TY - JOUR A1 - Redda, Zinnabu T. A1 - Brennecke, Daniel A1 - Prinz, Carsten A1 - Yimam, Abubeker A1 - Barz, Mirko A1 - Kadow, Steffen A1 - Laß-Seyoum, Asnakech T1 - Synthesis and characterization of AlPO4-18 supported mesoporous and crystalline β-Mo2C, Ni3C, and WC nanoparticles N2 - Developing high-efficiency, high-stability, and low-cost deoxygenation and hydrocracking catalysts could be considered one of the most significant breakthroughs in catalytic hydroprocessing. The present study utilized aluminophosphate (AlPO4-18), a zeolite-like molecular sieve, as catalyst support for producing carbon-coated β-Mo2C, Ni3C, and WC nanoparticles. The synthesis used an incipient wetness impregnation followed by a temperature-programmed reduction-carburization approach which involved cracking a hydrocarbon gas, propane, in a hydrogen environment. The synthesis parameters were a 1:7 propane/hydrogen reductive-carburizing gas stream, 15 wt.% metal loading, an 800 °C carburization temperature ramped-up at a heating rate of 10 °C min−1, a 2-h holding time, and a 1-h holding time in hydrogen. The synthesized catalysts were characterized using thermogravimetry mass spectroscopy/temperature-programmed oxidation (TPO TG-MS), nitrogen physisorption at 77 K, X-ray diffraction (XRD), and transmission electron microscopy/energy-dispersive X-ray spectroscopy (TEM EDS). TPO TG-MS, nitrogen physisorption, TEM, and XRD characterization results proved that atomic carbon was successfully incorporated into the lattice interstitials, resulting in thermally stable, well-dispersed, crystalline and mesoporous β-Mo2C/AlPO4-18, Ni3C/AlPO4-18, and WC/AlPO4-18 nanoparticles. XRD analysis showed structural evolution during reduction-carburization, with average crystallite sizes of metal-containing particles of 8.2–9.22, 6.64–8.50, and 6.03–7.56 nm for β-Mo2C/AlPO4-18, Ni3C/AlPO4-18, and WC/AlPO4-18, respectively. These values did not significantly deviate from high-resolution TEM analysis. The surface areas of the nanoparticles were categorized in decreasing order as WC/AlPO4-18 > Ni3C/AlPO4-18 > β-Mo2C/AlPO4-18, with values of 193.79, 169.05, and 66.57 m2 g−1, respectively. In conclusion, these carbon-coated metal carbide nanoparticles with excellent thermal, structural, microscopic, and textural properties can be viable alternatives to noble metal catalysts for producing bio-jet fuel using the hydroprocessing pathway. KW - Catalyst synthesis KW - Temperature-programmed reduction-carburization KW - Catalyst characterization KW - BET surface area KW - Nanoparticle KW - Transition metal carbide catalyst KW - TEM PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608182 DO - https://doi.org/10.1007/s10562-024-04791-y SN - 1011-372X SN - 1572-879X VL - 154 SP - 5969 EP - 5988 PB - Springer Science and Business Media CY - Dordrecht AN - OPUS4-60818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neamtu, Mariana A1 - Nadejde, C. A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf A1 - Verestiuc, L. A1 - Panne, Ulrich T1 - Functionalized magnetic nanoparticles: Synthesis, characterization, catalytic application and assessment of toxicity N2 - Cost-effective water cleaning approaches using improved Treatment technologies, for instance based on catalytic processes with high activity catalysts, are urgently needed. The aim of our study was to synthesize efficient Fenton-like photo-catalysts for rapid degradation of persistent organic micropollutants in aqueous medium. Iron-based nanomaterials were chemically synthesized through simple procedures by immobilization of either iron(II) oxalate (FeO) or iron(III) citrate (FeC) on magnetite (M) nanoparticles stabilized with polyethylene glycol (PEG). Various investigation techniques were performed in order to characterize the freshly prepared catalysts. By applying advanced oxidation processes, the effect of catalyst dosage, hydrogen peroxide concentration and UV-A light exposure were examined for Bisphenol A (BPA) conversion, at laboratory scale, in mild conditions. The obtained results revealed that BPA degradation was rapidly enhanced in the presence of low-concentration H2O2, as well as under UV-A light, and is highly dependent on the surface characteristics of the catalyst. Complete photo-degradation of BPA was achieved over the M/PEG/FeO catalyst in less than 15 minutes. Based on the catalytic performance, a hierarchy of the tested catalysts was established: M/PEG/FeO > M/PEG/FeC > M/PEG. The results of cytotoxicity assay using MCF-7 cells indicated that the aqueous samples after treatment are less cytotoxic. KW - Bisphenol A KW - Magnetic nanocatalyst KW - Endocrine disruptor KW - Nanoparticle KW - Photodegradation KW - Fenton PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-448297 DO - https://doi.org/10.1038/s41598-018-24721-4 SN - 2045-2322 VL - 8 SP - Article 6278, 1 EP - 11 PB - Springer Nature CY - London AN - OPUS4-44829 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Babick, F. A1 - Mielke, Johannes A1 - Wohlleben, W. A1 - Weigel, St. A1 - Hodoroaba, Vasile-Dan T1 - How reliably can a material be classified as a nanomaterial? Available particle-sizing techniques at work N2 - Currently established and projected regulatory frameworks require the classification of materials (whether nano or non-nano) as specified by respective definitions, most of which are based on the size of the constituent particles. This brings up the question if currently available techniques for particle size determination are capable of reliably classifying materials that potentially fall under these definitions. In this study, a wide variety of characterisation techniques, including counting, fractionating, and spectroscopic techniques, has been applied to the same set of materials under harmonised conditions. The selected materials comprised well-defined Quality control materials (spherical, monodisperse) as well as industrial materials of complex shapes and considerable polydispersity. As a result, each technique could be evaluated with respect to the determination of the number-weighted median size. Recommendations on the most appropriate and efficient use of techniques for different types of material are given. KW - Nanomaterial classification KW - Nanoparticle KW - Number-weighted median size KW - Tiered KW - Particle size analysis KW - Nanometrology KW - Characterisation techniques PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-367922 UR - http://link.springer.com/article/10.1007/s11051-016-3461-7 DO - https://doi.org/10.1007/s11051-016-3461-7 SN - 1388-0764 SN - 1572-896X VL - 18 IS - 6 SP - Article 158, 1 EP - 40 PB - Springer AN - OPUS4-36792 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bresch, Harald A1 - Hodoroaba, Vasile-Dan A1 - Schmidt, Alexandra A1 - Rasmussen, K. A1 - Rauscher, H. T1 - Counting Small Particles in Electron Microscopy Images — Proposal for Rules and Their Application in Practice N2 - Electron microscopy (EM) is the gold standard for the characterisation of the morphology (size and shape) of nanoparticles. Visual observation of objects under examination is always a necessary first step in the characterisation process. Several questions arise when undertaking to identify and count particles to measure their size and shape distribution. In addition to challenges with the dispersion and identification of the particles, more than one protocol for counting particles is in use. This paper focuses on precise rules for the counting of particles in EM micrographs, as this influences the measurement accuracy of the number of particles, thus implicitly affecting the size values of the counted particles. We review and compare four different, commonly used methods for counting, which we then apply in case studies. The impact of the selected counting rule on the obtained final particle size distribution is highlighted. One main aim of this analysis is to support the application of a specific, well-defined counting approach in accordance with regulatory requirements to contribute to achieving more reliable and reproducible results. It is also useful for the new harmonised measurement procedures for determining the particle size and particle size distribution of nanomaterials. KW - Nano KW - Particle size distribution KW - Nanoparticle KW - Nanomaterial KW - OECD PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551891 DO - https://doi.org/10.3390/nano12132238 SN - 2079-4991 VL - 12 IS - 13 SP - 2238 PB - MDPI CY - Basel AN - OPUS4-55189 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Risse, Kerstin A1 - Nikiforidis, Constantinos V. A1 - Morris, Imogen A1 - Thünemann, Andreas A1 - Drusch, Stephan T1 - Regulating the heat stability of protein-phospholipid stabilised oil-water emulsions by changing the phospholipid headgroup or fatty acyl chain N2 - Stabilising oil–water emulsions remains a central challenge across food, pharmaceutical and cosmetic applications. β-lactoglobulin (β-LG) and phospholipids (PLs) can act synergistically at oil-water interfaces: PLs adsorb rapidly, while β-LG forms a viscoelastic protein network that enhances long-term stability. However, competitive adsorption between proteins and PLs can disrupt interfacial structure. In addition, for commercial production, emulsions are often exposed to heat treatment during or after manufacture, for instance due to food safety requirements. Yet, the combined effects of PL structure and heat treatment on interfacial organisation and emulsion stability remain poorly understood. Here we show that PL saturation and processing temperature jointly determine interfacial organisation, protein-PL interactions and emulsion stability. Using β-LG-PL emulsions, we combined ζ-potential measurements, small-angle X-ray scattering (SAXS), micro-differential scanning calorimetry (μDSC), X-ray diffraction and confocal laser scanning microscopy (CLSM) to link interfacial composition with functional stability. Below the β-LG denaturation temperature (≤75 °C), saturated PLs promoted partial unfolding of β-LG at the interface without displacement, producing mixed protein-PL networks with enhanced viscoelasticity and stability. Unsaturated PLs displaced β-LG, yielding less elastic interfaces and promoting protein aggregation in the bulk. At ≥75 °C, increased hydrophobicity intensified protein-protein interactions irrespective of PL type. Our findings reveal that saturated PLs shift the β-LG denaturation temperature upward by restricting molecular mobility, without preventing quaternary-level protein-protein interactions. Thermal denaturation, regardless of PL type, promoted interfacial multilayer formation at 90 °C. These results provide a mechanistic framework for tailoring emulsion stability via lipid saturation and processing temperature. KW - Small-angle X-ray scattering KW - SAXS KW - Nanostructure KW - Reference Method KW - Colloid KW - Nanoparticle PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648956 DO - https://doi.org/10.1016/j.jcis.2025.139530 SN - 0021-9797 VL - 705 SP - 1 EP - 25 PB - Elsevier Inc. AN - OPUS4-64895 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bender, P A1 - Balceris, C. A1 - Ludwig, F A1 - Posth, O A1 - Bogart, L. K. A1 - Szczerba, Wojciech A1 - Castro, A A1 - Nilsson, L A1 - Costo, R A1 - Gavilan, H A1 - Gonzalez-Alonso, D A1 - de Pedro, I A1 - Barquin, L. F. A1 - Johansson, C T1 - Distribution functions of magnetic nanoparticles determined by a numerical inversion method N2 - In the present study, we applied a regularized inversion method to extract the particle size, magnetic moment and relaxation-time distribution of magnetic nanoparticles from small-angle x-ray scattering (SAXS), DC magnetization (DCM) and AC susceptibility (ACS) measurements. For the measurements the particles were colloidally dispersed in water. At first approximation the particles could be assumed to be spherically shaped and homogeneously magnetized single-domain particles. As model functions for the inversion, we used the particle form factor of a sphere (SAXS), the Langevin function (DCM) and the Debye model (ACS). The extracted distributions exhibited features/peaks that could be distinctly attributed to the individually dispersed and non-interacting nanoparticles. Further analysis of these peaks enabled, in combination with a prior characterization of the particle ensemble by electron microscopy and dynamic light scattering, a detailed structural and magnetic characterization of the particles. Additionally, all three extracted distributions featured peaks, which indicated deviations of the scattering (SAXS), magnetization (DCM) or relaxation (ACS) behavior from the one expected for individually dispersed, homogeneously magnetized nanoparticles. These deviations could be mainly attributed to partial agglomeration (SAXS, DCM, ACS), uncorrelated surface spins (DCM) and/or intra-well relaxation processes (ACS). The main advantage of the numerical inversion method is that no ad hoc assumptions regarding the line shape of the extracted distribution functions are required, which enabled the detection of these contributions. We highlighted this by comparing the results with the results obtained by standard model fits, where the functional form of the distributions was a priori assumed to be log-normal shaped. KW - SAXS KW - Small-angle X-ray scattering KW - Nanoparticle PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-429373 DO - https://doi.org/10.1088/1367-2630/aa73b4 SN - 1367-2630 VL - 19 SP - 073012, 1 EP - 073012, 19 PB - IOP Publ. Ltd. AN - OPUS4-42937 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liebig, F. A1 - Thünemann, Andreas A1 - Koetz, J. T1 - Ostwald Ripening Growth Mechanism of Gold Nanotriangles in Vesicular Template Phases N2 - The mechanism of nanotriangle formation in multivesicular vesicles (MMV) is investigated by using time-dependent SAXS measurements in combination with UV−vis spectroscopy, light, and transmission electron microscopy. In the first time period 6.5 nm sized spherical gold nanoparticles are formed inside of the vesicles, which build up soft nanoparticle aggregates. In situ SAXS experiments show a linear increase of the volume and molar mass of nanotriangles in the second time period. The volume growth rate of the triangles is 16.1 nm3/min, and the growth rate in the vertical direction is only 0.02 nm/min. Therefore, flat nanotriangles with a thickness of 7 nm and a diameter of 23 nm are formed. This process can be described by a diffusionlimited Ostwald ripening growth mechanism. TEM micrographs visualize soft coral-like structures with thin nanoplatelets at the periphery of the aggregates, which disaggregate in the third time period into nanotriangles and spherical particles. The 16 times faster growth of nanotriangles in the lateral than that in the vertical direction is related to the adsorption of symmetry breaking components, i.e., AOT and the polyampholyte PalPhBisCarb, on the {111} facets of the gold nanoplatelets in combination with confinement effects of the vesicular template phase. KW - Gold KW - Nanoparticle KW - Small-angle x-ray scattering KW - SAXS KW - Kinetics PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-379261 DO - https://doi.org/10.1021/acs.langmuir.6b02662 SN - 0743-7463 VL - 32 IS - 42 SP - 10928 EP - 10935 PB - American Chemical Society AN - OPUS4-37926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chowdhary, S. A1 - Moschner, J. A1 - Mikolajczak, D. J. A1 - Becker, M. A1 - Thünemann, Andreas A1 - Kästner, Claudia A1 - Klemczak, D. A1 - Stegemann, A.-K. A1 - Böttcher, C. A1 - Metrangolo, P. A1 - Netz, R. R. A1 - Koksch, B. T1 - The Impact of Halogenated Phenylalanine Derivatives on NFGAIL Amyloid Formation N2 - The hexapeptide hIAPP22–27 (NFGAIL) is known as a crucial amyloid core sequence of the human islet amyloid polypeptide (hIAPP) whose aggregates can be used to better understand the wild‐type hIAPP′s toxicity to β‐cell death. In amyloid research, the role of hydrophobic and aromatic‐aromatic interactions as potential driving forces during the aggregation process is controversially discussed not only in case of NFGAIL, but also for amyloidogenic peptides in general. We have used halogenation of the aromatic residue as a strategy to modulate hydrophobic and aromatic‐aromatic interactions and prepared a library of NFGAIL variants containing fluorinated and iodinated phenylalanine analogues. We used thioflavin T staining, transmission electron microscopy (TEM) and small‐angle X‐ray scattering (SAXS) to study the impact of side‐chain halogenation on NFGAIL amyloid formation kinetics. Our data revealed a synergy between aggregation behavior and hydrophobicity of the phenylalanine residue. This study introduces systematic fluorination as a toolbox to further investigate the nature of the amyloid self‐assembly process. KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Nanostructure KW - Peptide KW - Amyloid PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518632 DO - https://doi.org/10.1002/cbic.202000373 VL - 21 IS - 24 SP - 3544 EP - 3554 PB - Wiley CY - Weinheim AN - OPUS4-51863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liebig, F. A1 - Sarhan, R. M. A1 - Schmitt, C. N. Z. A1 - Thünemann, Andreas A1 - Prietzel, C. A1 - Bargheer, M. A1 - Koetz, J. T1 - Gold Nanotriangles with Crumble Topping and their Influence on Catalysis and Surface‐Enhanced Raman Spectroscopy N2 - By adding hyaluronic acid (HA) to dioctyl sodium sulfosuccinate (AOT)‐stabilized gold nanotriangles (AuNTs) with an average thickness of 7.5±1 nm and an edge length of about 175±17 nm, the AOT bilayer is replaced by a polymeric HA‐layer leading to biocompatible nanoplatelets. The subsequent reduction process of tetrachloroauric acid in the HA‐shell surrounding the AuNTs leads to the formation of spherical gold nanoparticles on the platelet surface. With increasing tetrachloroauric acid concentration, the decoration with gold nanoparticles can be tuned. SAXS measurements reveal an increase of the platelet thickness up to around 14.5 nm, twice the initial value of bare AuNTs. HRTEM micrographs show welding phenomena between densely packed particles on the platelet surface, leading to a crumble formation while preserving the original crystal structure. Crumbles crystallized on top of the platelets enhance the Raman signal by a factor of around 20, and intensify the plasmon‐driven dimerization of 4‐nitrothiophenol (4‐NTP) to 4,4′‐dimercaptoazobenzene in a yield of up to 50 %. The resulting crumbled nanotriangles, with a biopolymer shell and the absorption maximum in the second window for in vivo imaging, are promising candidates for biomedical sensing. KW - SAXS KW - Small-angle X-ray scattering KW - Nanoparticle KW - Gold PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-503977 DO - https://doi.org/10.1002/cplu.201900745 VL - 85 IS - 3 SP - 519 EP - 526 PB - Wiley-VCH Verlag CY - Weinheim AN - OPUS4-50397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kästner, Claudia A1 - Böhmert, Linda A1 - Braeuning, Albert A1 - Lampen, Alfonso A1 - Thünemann, Andreas T1 - Fate of fluorescence labels - Their adsorption and desorption kinetics to silver nanoparticles N2 - Silver nanoparticles are among the most widely used and produced nanoparticles. Because of their frequent application in consumer products, the assessment of their toxicological potential has seen a renewed importance. A Major difficulty is the traceability of nanoparticles in in vitro and in vivo experiments. Even if the particles are labeled, for example, by a fluorescent marker, the dynamic exchange of ligands often prohibits their spatial localization. Our study provides an insight into the adsorption and desorption kinetics of two different fluorescent labels on silver nanoparticles with a core radius of 3 nm by dynamic light scattering, small-angle X-ray scattering, and fluorescence spectroscopy. We used BSA-FITC and tyrosine as examples for common fluorescent ligands. It is shown that the adsorption of BSA-FITC takes at least 3 days, whereas tyrosine adsorbs immediately. The quantitative amount of stabilizer on the particle surface was determined by fluorescence spectroscopy and revealed that the particles are stabilized by a monolayer of BSA-FITC (corresponding to 20 ± 9 molecules), whereas tyrosine forms a multilayered structure consisting of 15900 ± 200 molecules. Desorption experiments show that the BSA-FITC-stabilized particles are ideally suited for application in in vitro and in vivo experiments because the ligand desorption takes several days. Depending on the BSA concentration in the particles surroundings, the rate constant is k = 0.2 per day or lower when applying first order kinetics, that is, 50% of the BSAFITC molecules are released from the particle’s surface within 3.4 days. For illustration, we provide a first application of the fluorescence-labeled particles in an uptake study with two different commonly used cell lines, the human liver cell model HepG2 and the human intestinal cell model of differentiated Caco-2 cells. KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Silver nanoparticles PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-452166 DO - https://doi.org/10.1021/acs.langmuir.8b01305 SN - 1520-5827 SN - 0743-7463 VL - 34 IS - 24 SP - 7153 EP - 7160 PB - American Chemical Society AN - OPUS4-45216 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Navarro, L. A1 - Thünemann, Andreas A1 - Yokosawa, T. A1 - Spiecker, E. A1 - Klinger, D. T1 - Regioselective Seeded Polymerization in Block Copolymer Nanoparticles: Post-Assembly Control of Colloidal Features N2 - Post-assembly modifications are efficient tools to adjust colloidal features of block copolymer (BCP) particles. However, existing methods often address particle shape, morphology, and chemical functionality individually. For simultaneous control, we transferred the concept of seeded polymerization to phase separated BCP particles. Key to our approach is the regioselective polymerization of (functional) monomers inside specific BCP domains. This was demonstrated in striped PS-b-P2VP ellipsoids. Here, polymerization of styrene preferably occurs in PS domains and increases PS lamellar thickness up to 5-fold. The resulting asymmetric lamellar morphology also changes the particle shape, i.e., increases the aspect ratio. Using 4-vinylbenzyl azide as co-monomer, azides as chemical functionalities can be added selectively to the PS domains. Overall, our simple and versatile method gives access to various multifunctional BCP colloids from a single batch of pre-formed particles. KW - Small-angle X-ray scattering KW - SAXS KW - Nanostructure KW - Polymer KW - Nanoparticle PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557246 DO - https://doi.org/10.1002/anie.202208084 SN - 1433-7851 VL - 61 IS - 35 SP - 1 EP - 11 PB - Wiley CY - Weinheim AN - OPUS4-55724 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Navarro, L. A1 - Thünemann, Andreas A1 - Klinger, D. T1 - Solvent Annealing of Striped Ellipsoidal Block Copolymer Particles: Reversible Control over Lamellae Asymmetry, Aspect Ratio, and Particle Surface N2 - Solvent annealing is a versatile tool to adjust the shape and morphology of block copolymer (BCP) particles. During this process, polar solvents are often used for block-selective swelling. However, such water-miscible solvents can induce (partial) solubilization of one block in the surrounding aqueous medium, thus, causing complex structural variations and even particle disassembly. To reduce the complexity in morphology control, we focused on toluene as a nonpolar polystyrene-selective solvent for the annealing of striped polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) ellipsoids. The selective stretching of PS chains produces unique asymmetric lamellae structures, which translate to an increase in the particle aspect ratio after toluene evaporation. Complete reversibility is achieved by changing to chloroform as a nonselective solvent. Moreover, surfactants can be used to tune block-selective wetting of the particle surface during the annealing; for example, a PS shell can protect the internal lamellae structure from disassembly. Overall, this versatile postassembly process enables the tailoring of the structural features of striped colloidal ellipsoids by only using commercial BCPs and solvents. KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Polymer PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543731 DO - https://doi.org/10.1021/acsmacrolett.1c00665 VL - 11 IS - 3 SP - 319 EP - 335 PB - American Chemical Society AN - OPUS4-54373 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hildebrandt, Jana A1 - Taubert, Andreas A1 - Thünemann, Andreas T1 - Synthesis and Characterization of Ultra‐Small Gold Nanoparticles in the Ionic Liquid 1‐Ethyl‐3‐methylimidazolium Dicyanamide, [Emim][DCA] N2 - AbstractWe report on gold clusters with around 62 gold atoms and a diameter of 1.15±0.10 nm. Dispersions of the clusters are long‐term stable for two years at ambient conditions. The synthesis was performed by mixing tetrachloroauric acid (HAuCl4 ⋅ 3 H2O) with the ionic liquid 1‐ethyl‐3‐methylimidazolium dicyanamide ([Emim][DCA]) at temperatures of 20 to 80 °C. Characterization was performed with small‐angle X‐ray scattering (SAXS), UV‐Vis spectroscopy, and MALDI‐TOF mass spectrometry. A three‐stage model is proposed for the formation of the clusters, in which cluster growth from gold nuclei takes place according to the Lifshitz‐Slyozov‐Wagner (LSW) model followed by oriented attachment to form colloidal stable clusters. KW - Reference materials KW - SAXS KW - Gold KW - Nanoparticle KW - Small-angle X-ray scattering KW - Ionic liquid PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-588203 DO - https://doi.org/10.1002/open.202300106 SN - 2191-1363 VL - 44 SP - 1 EP - 19 PB - Wiley AN - OPUS4-58820 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kader, A. A1 - Kaufmann, Jan Ole A1 - Mangarova, D. B. A1 - Moeckel, J. A1 - Brangsch, J. A1 - Adams, L. C. A1 - Zhao, J. A1 - Reimann, C. A1 - Saatz, Jessica A1 - Traub, Heike A1 - Buchholz, R. A1 - Karst, U. A1 - Hamm, B. A1 - Makowski, M. R. T1 - Iron Oxide Nanoparticles for Visualization of Prostate Cancer in MRI N2 - Prostate cancer (PCa) is one of the most common cancers in men. For detection and diagnosis of PCa, non-invasive methods, including magnetic resonance imaging (MRI), can reduce the risk potential of surgical intervention. To explore the molecular characteristics of the tumor, we investigated the applicability of ferumoxytol in PCa in a xenograft mouse model in two different tumor volumes, 500 mm3 and 1000 mm3. Macrophages play a key role in tumor progression, and they are able to internalize iron-oxide particles, such as ferumoxytol. When evaluating T2*-weighted sequences on MRI, a significant decrease of signal intensity between pre- and post-contrast images for each tumor volume (n = 14; p < 0.001) was measured. We, furthermore, observed a higher signal loss for a tumor volume of 500 mm3 than for 1000 mm3. These findings were confirmed by histological examinations and laser ablation inductively coupled plasma-mass spectrometry. The 500 mm3 tumors had 1.5% iron content (n = 14; sigma = 1.1), while the 1000 mm3 tumors contained only 0.4% iron (n = 14; sigma = 0.2). In vivo MRI data demonstrated a correlation with the ex vivo data (R2 = 0.75). The results of elemental analysis by inductively coupled plasma-mass spectrometry correlated strongly with the MRI data (R2 = 0.83) (n = 4). Due to its long retention time in the blood, biodegradability, and low toxicity to patients, ferumoxytol has great potential as a contrast agent for visualization PCa. KW - Imaging KW - Nanoparticle KW - Cancer KW - Iron oxide KW - ICP-MS KW - Magnetic resonance imaging PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550075 DO - https://doi.org/10.3390/cancers14122909 VL - 14 IS - 12 SP - 1 EP - 13 PB - MDPI CY - Basel, Switzerland AN - OPUS4-55007 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute A1 - Meermann, Björn A1 - Koch, Matthias A1 - Weller, Michael G. T1 - Editorial: Analytical methods and applications in materials and life sciences N2 - Current trends in materials and life sciences are flanked by the need to push detection limits to single molecules or single cells, enable the characterization of increasingly complex matrices or sophisticated nanostructures, speed up the time of analysis, reduce instrument complexity and costs, and improve the reliability of data. This requires suitable analytical tools such as spectroscopic, separation and imaging techniques, mass spectrometry, and hyphenated techniques as well as sensors and their adaptation to application-specific challenges in the environmental, food, consumer product, health sector, nanotechnology, and bioanalysis. Increasing concerns about health threatening known or emerging pollutants in drinking water, consumer products, and food and about the safety of nanomaterials led to a new awareness of the importance of analytical sciences. Another important driver in this direction is the increasing demand by legislation, particularly in view of the 17 sustainable development goals by the United Nations addressing clean energy, industry, and innovation, sustainable cities, clean water, and responsible consumption and production. In this respect, also the development of analytical methods that enable the characterization of material flows in production processes and support recycling concepts of precious raw materials becomes more and more relevant. In the future, this will provide the basis for greener production in the chemical industry utilizing recycled or sustainable starting materials. This makes analytical chemistry an essential player in terms of the circular economy helping to increase the sustainability of production processes. In the life sciences sector, products based on proteins, such as therapeutic and diagnostic antibodies, increase in importance. These increasingly biotechnologically produced functional biomolecules pose a high level of complexity of matrix and structural features that can be met only by highly advanced methods for separation, characterization, and detection. In addition, metrological traceability and target definition are still significant challenges for the future, particularly in the life sciences. However, innovative reference materials as required for the health and food sector and the characterization of advanced materials can only be developed when suitable analytical protocols are available. The so-called reproducibility crisis in sciences underlines the importance of improved measures of quality control for all kinds of measurements and material characterization. This calls for thorough method validation concepts, suitable reference materials, and regular interlaboratory comparisons of measurements as well as better training of scientists in analytical sciences. The important contribution of analytical sciences to these developments is highlighted by a broad collection of research papers, trend articles, and critical reviews from these different application fields. Special emphasis is dedicated to often-overlooked quality assurance and reference materials. T2 - 150 years BAM: Science with impact CY - Berlin, Germany DA - 01.01.2021 KW - Analysis KW - Life sciences KW - Analytical sciences KW - Quality assurance KW - Reference material KW - Fluorescence KW - Nanoparticle KW - Sensor KW - Material sciences KW - Pollutant KW - Environment KW - Method KW - Limit of detection KW - 150th anniversary KW - ABC KW - BAM KW - Collection KW - Editorial KW - Special issue KW - Bundesanstalt für Materialforschung und -prüfung KW - Jahrestag PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550720 DO - https://doi.org/10.1007/s00216-022-04082-8 SN - 1618-2642 SN - 1618-2650 VL - 414 IS - Topical collection: Analytical methods and applications in the materials and life sciences SP - 4267 EP - 4268 PB - Springer CY - Berlin AN - OPUS4-55072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -