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 - Hussein, S. A1 - Kühl, A. A. A1 - Golusda, L. A1 - Plattner, C. A1 - Heinze, N. A1 - Sturm, G. A1 - Freise, C. A1 - Traub, Heike A1 - Schannor, Mathias A1 - Trajanoski, Z. A1 - Taupitz, M. A1 - Siegmund, B. A1 - Paclik, D. T1 - Phenotype and function of human monocytes remain mainly unaffected by very small superparamagnetic iron oxide particles N2 - The field of medical application of organic or inorganic nanoparticles is extensive. Medical nanoparticles offer benefits but pose risks. For safe use in diagnostics and therapy, they should be inert, non-immunogenic, non-aggregating, and avoid long-term accumulation in sensitive tissues like bone marrow or the brain. We have developed in-house very small superparamagnetic iron oxide nanoparticles (VSOP), 7 nm in size, which have been successfully used in preclinical magnetic resonance imaging (MRI) to detect intestinal inflammation, neuroinflammation and atherosclerosis. This study examines nanoparticle effects on human blood cells focusing on monocytes in vitro as a first step toward clinical application. Whole blood and monocytes from healthy donors and patients with inflammatory bowel disease were treated with VSOP in vitro and analyzed for changes in their transcriptome, phenotype and function. RNA sequencing of monocytes identified the transferrin receptor as one of the most significantly downregulated genes after VSOP treatment, likely to limit iron uptake. Whereas whole blood RNA sequencing showed significant changes only in three non-coding genes. CyTOF analysis confirmed that VSOP-treated monocytes remain inactive, with no increased proliferation or altered migration. Metabolically, VSOP uptake enhanced the oxygen consumption rate. This effect was likely due to phagocytosis rather than effects mediated by the VSOP itself, as phagocytosis of latex beads showed comparable results. In summary, the analysis of peripheral blood mononuclear cells and monocytes suggests that VSOP treatment has no major impact on immune cell phenotype or function indicating VSOP as a promising diagnostic tool in MRI for inflammatory bowel disease. KW - Imaging KW - Nanoparticle KW - Monocytes KW - Contrast agent KW - Diagnostics KW - ICP-MS KW - LA-ICP-MS KW - VSOP PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-632012 DO - https://doi.org/10.3389/fnano.2025.1584000 SN - 2673-3013 VL - 7 SP - 1 EP - 16 PB - Frontiers Media CY - Lausanne AN - OPUS4-63201 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geißler, Daniel A1 - Wegner, Karl David A1 - Fischer, C. A1 - Resch-Genger, Ute T1 - Exploring Simple Particle-Based Signal Amplification Strategies in a Heterogeneous Sandwich Immunoassay with Optical Detection N2 - Heterogeneous sandwich immunoassays are widely used for biomarker detection in bioanalysis and medical diagnostics. The high analyte sensitivity of the current “gold standard” enzyme-linked immunosorbent assay (ELISA) originates from the signal-generating enzymatic amplification step, yielding a high number of optically detectable reporter molecules. For future point-of-care testing (POCT) and point-of-need applications, there is an increasing interest in more simple detection strategies that circumvent time-consuming and temperature-dependent enzymatic reactions. A common concept to aim for detection limits comparable to those of enzymatic amplification reactions is the usage of polymer nanoparticles (NP) stained with a large number of chromophores. We explored different simple NP-based signal amplification strategies for heterogeneous sandwich immunoassays that rely on an extraction-triggered release step of different types of optically detectable reporters. Therefore, streptavidinfunctionalized polystyrene particles (PSP) are utilized as carriers for (i) the fluorescent dye coumarin 153 (C153) and (ii) hemin (hem) molecules catalyzing the luminol reaction enabling chemiluminescence (CL) detection. Additionally, (iii) NP labeling with hemin-based microperoxidase MP11 was assessed. For each amplification approach, the PSP was first systematically optimized regarding size, loading concentration, and surface chemistry. Then, for an immunoassay for the inflammation marker C- eactive protein (CRP), the analyte sensitivity achievable with optimized PSP ystems was compared with the established ELISA concept for photometric and CL detection. Careful optimization led to a limit of detection (LOD) of 0.1 ng/mL for MP11-labeled PSP and CL detection, performing similarly well to a photometric ELISA (0.13 ng/mL), which demonstrates the huge potential of our novel assay concept. KW - Nanoparticle KW - Fluorescence KW - Immunoassay KW - Quality assurance KW - Antibody KW - Polymer KW - Dye KW - Signal enhancement KW - CRP KW - Biosensing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597853 DO - https://doi.org/10.1021/acs.analchem.3c03691 SN - 1520-6882 VL - 96 IS - 13 SP - 5078 EP - 5085 PB - American Chemical Society CY - Columbus, Ohio AN - OPUS4-59785 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Amouroux, B. A1 - Eftekhari, A. A1 - Roux, C. A1 - Micheau, J. A1 - Roblin, P. A1 - Pasturel, M. A1 - Gauffre, F. A1 - Würth, Christian A1 - Resch-Genger, Ute A1 - Sliwa, M. A1 - Bouchet, A. A1 - Coudret, C. T1 - Synthesis and Emission Dynamics of Sub-3 nm Upconversion Nanoparticles N2 - Reducing the size of upconversion nanoparticles (UCNPs) down to a few nm yields luminescent materials containing a very small number of emitters. Considering the bottom limit of one activator per particle ultrasmall UCNPs offer an unprecedented platform to study the contributions of the energy transfers at play in upconversion luminescence. Maintaining detectable emission despite the limited number of emitting ions and the high surface-to-volume ratio requires suitable particle architectures. Na(Gd-Yb)F4:Tm3+ emissive sub-3 nm diameter 𝜷-phase UCNPs are prepared using a gadolinium-rich composition in situ mixing of the precursors and a microwave high-temperature cycling sequence allowing precise control of the particle size and dispersity. These cores are coated with a NaGdF4 inert shell to minimize the deleterious influence of surface quenching (SQ). Time-resolved luminescence measurements combining standard NIR excitation of the Yb3+ sensitizer and direct UV excitation of the Tm3+ activator are performed to quantify cross relaxation and surface quenching processes. The fine tuning of the number of activators per particle via an optimized synthesis pathway along with the use of an appropriate excitation scheme enabled to provide an accurate analysis of the different mechanisms at play in these model nanoparticles and to characterize the structure of the core-shell architecture. KW - Lanthanide KW - Nanoparticle KW - Luminescence KW - Quantitative spectroscopy KW - Quantum yield KW - Energy transfer KW - Quality assurance KW - Synthesis KW - Surface modification KW - Photophysics PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-606877 DO - https://doi.org/10.1002/adom.202303283 SN - 2195-1071 SP - 1 EP - 13 AN - OPUS4-60687 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Billimoria, K. A1 - Andresen, Elina A1 - Resch-Genger, Ute A1 - Goenaga-Infante, H. T1 - A Strategy for Quantitative Imaging of Lanthanide Tags in A549 Cells Using the Ratio of Internal Standard Elements N2 - One remaining handicap for spatially resolved elemental quantification in biological samples is the lack of a suitable internal standard (IS) that can be reliably measured across both calibration standards and samples. In this work, multielement quantitative intracellular imaging of cells tagged with lanthanide nanoparticles containing key lanthanides, e.g., Eu and Ho, is described using a novel strategy that uses the ratio of IS elements and LA-ICP-TOFMS analysis. To achieve this, an internal standard layer is deposited onto microscope slides containing either gelatin calibration standards or Euand Ho-tagged cell samples. This IS layer contains both gallium (Ga) and indium (In). Monitoring either element as an IS individually showed significant variability in intensity signal between sample or standards prepared across multiple microscope slides, which is indicative of the difficulties in producing a homogeneous film at intracellular resolution. However, normalization of the lanthanide signal to the ratio of the IS elements improved the calibration correlation coefficients from 0.9885 to 0.9971 and 0.9805 to 0.9980 for Eu and Ho, respectively, while providing a consistent signal to monitor the ablation behavior between standards and samples. By analyzing an independent quality control (QC) gelatin sample spiked with Eu and Ho, it was observed that without normalization to the IS ratio the concentrations of Eu and Ho were highly biased by approximately 20% in comparison to the expected values. Similarly, this overestimation was also observed in the lanthanide concentration distribution of the cell samples in comparison with the normalized data. KW - Nanoparticle KW - Nano KW - Luminescence KW - Quality assurance KW - Synthesis KW - Standardization KW - Reference material KW - ICP-MS KW - LA-ICP-MS KW - Quantification KW - Bioimaging PY - 2024 DO - https://doi.org/10.1021/acs.analchem.4c02763 SN - 0003-2700 VL - 96 IS - 30 SP - 12570 EP - 12576 AN - OPUS4-60768 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - 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 - Somasundaram, S. K. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Emmerling, Franziska A1 - Krishnan, S. A1 - Senthilkumar, K. A1 - Joseyphus, R.J. T1 - New insights into pertinent Fe-complexes for the synthesis of iron via the instant polyol process N2 - Chemically synthesized iron is in demand for biomedical applications due to its large saturation magnetization compared to iron oxides. The polyol process, suitable for obtaining Co and Ni particles and their alloys, is laborious in synthesizing Fe. The reaction yields iron oxides, and the reaction pathway remains unexplored. This study shows that a vicinal polyol, such as 1,2-propanediol, is suitable for obtaining Fe rather than 1,3-propanediol owing to the formation of a reducible Fe intermediate complex. X-ray absorption spectroscopy analysis reveals the ferric octahedral geometry and tetrahedral geometry in the ferrous state of the reaction intermediates in 1,2-propanediol and 1,3-propanediol, respectively. The final product obtained using a vicinal polyol is Fe with a γ-Fe2O3 shell, while the terminal polyol is favourable for Fe3O4. The distinct Fe–Fe and Fe–O bond lengths suggest the presence of a carboxylate group and a terminal alkoxide ligand in the intermediate of 1,2-propanediol. A large Fe–Fe bond distance suggests diiron complexes with bidentate carboxylate bridges. Prominent high-spin and low-spin states indicate the possibility of transition, which favors the reduction of iron ions in the reaction using 1,2-propanediol. KW - XAS KW - Nanoparticle PY - 2023 DO - https://doi.org/10.1039/D3CP01969A SN - 1463-9076 VL - 25 IS - 33 SP - 21970 EP - 21980 PB - Royal Society of Chemistry (RSC) AN - OPUS4-58073 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zutta Villate, J. M. A1 - Viviana Rojas, J. A1 - Hahn, Marc Benjamin A1 - Anselmo Puerta, J. T1 - Synthesis of 198Au nanoparticles sub 10 nm due optimization on local dose by Monte Carlo simulations for cancer treatment N2 - To enhance the biological effects of radiation damage in cancerous cells, we present an alternative approach to the use of gold nanoparticles (AuNP), focusing on the synthesis and characterization of highly monodisperse, spherical radioactive gold nanoparticles 198AuNP. The size of the AuNP size was optimized with the help of Geant4/TOPAS particle scattering simulations, and energy deposition per nm3 per decay for varying radii (2–10 nm) was evaluated. This work is the foundation for ongoing experimental work to evaluate cell death induced by 198AuNP which aims for the use of radioactive gold nanoparticles in cancer treatment. KW - AuNP KW - Beta decay KW - Beta particle KW - Brachytherapy KW - Cancer treatment KW - Nanoparticles KW - Nanoparticle KW - DNA KW - DNA damage KW - Dosimetry KW - Energy deposit KW - Gamma ray KW - Geant4 KW - Geant4-DNA KW - Gold Nanoparticles KW - LEE KW - Low energy electrons KW - MCS KW - Microdosimetry KW - Monte-Carlo simulation KW - NP KW - Synthesis KW - TEM KW - OH radicals KW - Particle scattering KW - Radiation damage KW - Radiationtherapy KW - Radioactive decay KW - Radiolysis KW - Simulation KW - TOPAS KW - TOPAS-nbio PY - 2022 DO - https://doi.org/10.1007/s10967-022-08355-5 SN - 1588-2780 SP - 1 EP - 9 PB - Springer Nature AN - OPUS4-55132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grauel, Bettina A1 - Würth, Christian A1 - Homann, C. A1 - Krukewitt, Lisa A1 - Andresen, Elina A1 - Roik, Janina A1 - Recknagel, Sebastian A1 - Haase, M. A1 - Resch-Genger, Ute T1 - Volume and surface effects on two-photonic and three-photonic processes in dry co-doped upconversion nanocrystals N2 - Despite considerable advances in synthesizing high-quality core/shell upconversion (UC) nanocrystals (NC; UCNC) and UCNC photophysics, the application of near-infrared (NIR)-excitable lanthanide-doped UCNC in the life and material sciences is still hampered by the relatively low upconversion luminescence (UCL) of UCNC of small size or thin protecting shell. To obtain deeper insights into energy transfer and surface quenching processes involving Yb3+ and Er3+ ions, we examined energy loss processes in differently sized solid core NaYF4 nanocrystals doped with either Yb3+ (YbNC; 20% Yb3+) or Er3+ (ErNC; 2% Er3+) and co-doped with Yb3+ and Er3+ (YbErNC; 20% Yb3+ and 2% Er3+) without a surface protection shell and coated with a thin and a thick NaYF4 shell in comparison to single and co-doped bulk materials. Luminescence studies at 375 nm excitation demonstrate backenergy transfer (BET) from the 4G11/2 state of Er3+ to the 2F5/2 state of Yb3+, through which the red Er3+ 4F9/2 state is efficiently populated. Excitation power density (P)-dependent steady state and time-resolved photoluminescence measurements at different excitation and emission wavelengths enable to separate surface-related and volume-related effects for two-photonic and threephotonic processes involved in UCL and indicate a different influence of surface passivation on the green and red Er3+ emission. The intensity and lifetime of the latter respond particularly to an increase in volume of the active UCNC core. We provide a threedimensional random walk model to describe these effects that can be used in the future to predict the UCL behavior of UCNC. KW - Nano KW - Nanomaterial KW - Upconversion KW - Nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Pphotophysics KW - Lifetime KW - Sensor KW - Excitation KW - Power density KW - Single particle KW - Brightness KW - NIR KW - Mechanism KW - Modeling KW - Simulation KW - Energy transfer PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-535317 DO - https://doi.org/10.1007/s12274-021-3727-y SN - 1998-0124 VL - 15 IS - 3 SP - 2362 EP - 2373 PB - Springer AN - OPUS4-53531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -