TY - JOUR
A1 - You, Yi
A1 - Danischewski, Julia
A1 - Molnar, Brian
A1 - Riedel, Jens
A1 - Shelley, Jacob
T1 - Manipulation of Gaseous Ions with Acoustic Fields at Atmospheric Pressure
N2 - The ability to controllably move gaseous ions is an essential aspect of ion-based spectrometry (e.g., mass spectrometry and ion mobility spectrometry) as well as materials processing. At higher pressures, ion motion is largely governed by diffusion and multiple collisions with neutral gas molecules. Thus, high-pressure ion optics based on electrostatics require large fields, radio frequency drives, complicated geometries, and/or partially transmissive grids that become contaminated. Here, we demonstrate that low-power standing acoustic waves can be used to guide, block, focus, and separate beams of ions akin to electrostatic ion optics. Ions preferentially travel through the static-pressure regions (“nodes”) while neutral gas does not appear to be impacted by the acoustic field structure and continues along a straight trajectory. This acoustic ion manipulation (AIM) approach has broad implications for ion manipulation techniques at high pressure, while expanding our fundamental understanding of the behavior of ions in gases.
KW - Ion mobility spectrometry
KW - Acoustic
KW - Mass spectrometry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600704
DO - https://doi.org/10.1021/jacs.4c01224
SP - 1
EP - 6
PB - ACS Publications
AN - OPUS4-60070
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Riedel, Jens
A1 - Hufgard, Josefin
A1 - You, Yi
T1 - LIBS at high duty-cycles: effect of repetition rate and temporal width on the excitation laser pulses
N2 - Laser-induced breakdown spectroscopy (LIBS) is becoming a more mature technology every year with new variants such as laser ablation molecular isotopic spectrometry, reheating by various discharge techniques, and multiple pulse excitation schemes, in which sometimes lasers of different pulse lengths are used. However, lasers with inherent parameters like pulse length and repetition rate are still almost exclusively employed. Recent years have witnessed the advent of novel high-repetition-rate laser concepts for machining processes, like welding, milling, and engraving. Here, a comprehensive study of single-pulse LIBS spectra of a single aluminum target is presented to showcase the applicability of flexible high duty-cycle master oscillator power amplifier (MOPA) lasers. Although traditional flashlamp-pumped Fabry–Pérot lasers only permit a variation in the pulse energy and are operated at very low duty-cycles, MOPA lasers add repetition rate and pulse length as variable parameters. A thorough analysis of the temporal plasma behavior revealed the emission dynamic to closely match the excitation laser pulse pattern. An aluminum sample’s spectral response was shown to be significantly impacted by variations in both rate and length. Although the spectral emission strength of the elemental lines of Al, Sr, and Ca all peaked at slightly different parameter settings, the strongest impact was found on the relative abundance of molecular AlO bands. Unlike in previous laser ablation molecular isotopic spectrometry (LAMIS) publications, the latter could be readily detected with a good intensity and well-resolved spectral features without any temporal gating of the detector. This finding, together with the fact that MOPA lasers are both inexpensive and dependable, makes for a promising combination for future studies including the detection of diatomic band structures.
KW - Laser-induced breakdown spectroscopy
KW - LIBS
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-583300
DO - https://doi.org/10.3389/fphy.2023.1241533
SN - 2296-424X
VL - 11
SP - 1
EP - 8
AN - OPUS4-58330
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kalmbach, J.
A1 - Wang, Cui
A1 - You, Yi
A1 - Förster, C.
A1 - Schubert, H.
A1 - Heinze, K.
A1 - Resch-Genger, Ute
A1 - Seitz, M.
T1 - Near-IR to near-IR upconversion luminescence in molecular chromium ytterbium salts
N2 - Upconversion photoluminescence in hetero-oligonuclear metal complex architectures featuring organic ligands is an interesting but still rarely observed phenomenon, despite its great potential from a basic research and application perspective. In this context, a new photonic material consisting of molecular chromium(III) and ytterbium(III) complex Ions was developed that exhibits excitation-power density-dependent cooperative sensitization of the chromium-centered 2E/2T1 phosphorescence at approximately 775 nm after excitation of the ytterbium band 2F7/2!2F5/2 at approximately 980 nm in the solid state at ambient temperature. The upconversion process is insensitive to atmospheric oxygen and can be observed in the presence of water molecules in the crystal lattice.
KW - Upconversion
KW - Lanthanide
KW - Photoluminescence
KW - Quantum yield
KW - Photophysics
KW - Lifetime
KW - Sensor
KW - NIR
KW - Cr(III)
KW - Yb(III) complex
KW - Crystal
KW - Triplet-triplet annihilation
KW - Sensitization
KW - Light harvesting
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512619
DO - https://doi.org/10.1002/anie.202007200
SN - 1433-7851
SN - 1521-3773
VL - 59
IS - 42
SP - 18804
EP - 18808
PB - Wiley
CY - Weinheim
AN - OPUS4-51261
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Xue, Boyang
A1 - Wang, Zhangjun
A1 - Zhu, Tao
A1 - Gu, Yezhen
A1 - Sun, Weihong
A1 - Chen, Chao
A1 - Li, Zhigang
A1 - Riedel, Jens
A1 - You, Yi
T1 - High repetition-rate laser-induced breakdown spectroscopy combined with two-dimensional correlation method for analysis of sea-salt aerosols
N2 - Laser-induced breakdown spectroscopy (LIBS) offers a tantalizing glimpse into real-time, on-the-spot aerosol analysis. Yet, the reliance on traditional lasers, with their limitations in energy and frequency, hampers optimal sample handling, dissociation, and excitation. To address those challenges, we propose a novel tactic: utilize a high repetition-rate (rep.-rate) laser with low pulse energy in combination with the two-dimensional correlation (2D-corr.) technique for sea-salt aerosols analyses. By examining the emission patterns from both the laser pulse train and individual pulses, we recognize distinctive analyte-specific rep.-rate responses, which allowed spectral reconstruction of analytes, avoiding background interferences. This discovery enabled the rep.-rate modulation for a 2D-corr. spectroscopy workflow. Consequently, we successfully differentiated between particle-related and air-species-related spectral components, obviating expensive spectrometers or intensified image detectors. For instance, the Na I at 589 nm stemming from aerosols exhibited an entirely different correlation contribution compared to O I at 777 nm, resulting in reconstructed clean aerosol-spectra without spectral peaks originated from air species. This 2D-corr. aerosol LIBS approach shows promising analytical potential streamlining aerosol particle analysis.
KW - LIBS
KW - Aerosol
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613392
DO - https://doi.org/10.1016/j.sab.2024.107048
SN - 0584-8547
VL - 221
SP - 1
EP - 8
PB - Elsevier
AN - OPUS4-61339
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Li, Xunyu
A1 - Riedel, Jens
A1 - You, Yi
T1 - Spectrally resolved lithium isotope quantification through high-resolution spatial heterodyne spectrometry
N2 - Isotope ratio determination of lithium is increasingly important in fields ranging from geochemistry to battery diagnostics. While mass spectrometry remains the gold standard, it is costly, cumbersome, and incompatible with portable or inline implementations. Optical emission spectroscopy presents an appealing alternative. However, it is traditionally limited by insufficient spectral resolution or resolving power to separate lithium isotope emissions due to their generalized designs for a wide spectral range; this often requires overly complicated algorithms to overcome the instrumental drawbacks. (79)
Results Here, we report a high-resolution optical method for lithium isotope quantification using a custom-built spatial heterodyne spectrometer (SHS) combined with a reduced-pressure glow discharge source. This configuration yielded a resolving power of 189,000 and enabled baseline resolution of lithium d-line emission features even without the need for preliminary data processing. Despite the inherent low sensitivity of SHS, a detection limit of 30 pmol was achieved using a standard industrial camera. To improve quantitative accuracy, we introduced a deconvolution-based spectral lineshape recovery technique alongside a bootstrapping-based error propagation strategy. These methods facilitated robust isotope ratio calibration using both peak-height and peak-area metrics. The SHS platform additionally enabled the determination of relative transition probabilities, suggesting the feasibility of calibration-free operation.
This work demonstrates the practical viability of SHS for high-specificity, high-resolution lithium isotope analysis. The approach is compact, potentially field-deployable, and adaptable to other elements with optically resolvable isotope shifts, offering a route toward accessible and calibration-free optical isotopic analyses.
KW - SHS
KW - Isotope
KW - High-resolution spectroscopy
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635139
DO - https://doi.org/10.1016/j.aca.2025.344329
SN - 1873-4324
VL - 1368
SP - 1
EP - 8
PB - Elsevier B.V.
AN - OPUS4-63513
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mohan, M.
A1 - Prochazka, D.
A1 - You, Yi
A1 - Riedel, Jens
A1 - Gornushkin, Igor
A1 - Rocnakova, I.
A1 - Papula, M.
A1 - Porízka, P.
A1 - Kaizer, J.
T1 - Investigating plasma morphology at material boundaries under varying ambient pressures
N2 - Laser-Induced Breakdown Spectroscopy (LIBS) is a widely used technique for elemental analysis. The analysis of the obtained LIBS spectra generally assumes plasma homogeneity. However, using focused laser beams for interrogation, LIBS probes materials on the microscale and is, thus, prone to artefacts from sample heterogeneities on the micrometer scale. An ablation at a material boundary of two matrices may result in a significant inhomogeneity in the plasma plume, which can severely impact the accuracy of quantitative analysis. Since this propagation of the surface morphology into the plasma plume is driven by the plasma expansion, its final impact is strongly pressure dependent. This study examines the influence of varying ambient pressures (7–1000 mbar) on plasma morphology, spectral characteristics, and key plasma properties such as electron number density at a well-defined Cu–Sn boundary, in comparison with the results obtained using homogeneous alloys. Several approaches of plasma imaging with bandpass filters, spectroscopy, and Radon transform-based 3D reconstruction were employed to analyze elemental distribution, signal-to-noise (SNR) and signal-to-background (SBR) ratios, as well as electron number densities. The 3D reconstructions revealed a pronounced plasma asymmetry for the ablation at the material boundary, in contrast to the near-axial symmetry observed for the ablation of homogeneous alloys. At lower pressures, this distinct elemental separation in plasma persisted, while higher pressures led to an increased collisional mixing and homogenization. SNR and SBR were consistently lower for ablation at the boundary compared to homogeneous samples. These findings highlight how boundary ablation contributes to plasma inhomogeneities in LIBS analysis of heterogeneous materials and emphasize the need to account for these
effects when using LIBS for elemental mapping of fine heterogeneous structures.
KW - Laser-induced breakdown spectroscopy
KW - Plasma inhomogeneity
KW - Plasma tomography
KW - Radon transform
KW - Material boundaries
KW - Ambient pressure effects
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634777
DO - https://doi.org/10.1016/j.talanta.2025.128377
SN - 1873-3573
VL - 295
SP - 1
EP - 8
PB - Elsevier B.V.
AN - OPUS4-63477
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - You, Yi
A1 - Xue, Boyang
A1 - Riedel, Jens
T1 - Enhancement of LIBS plasma in air with organic solvent vapors
N2 - Laser-induced breakdown spectroscopy (LIBS) offers versatile, field-deployable elemental analysis; however, compact, high-repetition-rate nanosecond laser systems typically face constraints in power consumption and size, often compromising emission intensity and thus analytical performance. We demonstrate a significant improvement in LIBS signals through the controlled introduction of common organic solvent vapors into a sheath gas, with a diode-pumped solid-state laser (1064 nm, 2–28 kHz repetition rate, 450–600-μJ pulse energy). Optical and acoustic diagnostics reveal up to ca. 40-fold enhancement of the N II emission line at 567 nm when ambient air serves as the analyte. Maximal enhancement occurs at intermediate repetition rates of ca. 15 kHz, particularly at pulse energies approaching the optical breakdown threshold; this observation suggests a viable strategy for operating LIBS at lower pulse energies and higher repetition rates. Enhancement effects scale jointly with both vapor pressure and ionization energy of the organic species, with acetone and toluene markedly outperforming methanol and isopropanol. These findings provide a rational foundation for significantly improving the analytical performance of portable LIBS instruments without exceeding platform-specific constraints.
KW - LIBS
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653758
DO - https://doi.org/10.1016/j.sab.2025.107309
SN - 0584-8547
VL - 236
SP - 1
EP - 6
PB - Elsevier B.V.
AN - OPUS4-65375
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wittwer, Philipp
A1 - Roesch, Philipp
A1 - Vogel, Christian
A1 - Simon, Fabian
A1 - Gehrenkemper, Lennart
A1 - Feldmann, Ines
A1 - Simon, Franz-Georg
T1 - Less Is More: Influence of Cross-Linking Agent Concentration on PFOS Adsorption in Chitosan
N2 - As a result of the continuous use of persistent per- and polyfluoroalkyl substances (PFAS), e.g., in aviation firefighting foams, contamination with PFAS has been found in soil, groundwater, and surface water around thousands of industrial and military installations. Due to their harmful (environmental) potential, further dispersion in the environment needs to be stopped, which can be achieved by appropriate absorption materials. In this work, the influence of the cross-linking agent epichlorohydrin (ECH) concentration on the perfluorooctanesulfonic acid (PFOS) adsorption capacity of chitosan gel was investigated. It was found that higher ECH concentration during the cross-linking step decreases the PFOS adsorption capacity of the cross-linked chitosan gel from 0% to 4% ECH solution by about 15%. Using a concentration of 1%, ECH resulted still in an acid-stable material, and a maximum PFOS loading capacity of 4.04 mmol/g was obtained, one of the highest described in the literature. Furthermore, we used a rapid small-scale column test to compare the PFOS adsorption capacity of chitosan and activated carbon, each in both milled and unmilled form. Unmilled chitosan showed the highest PFOS adsorption capacity considering adsorption material dry masses (>0.9 and <0.4 mmol/g for both types of chitosan and activated carbon, respectively). Milled activated carbon proved to be the better adsorption material, considering the fixed volume of the adsorber (>99.9% PFOS adsorbed). Overall, the cross-linking agent concentration in chitosan is a crucial factor influencing its PFOS absorption potential. Our results feature cross-linked chitosan as an effective economic and ecologic alternative for PFOS adsorption in aqueous solutions.
KW - Combustion Ion Chromatography
KW - Per- and Polyfluoroalkyl substances (PFAS)
KW - Remediation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618406
DO - https://doi.org/10.3390/app142311145
VL - 14
IS - 23
SP - 1
EP - 13
PB - MDPI
AN - OPUS4-61840
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schutter, Jan David
A1 - Eberhardt, Karl
A1 - Elert, Anna Maria
A1 - Radnik, Jörg
A1 - Geißler, Daniel
A1 - Özcan Sandikcioglu, Özlem
T1 - Synthesis and characterization of lipopolysaccharide (LPS) anchored polystyrene microparticles as a synthetic model system for attachment studies
N2 - Outer membrane lipopolysaccharides (LPS) play a crucial role in determining attachment behavior and pathogenicity of bacteria. The aim of this study was to develop a simple procedure for anchoring bacterial lipopolysaccharides to polystyrene (PS) microparticles as a model system for in situ attachment studies. By using a swellcapture methodology, commercially available LPS of Pseudomonas aeruginosa (strain ATCC 27316 serotype 10.22) was anchored onto PS microparticles in a proof-of-concept study. A detailed chemical and morphological characterization has proven the success of LPS incorporation. It was shown that the coverage and structure of the LPS film was concentration dependent. The procedure can easily be adapted to LPS of other bacterial strains to generate a synthetic model toolkit for attachment studies.
KW - Bacterial lipopolysaccharides
KW - Pseudomonas aeruginosa
KW - Polystyrene microparticles
KW - Swell-capture
KW - Biomimicry
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-579818
DO - https://doi.org/10.1016/j.colsurfb.2023.113301
SN - 0927-7765
VL - 226
SP - 1
EP - 7
PB - Elsevier B.V.
AN - OPUS4-57981
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wetzel, Annica
A1 - von der Au, Marcus
A1 - Dietrich, P. M.
A1 - Radnik, Jörg
A1 - Özcan Sandikcioglu, Özlem
A1 - Witt, Julia
T1 - The comparison of the corrosion behavior of the CrCoNi medium entropy alloy and CrMnFeCoNi high entropy alloy
N2 - This work presents the determination of the corrosion characteristics of CrCoNi (medium entropy alloy) and CrMnFeCoNi (high entropy alloy) in 0.1 M NaCl and 0.1 M H2SO4. The morphology and chemical composition of the oxide layers formed on CrCoNi and CrMnFeCoNi were comparatively analyzed by scanning Kelvin probe microscopy (SKPFM) and scanning electron microscopy (SEM) and supported with chemical analysis by means of inductively coupled plasma mass spectrometry (ICP-MS) and X-Ray photoelectron spectroscopy (XPS). The analysis of the 3p core level peaks showed that the oxide layer (native and after anodic passivation) on CrCoNi consisted mainly of Cr oxides, while the oxide layer on CrMnFeCoNi was primarily composed of a mixture of Cr and Fe oxides. In addition, XPS was utilized to assess the oxide layer thicknesses. These results were compared to the thicknesses obtained by means of electrochemical impedance spectroscopy (EIS), with both approaches yielding values up to about 4 nm depending on the electrolyte and the alloy. Cyclic polarization measurements indicated superior corrosion resistance of CrCoNi in both aqueous environments compared to CrMnFeCoNi, as well as to AISI 304 stainless steel.
KW - Medium entropy alloy
KW - High entropy alloy
KW - SKPFM
KW - XPS
KW - Passivation
KW - Corrosion
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559902
DO - https://doi.org/10.1016/j.apsusc.2022.154171
SN - 0169-4332
VL - 601
SP - 1
EP - 10
PB - Elsevier B.V.
AN - OPUS4-55990
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wen, Keqing
A1 - Gorbushina, Anna
A1 - Schwibbert, Karin
A1 - Bell, Jérémy
T1 - Microfluidic platform with precisely controlled hydrodynamic parameters and integrated features for generation of microvortices to accurately form and monitor biofilms in flow
N2 - Microorganisms often live in habitats characterized by fluid flow, and their adhesion to surfaces in industrial systems or clinical settings may lead to pipe clogging, microbially influenced corrosion, material deterioration, food spoilage, infections, and human illness. Here, a novel microfluidic platform was developed to investigate biofilm formation under precisely controlled (i) cell concentration, (ii) temperature, and (iii) flow conditions. The developed platform central unit is a single-channel microfluidic flow cell designed to ensure ultrahomogeneous flow and condition in its central area, where features, e.g., with trapping properties, can be incorporated. In comparison to static and macroflow chamber assays for biofilm studies, microfluidic chips allow in situ monitoring of biofilm formation under various flow regimes and have better environment control and smaller sample requirements. Flow simulations and experiments with fluorescent particles were used to simulate bacteria flow in the platform cell for calculating flow velocity and direction at the microscale level. The combination of flow analysis and fluorescent strain injection in the cell showed that microtraps placed at the center of the channel were efficient in capturing bacteria at determined positions and to study how flow conditions, especially microvortices, can affect biofilm formation. The microfluidic platform exhibited improved performances in terms of homogeneity and robustness for in vitro biofilm formation. We anticipate the presented platform to be suitable for broad, versatile, and high-throughput biofilm studies at the microscale level.
KW - Topographical pattern
KW - E. coli
KW - Fluorescence
KW - Bacteria trapping
KW - Particle velocimetry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610450
DO - https://doi.org/10.1021/acsbiomaterials.4c00101
SN - 2373-9878
VL - 10
IS - 7
SP - 4626
EP - 4634
PB - ACS Publ.
CY - Washington, DC
AN - OPUS4-61045
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wetzel, Annica
A1 - Morell, Daniel
A1 - von der Au, Marcus
A1 - Wittstock, Gunther
A1 - Özcan Sandikcioglu, Özlem
A1 - Witt, Julia
T1 - Transpassive Metal Dissolution vs. Oxygen Evolution Reaction: Implication for Alloy Stability and Electrocatalysis
T1 - Transpassive Metallauflösung vs. Sauerstoffentwicklung:
Auswirkungen auf Legierungsstabilität und Elektrokatalyse
N2 - Multi-principal element alloys (MPEAs) are gaining interest in corrosion and electrocatalysis research due to their electrochemical stability across a broad pH range and the design flexibility they offer. Using the equimolar CrCoNi alloy, we observe significant metal dissolution in a corrosive electrolyte (0.1 M NaCl, pH 2) concurrently with the oxygen evolution reaction (OER) in the transpassive region despite the absence of hysteresis in polarization curves or other obvious corrosion indicators. We present a characterization scheme to delineate the contribution of OER and alloy dissolution, using scanning electrochemical microscopy (SECM) for OER-onset detection, and quantitative chemical analysis with inductively coupled-mass spectrometry (ICP-MS) and ultraviolet visible light (UV-Vis) spectroscopy to elucidate metal dissolution processes. In-situ electrochemical atomic force microscopy (EC-AFM) revealed that the transpassive metal dissolution on CrCoNi is dominated by intergranular corrosion. These results have significant implications for the stability of MPEAs in corrosion systems, emphasizing the necessity of analytically determining metal ions released from MPEA electrodes into the electrolyte when evaluating Faradaic efficiencies of OER catalysts. The release of transition metal ions not only reduces the Faradaic efficiency of electrolyzers but may also cause poisoning and degradation of membranes in electrochemical reactors.
N2 - Multi-Hauptelement-Legierungen (MPEAs) gewinnen in der Korrosions- und Elektrokatalyseforschung aufgrund ihrer elektrochemischen Stabilität über einen breiten pH-Bereich und der Vielfalt der möglichen chemischen Zusammensetzungen zunehmend an Interesse. In unseren Untersuchungen mit der äquimolaren CrCoNi-Legierung in einem sauren Elektrolyten (0.1 M NaCl, pH 2) beobachteten wir eine signifikante Metallauflösung, die mit der Sauerstoffentwicklungsreaktion (OER) im transpassiven Bereich einhergeht, obwohl in zyklischen Polarisationskurven keine Hysterese auftrat oder andere offensichtliche Korrosionsindikatoren vorlagen. In diesem Artikel wird ein Charakterisierungskonzept eingeführt, dass die Beiträge der OER und der Legierungsauflösung differenziert. Hierfür kommt die elektrochemische Rastermikroskopie (SECM) zum Nachweis des Beginns der OER und die quantitative chemische Analyse mit induktiv gekoppelter Massenspektrometrie (ICP-MS) und UV/Vis-Spektrometrie zur Aufklärung der Metallauflösungsprozesse zum Einsatz. Die elektrochemische In situ-Atomkraftmikroskopie (EC-AFM) zeigte, dass die intergranulare Korrosion der dominierende Mechanismus der transpassive Metallauflösung von CrCoNi ist. Diese Ergebnisse besitzen erhebliche Auswirkungen für die Beurteilung der Stabilität von MPEAs in Korrosionssystemen und der Stromausbeute von OER-Katalysatoren auf der Basis von MPEAs. Die Daten unterstreichen die Notwendigkeit der analytischen Bestimmung von Metallionen, die von MPEA-Elektroden freigesetzt werden. Die Freisetzung von Übergangsmetallionen verringert nicht nur die Stromausbeute von Elektrolyseuren, sondern kann zu einer Schädigung von Membranen in elektrochemischen Reaktoren führen.
KW - Transpassive dissolution
KW - Corrosion
KW - Multi-prinicpal element alloys (MPEAs)
KW - Passivation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597045
DO - https://doi.org/10.1002/anie.202317058
SP - 1
EP - 8
PB - Wiley VHC-Verlag
AN - OPUS4-59704
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kleinbub, Sherin
A1 - Braymer, Joseph J
A1 - Pfeiffer, Friedhelm
A1 - Dyall-Smith, Mike
A1 - Spirgath, Kristin
A1 - Alfaro-Espinoza, Gabriela
A1 - Koerdt, Andrea
T1 - From Genes to Black Rust: Genomic insights into corrosive methanogens
N2 - Within the past ten years, genetic evidence has been increasing for the direct role that microbes play in microbiologically influenced corrosion (MIC), also known as biocorrosion or biodeterioration. One prominent example is the correlation between the corrosion of metal and the presence of genes encoding an extracellular [NiFe]-hydrogenase (MIC hydrogenase) in the methanogenic archaeon, Methanococcus maripaludis. In this study, DNA sequencing and bioinformatic analysis were used to classify the MIC hydrogenase as belonging to a core set of genes, the MIC core, found so far in Methanococci and Methanobacteria classes of methanogens. Genetic evidence is provided for the mobilization of the MIC core via multiple mechanisms, including a horizontal gene transfer event from Methanobacteria to Methanococci and a newly described MIC-transposon. A detailed comparison of M. maripaludis genomes further pointed to the relevance that cell wall modifications involving N-glycosylation of S-layer proteins and the MIC hydrogenase likely play in methanogen-induced MIC (Mi-MIC). Microscopic analysis of corrosive methanogens encoding the MIC core indicated that Methanobacterium-affiliated strain IM1 can form extensive biofilms on the surface of corrosion products whereas individual cells of M. maripaludis Mic1c10 were only found localized to crevices in the corrosion layer. An updated model of Mi-MIC involving two modes of action is presented, which predicts that the propensity of cells to adhere to iron surfaces directly influences the rate of corrosion due to the localization of the MIC hydrogenase at the metal-microbe interface.
KW - Biocorrosion
KW - Hydrogenases
KW - Metalloprotein
KW - Microbes
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649425
DO - https://doi.org/10.1093/femsmc/xtaf018
SN - 2633-6685
VL - 6
SP - 1
EP - 19
PB - Oxford University Press (OUP)
AN - OPUS4-64942
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sun, Yijuan
A1 - Pérez-Padilla, Víctor
A1 - Valderrey, Virginia
A1 - Bell, Jérémy
A1 - Gawlitza, Kornelia
A1 - Rurack, Knut
T1 - Ratiometric detection of perfluoroalkyl carboxylic acids using dual fluorescent nanoparticles and a miniaturised microfluidic platform
N2 - The widespread contamination of soil and water with perfluoroalkyl substances (PFAS) has caused considerable societal and scientific concern. Legislative measures and an increased need for remediation require effective on-site analytical methods for PFAS management. Here we report on the development of a green-fluorescent guanidine-BODIPY indicator monomer incorporated into a molecularly imprinted polymer (MIP) for the selective detection of perfluorooctanoic acid (PFOA). Complexation of PFOA by the indicator, which is mediated by concerted protonation-induced ion pairing-assisted hydrogen bonding, significantly enhances fluorescence in polar organic solvents. The MIP forms as a thin layer on silica nanoparticles doped with tris(bipyridine)ruthenium(II) chloride, which provides an orange emission signal as internal reference, resulting in low measurement uncertainties. Using a liquid-liquid extraction protocol, this assay enables the direct detection of PFOA in environmental water samples and achieves a detection limit of 0.11 µM. Integration into an opto-microfluidic system enables a compact and user-friendly system for detecting PFOA in less than 15 minutes.
KW - PFAS
KW - Molecular imprinting
KW - Microfluidics
KW - Fluorescence
KW - Onsite assay
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650270
DO - https://doi.org/10.1038/s41467-025-66872-9
SN - 2041-1723
VL - 16
IS - 1
SP - 1
EP - 16
PB - Springer Science and Business Media LLC
AN - OPUS4-65027
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Oskoei, Párástu
A1 - Afonso, Rúben
A1 - Bastos, Verónica
A1 - Nogueira, João
A1 - Keller, Lisa-Marie
A1 - Andresen, Elina
A1 - Saleh, Maysoon I.
A1 - Rühle, Bastian
A1 - Resch-Genger, Ute
A1 - Daniel-da-Silva, Ana L.
A1 - Oliveira, Helena
T1 - Upconversion Nanoparticles with Mesoporous Silica Coatings for Doxorubicin Targeted Delivery to Melanoma Cells
N2 - Melanoma is one of the most aggressive skin cancers and requires innovative therapeutic strategies to overcome the limitations of conventional therapies. In this work, upconversion nanoparticles coated with mesoporous silica and functionalized with folic acid (UCNP@mSiO2-FA) were developed as a targeted nanocarrier system for the delivery of doxorubicin (DOX). The UCNPs were synthesized via thermal decomposition, coated with mesoporous silica shells, and functionalized with folic acid (FA) to enable receptor-mediated targeting. DOX was then loaded into the mesoporous silica coating by adsorption, yielding UCNP@mSiO2-FA-DOX. The different UCNPs were characterized for size, composition, colloidal stability, and loading and release of DOX. This comprehensive physicochemical characterization confirmed a high DOX loading efficiency and a slightly increased drug release under acidic conditions, mimicking the tumour microenvironment. In vitro assays using four melanoma cell lines (A375, B16-F10, MNT-1, and SK-MEL-28) revealed an excellent biocompatibility of UCNP@mSiO2-FA and a significantly higher cytotoxicity of UCNP@mSiO2-FA-DOX compared to unloaded UCNPs, in a dose-dependent manner. Cell cycle analysis demonstrated G2/M phase arrest after treatment with UCNP@mSiO2-FA-DOX, confirming its antiproliferative effect. Overall, UCNP@mSiO2-FA-DOX represents a promising nanoplatform for targeted melanoma therapy, combining active tumour targeting and enhanced anticancer efficacy.
KW - Fluorescence
KW - Synthesis
KW - Nano
KW - Particle
KW - Silica
KW - Cell
KW - Uptake
KW - Drug
KW - Characterization
KW - DOX
KW - Imaging
KW - Toxicity
KW - Release
KW - pH
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653596
DO - https://doi.org/10.3390/molecules31010074
SN - 1420-3049
VL - 31
IS - 1
SP - 1
EP - 18
PB - MDPI AG
AN - OPUS4-65359
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rodriguez, Santiago
A1 - Kumanski, Sylvain
A1 - Ayed, Zeineb
A1 - Fournet, Aurélie
A1 - Bouanchaud, Charlène
A1 - Sagar, Amin
A1 - Allemand, Frédéric
A1 - Baulin, Vladimir A.
A1 - Resch‐Genger, Ute
A1 - Cortés, Juan
A1 - Sibille, Nathalie
A1 - Chirot, Fabien
A1 - Wegner, Karl David
A1 - Antoine, Rodolphe
A1 - Le Guével, Xavier
A1 - Bernadó, Pau
T1 - Programming the Optoelectronic Properties of Atomically Precise Gold Nanoclusters Using the Conformational Landscape of Intrinsically Disordered Proteins
N2 - The rational design of hybrid nanomaterials with precisely controlled properties remains a central challenge in materials science. While atomically precise gold nanoclusters (Au‐NCs) offer molecule‐like control over a metallic core, tuning their optoelectronic behavior via surface engineering is often empirically driven. Here, we establish a design principle by demonstrating that the conformational landscape of intrinsically disordered proteins (IDP) can be used as a programmable scaffold to rationally modulate the photophysical properties of a covalently bound Au‐NC. We synthesized a series of bioconjugates between Au 25 nanoclusters and bioengineered IDPs containing a variable number of cysteine anchoring points. A combination of mass spectrometry, small‐angle X‐ray scattering, and modeling on the conjugates indicates that increasing the number of covalent anchors systematically restricts the conformational ensemble, inducing a progressively more compact protein shell around nanoclusters. This structural rigidification at the interface directly translates into a 15‐fold enhancement of the Au‐NC near‐infrared photoluminescence and a six‐fold increase in its average lifetime. Our findings demonstrate that the conformational plasticity of IDPs and the capacity to engineer them can be harnessed as a molecular tuning knob, moving to a new regime of programmable soft‐matter control over the properties of quantum‐confined nanomaterials for tailored biotechnological applications.
KW - Fluorescence
KW - Custer
KW - Nano
KW - Advanced material
KW - Characterization
KW - Fluorescence quantum yield
KW - Integrating sphere spectroscopy
KW - Thiol ligands
KW - Gold
KW - Surface chemistry
KW - SWIR
KW - Mass spectrometry
KW - Protein
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655086
DO - https://doi.org/10.1002/chem.202502991
SN - 0947-6539
SP - 1
EP - 9
PB - Wiley VHC-Verlag
AN - OPUS4-65508
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ahmed, A. A. A.
A1 - Alegret, N.
A1 - Almeida, B.
A1 - Alvarez-Puebla, R.
A1 - Andrews, A. M.
A1 - Ballerini, L.
A1 - Barrios-Capuchino, J. J.
A1 - Becker, C.
A1 - Blick, R. H.
A1 - Bonakdar, S.
A1 - Chakraborty, I.
A1 - Chen, X.
A1 - Cheon, J.
A1 - Chilla, G.
A1 - Conceicao, A. L. C.
A1 - Delehanty, J.
A1 - Dulle, M.
A1 - Efros, A. L.
A1 - Epple, M.
A1 - Fedyk, M.
A1 - Feliu, N.
A1 - Feng, M.
A1 - Fernandez-Chacon, R.
A1 - Fernandez-Cuesta, I.
A1 - Fertig, N.
A1 - Förster, S.
A1 - Garrido, J. A.
A1 - George, M.
A1 - Guse, A. H.
A1 - Hampp, N.
A1 - Harberts, J.
A1 - Han, J.
A1 - Heekeren, H. R.
A1 - Hofmann, U. G.
A1 - Holzapfel, M.
A1 - Hosseinkazemi, H.
A1 - Huang, Y.
A1 - Huber, P.
A1 - Hyeon, T.
A1 - Ingebrandt, S.
A1 - Ienca, M.
A1 - Iske, A.
A1 - Kang, Y.
A1 - Kasieczka, G.
A1 - Kim, D.-H.
A1 - Kostarelos, K.
A1 - Lee, J.-H.
A1 - Lin, K.-W.
A1 - Liu, S.
A1 - Liu, X.
A1 - Liu, Y.
A1 - Lohr, C.
A1 - Mailänder, V.
A1 - Maffongelli, L.
A1 - Megahed, S.
A1 - Mews, A.
A1 - Mutas, M.
A1 - Nack, L.
A1 - Nakatsuka, N.
A1 - Oertner, T. G.
A1 - Offenhäusser, A.
A1 - Oheim, M.
A1 - Otange, B.
A1 - Otto, F.
A1 - Patrono, E.
A1 - Peng, B.
A1 - Picchiotti, A.
A1 - Pierini, F.
A1 - Pötter-Nerger, M.
A1 - Pozzi, M.
A1 - Pralle, A.
A1 - Prato, M.
A1 - Qi, B.
A1 - Ramos-Cabrer, P.
A1 - Resch-Genger, Ute
A1 - Ritter, N.
A1 - Rittner, M.
A1 - Roy, S.
A1 - Santoro, F.
A1 - Schuck, N. W.
A1 - Schulz, F.
A1 - Seker, E.
A1 - Skiba, M.
A1 - Sosniok, M.
A1 - Stephan, H.
A1 - Wang, R.
A1 - Wang, T.
A1 - Wegner, Karl David
A1 - Weiss, P. S.
A1 - Xu, M.
A1 - Yang, C.
A1 - Zargarin, S. S.
A1 - Zeng, Y.
A1 - Zhou, Y.
A1 - Zhu, D.
A1 - Zierold, R.
A1 - Parak, W. J.
T1 - Interfacing with the Brain: How Nanotechnology Can Contribute
N2 - Interfacing artificial devices with the human brain is the central goal of neurotechnology. Yet, our imaginations are often limited by currently available paradigms and technologies. Suggestions for brain−machine interfaces have changed over time, along with the available technology.
Mechanical levers and cable winches were used to move parts of the brain during the mechanical age. Sophisticated electronic wiring and remote control have arisen during the electronic age, ultimately leading to plug-and-play computer interfaces. Nonetheless, our brains are so complex that these visions, until recently, largely remained unreachable dreams. The general problem, thus far, is that most of our technology is mechanically and/or electrically engineered, whereas the brain is a living, dynamic entity. As a result, these worlds are difficult to interface with one another. Nanotechnology, which encompasses engineered solid-state objects and integrated circuits, excels at small length scales of single to a few hundred nanometers and, thus, matches the sizes of biomolecules, biomolecular assemblies, and parts of cells. Consequently, we envision nanomaterials and nanotools as opportunities to interface with the brain in alternative ways. Here, we review the existing literature on the use of nanotechnology in brain−machine interfaces and look forward in discussing perspectives and limitations based on the authors’ expertise across a range of complementary disciplines from neuroscience, engineering, physics, and chemistry to biology and medicine, computer science and mathematics, and social science and jurisprudence. We focus on nanotechnology but also include information from related fields when useful and complementary.
KW - Nanoneuro interface
KW - Brain-on-a-chip
KW - Nanostructured interface
KW - Electrode arrays
KW - Neuro-implants
KW - Advanced nanomaterials
KW - Quality assurance
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634893
DO - https://doi.org/10.1021/acsnano.4c10525
SN - 1936-086X
VL - 19
IS - 11
SP - 10630
EP - 10717
PB - ACS Publications
AN - OPUS4-63489
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - El-Dahshan, O.
A1 - Deniaud, A.
A1 - Ling, W. L.
A1 - Wegner, Karl David
A1 - Proux, O.
A1 - Veronesi, G.
A1 - Reiss, P.
T1 - Hydrothermal microwave synthesis of water soluble NIR-II emitting Ag2S quantum dots
N2 - Hydrothermal-based synthetic methods of quantum dots allow for the exploration of reaction parameters normally inaccessible to typical aqueous-based batch reactions, such as elevated reaction temperatures (>100 °C) and reaction pressures above atmospheric pressure. Coupled with microwave heating, new instantaneously bio-compatible quantum dots (QDs) with enhanced opitcal properties can be yielded. As of today, aqueous-based synthetic methods often lag behind their organic analogues in terms of the photophysical properties of the QDs obtained and the ease of modulation of both the emission wavelength and crystallite size. Using a novel microwave-assisted hydrothermal approach, the synthesis of silver sulphide (Ag2S) QDs exhibiting NIR emission spanning the biological transparency windows via modulation of the reaction parameters has been developed. The intrinsic link between their optical and structural properties is explored via laboratory and synchrotron-based structural analysis techniques. Their toxicity towards a hepatic cell line was assessed, and related back to their structure and size. Overall this work aims to not only further develop the repertoire of synthetic methods for the synthesis of Ag2S QDs, but also paves the way for the development of safer QDs suitable for future clinical applications.
KW - Quantum dots
KW - Microwave synthesis
KW - Quality assurance
KW - NIR-II emission
KW - PL quantum yield
KW - Ag2S
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634825
DO - https://doi.org/10.1039/d5nr00052a
SN - 2040-3372
VL - 17
IS - 24
SP - 14637
EP - 14646
PB - RSC
AN - OPUS4-63482
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yu, Jialu
A1 - Oelze, Marcus
A1 - Schannor, Mathias
A1 - Nordstad, Simon
A1 - Vogl, Jochen
T1 - New Potential Haematite and Magnetite Reference Materials for Iron Isotope Measurements by Solution Nebulisation MC ‐ ICP ‐ MS and by In Situ ns ‐ LA ‐ MC ‐ ICP ‐ MS
N2 - Iron isotope ratios of haematite (Fe2O3) and magnetite (Fe3O4) provide insights into geochemical, environmental and planetary processes. In most studies, Fe isotope measurements are commonly performed using solution nebulisation multi-collector inductively coupled plasma-mass spectrometry (SN-MC-ICP-MS). Nanosecond laser ablation multi-collector inductively coupled plasma-mass spectrometry (ns-LA-MC-ICP-MS) requires minimal sample preparation, and provides spatially resolved variation of iron isotopes at micro-scale. However, homogeneous and matrix-matched haematite/magnetite reference materials are lacking for precise in situ isotopic measurement. The iron isotope ratios of two potential reference materials resembling natural haematite (HMIE-NP-B01) and natural magnetite (MAKP-NP-B01) were characterised. Size fractions between 5–63 μm of the powdered Fe oxides were milled to nanoparticles, freeze-dried, homogenised, and pressed into pellets. The materials were then evaluated using SN-MC-ICP-MS and LA-MC-ICP-MS. Sample powders of the two materials were measured by SN-MC-ICPMS after sample digestion and column separation and pressed pellets were analysed directly via ns-LA-MC-ICP-MS. In both cases iron isotope delta values are reported relative to the certified reference material IRMM-014, used as the bracketing standard (calibrator). The solution measurements yielded δ56Fe values of -0.25 ± 0.08‰ (N = 13, 2s) for HMIE-NP-B01, and -0.05 ± 0.09‰ (N = 12, 2s) for MAKP-NP-B01, considered as the preferred Fe isotope delta values. In situ isotopic analysis via ns-LA-MC-ICP-MS yielded δ56Fe values of -0.28 ± 0.28‰ (N = 19, 2s) for HMIE-NP-B01 and -0.12 ± 0.24‰ (N = 22, 2s) for MAKP-NP-B01, consistent with the solution Fe isotope data. The homogeneity of Fe isotopes of the pellets was evaluated by ns-LA-MC-ICP-MS analyses of three different positions to further confirm that both materials are isotopically homogeneous. Both materials can be considered as potential quality control and bracketing reference materials for Fe isotopic measurements by in situ ns-LA-MC-ICP-MS analysis.
KW - Laser ablation
KW - Fe isotope
KW - Fe-oxides
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654755
DO - https://doi.org/10.1111/ggr.70037
SN - 1639-4488
SP - 1
EP - 12
PB - John Wiley & Sons Ltd.
AN - OPUS4-65475
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Andresen, Elina
A1 - Islam, Fahima
A1 - Prinz, Carsten
A1 - Gehrmann, P.
A1 - Licha, K.
A1 - Roik, Janina
A1 - Recknagel, Sebastian
A1 - Resch-Genger, Ute
T1 - Assessing the reproducibility and up‑scaling of the synthesis of Er,Yb‑doped NaYF4‑based upconverting nanoparticles and control of size, morphology, and optical properties
N2 - Lanthanide-based, spectrally shifting, and multi-color luminescent upconverting nanoparticles (UCNPs) have received much attention in the last decades because of their applicability as reporter for bioimaging, super-resolution microscopy, and sensing as well as barcoding and anti-counterfeiting tags. A prerequisite for the broad application of UCNPs in areas such as sensing and encoding are simple, robust, and easily upscalable synthesis protocols that yield large quantities of UCNPs with sizes of 20 nm or more with precisely controlled and tunable physicochemical properties from lowcost reagents with a high reproducibility. In this context, we studied the reproducibility, robustness, and upscalability of the synthesis of β-NaYF4:Yb, Er UCNPs via thermal decomposition. Reaction parameters included solvent, precursor chemical compositions, ratio, and concentration. The resulting UCNPs were then examined regarding their application-relevant physicochemical properties such as size, size distribution, morphology, crystal phase, chemical composition, and photoluminescence.
Based on these screening studies, we propose a small volume and high-concentration synthesis approach that can provide UCNPs with different, yet controlled size, an excellent phase purity and tunable morphology in batch sizes of up to at least 5 g which are well suited for the fabrication of sensors, printable barcodes or authentication and recycling tags.
KW - Photoluminescence
KW - Nano
KW - Nanomaterial
KW - Synthesis
KW - Reproducibility
KW - Upconversion nanoparticle
KW - Lanthanide
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570170
DO - https://doi.org/10.1038/s41598-023-28875-8
SN - 2045-2322
VL - 13
IS - 1
SP - 1
EP - 13
AN - OPUS4-57017
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -