the Hong Kong oyster (<i>Magallana hongkongensis</i>). We focus on three important life stages-D-larvae (3 days post fertilisation), pediveliger (14 days post fertilisation) and spat (three months post settlement)-over which the shell increases drastically in thickness and alters its microstructure. Employing Scanning Electron Microscopy-based Electron BackScatter Diffraction (SEM-EBSD), we show: (1) larval shells are made entirely of aragonite crystals with no traces of ACC detected, whereas spat exhibit calcitic shells; (2) relative to spats, larval shells show a stronger alignment of their crystal <i>c</i>-axes perpendicular to the shell surface, suggesting perhaps a tighter control of mineralisation processes in early life stages; (3) shell grain area increases as the oyster matures, likely linked to the aragonite-to-calcite shift, but also maturation of the larval shell. These quantitative data on ultra- and microstructural changes in oyster shell architecture advance our understanding of early biomineralisation in edible oysters; by elucidating the mechanisms of crystal deposition and organization, we provide a foundation for designing novel materials inspired by natural biomineralisation processes.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144207159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spiers Memorial Lecture: Recent advances (and challenges) in supramolecular gels.","authors":"Haozhe Zheng, Darrin J Pochan","doi":"10.1039/d5fd00044k","DOIUrl":"10.1039/d5fd00044k","url":null,"abstract":"<p><p>Supramolecular hydrogels are physical hydrogels that are formed by non-covalent interactions such as hydrogen bonding, electrostatic attraction, hydrophobic interactions, and π-π stacking. Compared to typical, chemically cross-linked hydrogels, supramolecular networks commonly have stimuli-responsive behavior including reversibility and injectability, which are being widely studied for uses in drug delivery, tissue engineering, and wound healing. This review highlights recent developments in supramolecular network design and behavior focusing on the different possible molecular building blocks, including peptides, polysaccharides, synthetic polymers, and multicomponent systems. We further discuss self-assembly mechanisms of hydrogel formation, as well as recent advances in stimuli-responsive supramolecular hydrogels triggered by pH, temperature, and light. Advanced characterization techniques such as rheological analysis, spectroscopy, scattering methods, and electron microscopy are summarized to understand hydrogel structure, assembly pathways, and ultimate network properties. This review provides readers with an updated understanding of supramolecular hydrogels and highlights current research presented during the <i>Faraday Discussions</i> meeting on advances in supramolecular gels, promoting the rational design and development of novel materials to address complex biomedical and other technological challenges.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12131310/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144207160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seeing the invisible: XRF reveals lead distributions in coral organisms grown in the Red Sea (Gulf of Aqaba).","authors":"Katrein Sauer, Maayan Neder, Ivo Zizak, Paul Zaslansky, Tali Mass","doi":"10.1039/d5fd00024f","DOIUrl":"https://doi.org/10.1039/d5fd00024f","url":null,"abstract":"<p><p>Lead (Pb) contamination in marine ecosystems poses a significant ecological threat. Not much is known about its effects on coral reefs, which serve as vital biodiversity hotspots and climate refuges. This study revealed bioaccumulation of Pb in the organism of two stony coral species, <i>Stylophora pistillata</i> and <i>Pocillopora verrucosa</i>, widely studied in the Gulf of Aqaba. Microfocus X-ray fluorescence (XRF) imaging revealed widespread accumulation of Pb within the coral tissues but not in the skeletons. The finding that Pb predominantly accumulates in the soft tissues with no evidence of Pb in the mineral suggests that exposure was short or of low concentration. Both highlight the great sensitivity of coral organisms to Pb uptake, with likely negative impacts on the organism. We suggest that anthropogenic Pb contamination, intensified by factors such as urban runoff or industrial discharges, still poses a serious risk to coral health and resilience despite years of efforts to curb exposure. Future research should focus on the kinetics of Pb bioaccumulation, effects of short-term <i>versus</i> long-term exposure and the combined effects of heavy metals and temperature on coral physiology.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144197810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanobeam-scanning X-ray fluorescence microscopy reveals the elemental composition of dense intracellular bodies in biomineralizing coccolithophores.","authors":"Daniel M Chevrier, Shristy Gautam, André Scheffel","doi":"10.1039/d5fd00021a","DOIUrl":"https://doi.org/10.1039/d5fd00021a","url":null,"abstract":"<p><p>Coccolithophore microalgae intracellularly produce nanostructured calcitic platelets, known as coccoliths, through a biologically-controlled mineralization process. Mature coccoliths are secreted to the cell surface and assembled into a shell that envelops the cell. The large-scale global production of coccoliths, followed by their sedimentation to the ocean floor, significantly contributes to carbon cycling. Despite progress in understanding the biomineralization pathway of coccoliths, we are still limited in our ability to predict how future climate conditions will impact coccolith formation and thus ocean carbon fluxes. Investigating coccolith biomineralization at the single-cell level is therefore critical to advance our understanding but remains challenging since current imaging techniques lack the combined spatial and temporal resolution coupled with element-specific detection to follow processes <i>in situ</i>. In light of this gap, nanobeam-scanning X-ray fluorescence microscopy (nano-XRF) in the hard X-ray regime is employed here to investigate the intracellular elemental distribution of the coccolithophore <i>Gephyrocapsa huxleyi</i> (formerly <i>Emiliania huxleyi</i>) achieving a resolution of 100 nm and elemental detection from phosphorus (P) to zinc (Zn). Calcium- and phosphorus-rich intracellular bodies, previously proposed to be involved in coccolith biomineralization, were observed in cells initially prepared <i>ex situ</i> by drying. Interestingly, nano-XRF imaging reveals metal species (<i>e.g.</i>, Mn, Fe, Zn) within these bodies that were not detected in earlier studies, suggesting multiple biological roles for these structures. Moving towards native-state imaging, <i>G. huxleyi</i> was then imaged in the hydrated state using a dedicated liquid cell device. Measurements were performed on <i>G. huxleyi</i> cells both with and without coccolith shell in sea water medium and compared to those of dried cells, demonstrating comparable image quality. The future potential and limitations of liquid cell nano-XRF imaging for coccolithophores and other microorganisms are further discussed.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144197809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D Calcium carbonate polymorphs imaging with stimulated Raman scattering in biominerals.","authors":"Hamadou Dicko, Jéremie Vidal-Dupiol, Denis Saulnier, Eric Tambutté, Alexander Venn, Sylvie Tambutté, Virginie Chamard, Julien Duboisset","doi":"10.1039/d5fd00025d","DOIUrl":"https://doi.org/10.1039/d5fd00025d","url":null,"abstract":"<p><p>We present a highly sensitive coherent Raman microscopy approach, which allows for the tridimensional (3D) imaging of a series of carbonate polymorphs in marine organisms. CaCO₃ biomineralization occurs from the transformation of metastable amorphous precursors and other crystalline phases into a final crystalline phase. Understanding biomineralization pathways requires identifying this physico-chemical temporal sequence. Our approach exploits the different vibrational signatures of amorphous calcium carbonate, aragonite, calcite, Mg-calcite or hemi-hydrated calcium carbonate. This optical method enables the production of spatially and spectrally resolved images of the different compounds. When applied on the growing edge of post-mortem samples of both <i>Pinctada margaritifera</i> pearl oyster shell and <i>Stylophora pistillata</i> coral, it allows for inferring a temporal crystallisation sequence. We thus highlight the existence of intermediate crystalline phases, involving magnesian calcite or hemi-hydrated calcium carbonate, respectively.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144186082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined crystallographic study of king scallop (<i>Pecten maximus</i>) shells using SEM, EBSD and Raman spectroscopy.","authors":"Lise Guichaoua, Natalie Reznikov, Bryce D Stewart, Roland Kröger, Raynald Gauvin","doi":"10.1039/d5fd00029g","DOIUrl":"https://doi.org/10.1039/d5fd00029g","url":null,"abstract":"<p><p>The shells of <i>Pecten maximus</i> (king scallop) are composed primarily of polycrystalline calcitic calcium carbonate, with a crucial aragonitic prismatic myostracum layer that facilitates soft tissue attachment and contributes to mechanical strength. Despite its importance, the impact of environmental stressors, such as metal contamination, on the myostracum remains underexplored. Hence, this study's main goal was to shed light on the microstructure and crystallography of king scallop shells, particularly the myostracum region, using a combination of scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) analysis, and Raman spectroscopy. This approach was chosen to develop new protocols that integrate imaging techniques for a systematic analysis of pollution effects on shell growth and properties. Such an understanding is crucial for assessing the impact of environmental contamination on shell structure and composition. We compared samples from a metal contaminated site (Laxey) with those from non-contaminated site (Bradda) around the Isle of Man, to determine which structural and crystallographic information is detectable using the selected microscopy and spectroscopy techniques. SEM imaging showed a similar myostracum organization in specimens from both sites, with elongated, oriented grains. However, the non-contaminated site shell had more regular and elongated grains, while the shell from the contaminated site exhibited a broader grain size distribution, visible <i>via</i> electron channeling contrast and backscattered electron detection. EBSD analysis confirmed that both types exhibited well-crystallized aragonite in the myostracum, with slight differences in grain orientation and grain size with co-orientation indicating a marginal reduction in crystallographic alignment in the contaminated site shell. Raman maps reveal shifts in peak positions, indicating crystallite strain and differences in grain size. These variations may be related to a biological adaptation aimed at toughening the shell, but pollution could disrupt this crystallization process, weakening the shell. The combination of these techniques can advance our understanding of the microstructural alterations caused by metal contamination, highlighting its potential impact on the structural integrity of the shell. This study is a proof of principle study showing how a combination of different established imaging techniques can provide complementary and novel insights into the structure and composition of the king scallop myostracum. This systematic approach aims to develop new evaluation approaches for the study of the effects of environmental pollutants on the crystallography and microstructure of marine bivalve shells and hence their resilience.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144179562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomistic insight into the interaction of aspartic acid species with calcium carbonate: model development.","authors":"Raffaella Demichelis, Blake I Armstrong, Paolo Raiteri, Julian D Gale","doi":"10.1039/d5fd00008d","DOIUrl":"https://doi.org/10.1039/d5fd00008d","url":null,"abstract":"<p><p>The development of models that allow access to atomic-scale information is crucial for expanding our understanding of interfacial processes that enable the formation and growth of biominerals in both abiotic and biogeochemical environments. In this work, a recently developed potential model for the simulation of aspartic acid species in biomineralization environments has been combined with the most recent calcium carbonate potential model. Force field parameters have been refined and validated, demonstrating high accuracy in predicting ion pair formation dynamics and free energy. Two different options to model the interaction between aspartic acid species and carbonate anions have been discussed, and preliminary simulations of aspartic acid on calcium carbonate mineral surfaces have been performed. The steps to predict accurate binding free energies of molecules on mineral surfaces have been discussed using acetate and the {020} surface of monoclinic vaterite as a model system.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144179783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure <i>versus</i> composition: a comparative study across scales.","authors":"Yannicke Dauphin, Cedrik Lo, Gergely Németh, Christophe Sandt, Jean-Pierre Cuif","doi":"10.1039/d5fd00012b","DOIUrl":"10.1039/d5fd00012b","url":null,"abstract":"<p><p>Mollusk shells are composed of biominerals. While their mineral polymorphs are limited, their organic components number in the hundreds, if not thousands. Identifying these individual components is only the first step; understanding how they interact to form a shell remains an ongoing challenge. Infrared (IR) spectroscopy is a powerful technique for analyzing the structure and composition of these components while preserving their topographic relationships. This study employed three scales of observation and three samples: <i>Concholepas</i>, <i>Pinctada</i>, and cultivated pearls. Previously available data on their microstructure and compositions were utilized to explore potential correlations with results obtained from various techniques. IR analysis, being non-destructive, facilitates subsequent comparisons with other analytical methods such as Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and X-ray Absorption Near Edge Structure (XANES), thanks to the precise localization of IR data. The findings reveal that data from earlier non-IR analyses align with results from new IR techniques, including Diffuse Reflectance Infrared Fourier Transform (DRIFT), Optical Photothermal Infrared Spectroscopy (O-PTIR), and Scattering-Type Scanning Near-Field Optical Microscopy (sSNOM). This concordance validates the application of these new IR methods for studying biogenic calcium carbonate. Furthermore, the high spatial resolution of O-PTIR and sSNOM enables detailed visualization of structural and compositional features. For instance, the techniques reveal the intricate inner structure of three-month-old pearls, the distribution of proteins, lipids, and sulphated sugars in <i>Concholepas</i>, and the nanoscale differences in the arrangement of nacre and prisms in <i>Pinctada</i>.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144179545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}