TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Ortel, Erik T1 - Inter-laboratory comparison on shape of bipyramidal TiO2 nanoparticles by TEM N2 - The TiO2 material selected for the present inter-laboratory comparison (ILC) was the bipyramidal anatase UT001 batch synthesized hydrothermally by University of Turin in the frame of the EU/FP7 Project SETNanoMetro and carefully prepared on TEM grids by BAM to be distributed to the ILC participants. A clear measurement protocol including data analysis and reporting (including an xls reporting template) has been also prepared by BAM. 14 of 18 participants have measured and reported results which have been already checked by BAM as being conform to the agreed protocol. After receiving the last results (of 4 participants) the ILC data evaluation will be carried out by BAM in line with agreed ISO/TC229 procedures as for the other case sudies. T2 - Annual Meeting of ISO/TC 229 Nanotechnologies CY - Singapore, Republic of Singapore DA - 07.11.2016 KW - TiO2 KW - Nanoparticles KW - Inter-laboratory comparison KW - Shape KW - TEM KW - Particle size distribution PY - 2016 AN - OPUS4-38868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rades, Steffi A1 - Ortel, Erik A1 - Wirth, Thomas A1 - Garcia, Sarai A1 - Gomez, Estibaliz A1 - Blanco, Miren A1 - Alberto, Gabriele A1 - Martra, Gianmario A1 - Hodoroaba, Vasile-Dan T1 - Analysis of functionalization of TiO2 nanoparticles and various substrates by means of SEM-EDX, AES and ToF-SIMS N2 - The physico-chemical characteristics of TiO2 coatings can greatly influence their final performance. In SETNanoMetro, different deposition procedures are being set for applying films of TiO2 NPs with defined and homogenous thickness on supports of interest for the applications studied in the project. The selected substrates are the following: (i) Silica glasses for photocatalytic measurements, (ii) Ti-alloys for orthopedic and/or dental prostheses, and for cell cultures, and (iii) Conductive glasses (e.g. Fluorine doped Tin Oxide, FTO) for dye-sensitized solar cells. From the different film deposition procedures studied within the project Self-assembly of TiO2 NPs in multiple layers was selected. For this, surface modification of the substrate and of TiO2 nanoparticles (NPs) with e.g. silane coupling agents is a prerequisite. First attempts to prepare the self-assembled coating on the functionalized glass substrates seem to indicate that the functionalized NPs adhere to the substrates, even if the final coatings were not homogenous and presented agglomerates. ToF-SIMS results support this outcome. In order to use the layer-by-layer deposition technique for the formation of TiO2 films by controlled self-assembly of the TiO2 NPs, the proper complementary moieties for the functionalization of the NPs were chosen. A first set of NPs has been produced by reaction with (3-aminopropyl)phosphonic acid (APPA) in order to functionalize the surface with free amino-groups. Then, the complementary NP set can be obtained from an aliquot of the first one, through the conversion of free surface amino-groups to aldehydes by reaction with glutaraldehyde. A proper approach for the functionalization of two types of TiO2, commercial P25 (Evonik) and SETNanoMetro-sample labelled UT001, with APPA was developed. A second set of NPs consisting of three types of TiO2 NPs, P25 and SETNanoMetro NPs (TiO2 NPs with high specific surface area > 150 m2/g and TiO2 NPs with low size < 20 nm) was functionalized with (3-aminopropyl)triethoxysilane (APTS). As for the previous set of NPs, the complementary NP set was obtained through the conversion of free surface amino-groups to aldehydes by reaction with glutaraldehyde. EDX, AES and ToF-SIMS spectra were collected and analyzed to demonstrate the presence of the surface functionalization of the different types of TiO2 NPs. T2 - Nanoscience meets Metrology - Synthesis, Characterization, Testing and Applications of Validated Nanoparticles - International Summer School CY - Turin, Italy DA - 04.09.2016 KW - Time-of-flight secondary-ion mass spectrometry KW - X-ray spectroscopy KW - Auger electron spectroscopy KW - Electron microscopy KW - Nanoparticles KW - Thin films PY - 2016 UR - http://www.setnanometro.eu/events/ AN - OPUS4-38064 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Natte, Kishore A1 - Friedrich, Jörg Florian A1 - Wohlrab, Sebastian A1 - Lutzki, J. A1 - von Klitzing, R. A1 - Österle, Werner A1 - Orts-Gil, Guillermo T1 - Impact of polymer shell on the formation and time evolution of nanoparticle-protein corona N2 - The study of protein corona formation on nanoparticles (NPs) represents an actual main issue in colloidal, biomedical and toxicological sciences. However, little is known about the influence of polymer shells on the formation and time evolution of protein corona onto functionalized NPs. Therefore, silicapoly(ethylene glycol) core–shell nanohybrids (SNPs@PEG) with different polymer molecular weights (MW) were synthesized and exhaustively characterized. Bovine serum albumin (BSA) at different concentrations (0.1–6 wt%) was used as model protein to study protein corona formation and time evolution. For pristine SNPs and SNPs@PEG (MW = 350 g/mol), zeta potential at different incubation times show a dynamical evolution of the nanoparticle–protein corona. Oppositely, for SNPs@PEG with MW ≥2000 g/mol a significant suppression of corona formation and time evolution was observed. Furthermore, AFM investigations suggest a different orientation (side-chain or perpendicular) and Penetration depth of BSA toward PEGylated surfaces depending on the polymer length which may explain differences in protein corona evolution. KW - Nanoparticles KW - Silica KW - PEGylation KW - Protein corona KW - BSA KW - Biointerface PY - 2013 DO - https://doi.org/10.1016/j.colsurfb.2012.11.019 SN - 0927-7765 VL - 104 SP - 213 EP - 220 PB - Elsevier AN - OPUS4-38547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mielke, Johannes A1 - Dohányosová, P. A1 - Lopez, S. A1 - Hodoroaba, Vasile-Dan T1 - Electrospray deposition of nanoparticles on TEM grids N2 - The authors have tested the prototype of an electrospray deposition system developed by the company RAMEM under its trademark IONER. To test the prototype and assess its performance, several materials have been sprayed onto TEM grids and the resulting particle distributions were compared to more traditional sample preparation strategies like the “drop on grid” method. Operation parameters such as the sample flow-rate, capillary – substrate distance, electric field strength and sampling period length have been optimized. It was found that the particles deposited by electrospray generally show a much more homogeneous spatial distribution on the substrate and a substantial increase of the number of single particles, which are much better suited to an automatic image evaluation procedure than the agglomerated particles observed otherwise. The applicability of the technique to a broad range of materials is demonstrated by various examples, but also the influence of the substrate, the choice of the particular TEM grid, on the obtained spatial particle distribution is assessed. KW - Electrspray deposition KW - Electron microscopy KW - Nanoparticles KW - Sample preparation PY - 2016 UR - https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/electrospray-deposition-of-nanoparticles-on-tem-grids/459E634B7F74D474A19E15E69DA82E5D DO - https://doi.org/10.1017/S1431927616010072 SN - 1431-9276 SN - 1435-8115 VL - 22 IS - Suppl 3 SP - 1846 EP - 1847 PB - Cambridge AN - OPUS4-38436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Iannarelli, L. A1 - Giovanozzi, A. M. A1 - Diomede, L. A1 - Morelli, F. A1 - Viscotti, F. A1 - Maurino, V. A1 - Bigini, P. A1 - Martra, G. A1 - Spoto, G. A1 - Ortel, Erik A1 - Hodoroaba, Vasile-Dan A1 - Rossi, A. M. T1 - Shape engineered TiO2 nanoparticles in Caenorhabditis elegans: a Raman imaging based approach to assist tissue-specific toxicological studies N2 - In vivo detailed spatial distribution of TiO2 NPs was here investigated for the first time using a 2D chemical imaging analysis based on Confocal Raman Spectroscopy. The invertebrate nematode C. elegans was employed as prototypical model of living organism. Rod, bipyramidal and quasi-spherical engineered TiO2 NPs with different primary particle sizes and agglomeration states were prepared, characterized and then administered to nematodes. Exploiting the typical fingerprint of TiO2 in the Raman spectrum, we monitored the biodistribution of NPs inside the worm using a non-invasive, label-free method. The high spatial resolution chemical imaging and the specificity of the Raman technique in the localization of TiO2 NPs helped in the design of behavioral C. elegans studies aimed at elucidating the relationship among the size, shape, and agglomeration state of NPs and their ability to induce specific toxic effects. T2 - 16th European Conference on Applications of Surface and Interface Analysis ECASIA'15 CY - Fortaleza, Brazil DA - 14.08.2016 KW - TiO2 KW - Nanoparticles KW - Raman imaging KW - Toxicological studies PY - 2016 AN - OPUS4-38240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thünemann, Andreas A1 - Kästner, Claudia T1 - (Bio)polymers tune the catalytic activity of silver nanoparticles N2 - We report on the development of ultra-small core-shell silver nanoparticles synthesized by an up-scaled modification of the polyol process. It is foreseen to use these thoroughly characterized particles as reference material to compare the catalytic and biological properties of functionalized silver nanoparticles. Small-angle X-ray scattering (SAXS) analysis reveal a narrow size distribution of the silver cores with a mean radius of RC = 3.0 nm and a distribution width of 0.6 nm. Dynamic light scattering (DLS) provides a hydrodynamic radius of RH = 10.0 nm and a PDI of 0.09. The particles’ surface is covered with poly(acrylic acid) (PAA) forming a shell with a thickness of 7.0 nm, which provides colloidal stability lasting for more than six months at ambient conditions. The PAA can be easily exchanged by biomolecules to modify the surface functionality. Replacements of PAA with glutathione (GSH) and bovine serum albumin (BSA) have been performed as examples. We demonstrate that the particles effectively catalyze the reduction of 4-nitrophenol to 4-aminophenol with sodium borohydride. The tunable catalytic activity of (436 ± 24) L g-1 s-1 is the highest reported in literature for silver nanoparticles. T2 - POLYDAYS 2016 CY - Potsdam, Germany DA - 28.09.2016 KW - Nanoparticles KW - Small-angle X-ray scattering KW - SAXS KW - Silver PY - 2016 AN - OPUS4-37622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Nanoparticles and films characterization: Electron microscopy and related techniques N2 - Scanning Electron Microscopy (SEM) represents the mostly widespread method available in analytical laboratories dedicated to the characterization of physical properties such as morphology of various solid materials from ‘micro-’ down to the nanometre scale. The use of secondary electrons excited by a sharply, nm-focussed primary electron beam enables at any modern SEM to image objects with high in-depth and lateral sensitivity, i.e. with high spatial resolution. Hence, e. g. nanoparticles (NPs) are able to be easily characterized with respect to their individual size and shape, but also to the morphology of their surface. By preparing the nano-objects on thin membranes as electron transparent samples it is possible to perform electron microscopy in the transmission mode (TEM and TSEM). The corresponding transmission (i.e. mass-thickness) contrast reveals in-depth information, but is also well suited for dimensional measurements in the 2D projection image. Both the surface sensitive mode and the transmission one are meanwhile available at any modern SEM. If an X-ray spectrometer is attached to an electron microscope, it is possible to analyse the characteristic X-rays induced by electron bombardment. Most electron microscopes have attached an energy dispersive X-ray spectrometer (EDX) so that EDX elemental maps can be carried out. Recent technological developments of high throughput EDS detectors and their advantages regarding high-resolution X-ray analysis down to the nm range are reviewed. High-resolution micrographs (SEM, TSEM, TEM) and corresponding X-ray elemental maps on various representative nanoparticles, but also layered samples prepared in cross-section, will be presented and discussed. The importance of selecting the best suited analysis conditions will be highlighted. Also other, often challenging, topics such as sample preparation and image data processing will be critically addressed by practical examples. Further analytical techniques able to be employed at an electron microscope, like cathodoluminescence (CL) or micro-X-ray fluorescence (µXRF) will be briefly surveyed. T2 - Nanoscience Meets Metrology - Synthesis, Characterization, Testing and Applications of Validated Nanoparticles - International Summer School CY - Turin, Italy DA - 04.09.2016 KW - Nanoparticles KW - Electron microscopy KW - High-resolution KW - Thin films KW - X-ray spectroscopy PY - 2016 UR - http://www.setnanometro.eu/events/ AN - OPUS4-37325 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Traub, Heike A1 - Drescher, Daniela A1 - Büchner, T. A1 - Zeise, Ingrid A1 - Kneipp, Janina A1 - Jakubowski, Norbert T1 - Studying cellular uptake and processing of nanoparticles by LA-ICP-MS N2 - In recent years, elemental imaging of biological samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is gaining in importance. Latest improvements regarding spatial resolution (down to 1 µm) and washout time make LA-ICP-MS particularly interesting for single cell analysis. Many current nanomaterials can serve as contrast agents in cellular or tissue imaging, drug delivery vehicles or therapeutics, whereas others can cause toxic effects. In order to evaluate nano-bio interactions, the number of nanoparticles (NPs) inside cells as well as their localisation within cellular substructures is of particular interest. LA-ICP-MS was used to study the NP pathway from uptake, via intracellular processing up to cell division. Fibroblast cells were incubated with different metallic NPs under varying experimental conditions. For LA analysis the cells were fixed with formaldehyde and dried. Our results show that LA-ICP-MS is able to localise NP aggregates within cellular substructures. The NPs accumulate in the perinuclear region in the course of intracellular processing, e.g. multivesicular fusion and endosomal maturation, but do not enter the nucleus [1, 2]. A strong dependence of NP uptake on concentration and incubation time was found. Additionally, the number of NPs internalized by individual cells was determined and variations within the cell population became visible. A new laser ablation system providing a short washout time (50 ms) together with small spot sizes (< 4 µm) and high repetition rates allows high spatial resolution applications. First results of cell imaging will be shown. The findings demonstrate the potential of LA-ICP-MS enabling insight into NP uptake and intracellular distribution dependent on experimental parameters. T2 - 8th Nordic Conference on Plasma Spectrochemistry CY - Loen, Norway DA - 05.06.2016 KW - Imaging KW - LA-ICP-MS KW - Cell KW - Nanoparticles PY - 2016 AN - OPUS4-36500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sötebier, Carina A1 - Bierkandt, Frank A1 - Bettmer, J. A1 - Rades, Steffi A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Weidner, Steffen T1 - Characterization of Ag nanoparticles: limitation and advantages of field-flow fractionation N2 - Silver nanoparticles (Ag NPs) are widely used in consumer products due to their excellent antibacterial properties. Their broad application has led to a variety of recent regulation on their use and labelling. Thus, a highly specific analytical method for their characterization and quantification is needed. Due to their large separation range, field-flow fractionation (FFF) techniques are repeatedly applied for the analysis of NP. Limitations of FFF include quantification, sample loss and insufficient recovery rates. Another challenge can be non-ideal elution behavior of particles in complex and unknown matrices. The possible sources for sample losses of Ag NP have been studied using an asymmetric flow FFF (AF4) in combination with inductively coupled plasma mass spectrometry (ICP-MS). The influence of different parameters, for example the sample concentration, on the recovery rates and sample loss has been investigated. Using laser ablation ICP-MS, the Ag deposition on the membrane was located and quantified. Our results identified ionic silver as the main sources of sample loss. These results can be useful for further method improvement. However, when a Ag NP sample containing an unknown complex matrix is analyzed, FFF method optimization is challenging as the sample might show a shift in the retention times and lower recovery rates. In this case, ICP-MS experiment in the single particle mode (sp-ICP-MS) can be a useful addition to the FFF measurement. Here, upon assumption of spherical particles, the geometric diameters can be calculated. This fast and easy approach can be helpful in order to interpret the FFF fractograms and advice the FFF method optimization process. T2 - 18th International Symposium on Field- and Flow-Based Separations CY - Dresden, Germany DA - 22.05.2016 KW - Silver KW - Nanoparticles KW - Field-flow fractionation KW - ICP-MS PY - 2016 AN - OPUS4-36352 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sieg, H. A1 - Krause, B. A1 - Lichtenstein, D. A1 - Böhmert, L. A1 - Kästner, Claudia A1 - Hansen, Ulf A1 - Tentschert, J. A1 - Laux, P. A1 - Braeuning, A. A1 - Thünemann, Andreas A1 - Luch, A. A1 - Lampen, A. T1 - Artificial digestion of aluminium-containing nanomaterials and their effects on the gastrointestinal tract in vitro N2 - Although aluminium is one of the most common elements in the biosphere, up to now little is known about its impact on human health. aluminium and its chemical derivatives are highly abundant in food, food contact materials and consumer products. Humans are exposed to aluminium via the gastrointestinal tract (GI tract). Exposition can change substantially due to consumer behavior since aluminium is also a compound of numerous food additives. Recently, aluminium exposition is increasingly considered to cohere with cancer and neurodegenerative disorders. Lately, due to an increasing attentiveness on this topic, limiting values for food additives have been tightened by the EFSA. However, cellular effects of aluminium and especially aluminium-containing nanomaterials, that represent a significant part of chemicals found in food products, are widely unknown and in the focus of our research activities, for example in the bilateral SolNanoTOX project. We established an in vitro simulation system of the GI tract, where nanomaterials undergo the different physiological, chemical and proteinbiochemical conditions of saliva, gastric juice and the intestine. The artificially digested nanomaterials, as well as soluble aluminium chloride as ionic control substance, were subjected to several analytical and biochemical methods to characterize their change of appearance and their cytotoxic effects on intestinal cellular models. We observed the fate of the nanomaterials during typical pH-values of saliva, gastric and intestinal juice with Dynamic light scattering measurements and ICP-MS in the single particle mode. After observable disappearance at pH 2 the particles recovered in the simulated intestinal fluid. The simulation of the GI tract, mainly the change of pH settings, can lead to a certain chemical activation of aluminium that can increase bioavailability in the intestine after oral uptake of aluminium-containing food products. In vitro assays like CTB, MTT and cellular impedance measurements showed that there were no acute cytotoxic effects measurable after a period up to 48h after incubation, comparable to undigested particles. In contrast, high amounts of aluminium ions showed synergistic effects on cell viability compared to non-digested aluminium ions. Although toxicological potential of Al ions to healthy tissue appears to be low, increased hazardous potential cannot be ruled out to pre-damaged tissue and can have a relevance in risk assessment for special consumer groups with for example chronical intestinal inflammation or dietary eating behavior combined with high exposure to Al-containing food products. T2 - 82nd Annual Meeting of the German Society for Experimental and Clinical Pharmacology and Toxicology CY - Berlin, Germany DA - 29.02.2016 KW - Nanoparticles KW - Digestion KW - SAXS KW - Cytotoxicity PY - 2016 AN - OPUS4-36026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Harald T1 - Core-shell systems - different cases N2 - Coating, stabilization layers, functionalization of particles or simple contamination are common variants of a core-shell system. For smaller nanoparticles this is of major importance. A particle with 16 nm diameter and a usual surface layer of 2 nm will have the same volume for the core as for the shell. In this case the material of the particle doesn’t have a clear definition. It is a common case that a particle consists of four different layers: Core, shell, stabilization layer and contamination. The properties of the particles differ according to this structure. For example silver particles might have a different dissolution rate for pure particles and for particles which are grown on top of a core. Different solubility or defined other properties of materials is a common reason for producing core-shell systems. Gold cores are surrounded by silica to stabilize them or to get a defined distance between the cores. Silica might be surrounded by gold and the silica dissolved afterwards. This delivers hollow shells. Another important example for core-shell systems are quantum dots. A small core is surrounded by a different material for increasing the photoluminescence. Furthermore there a stabilization layer is needed. The smallest part of the final particles is the initial core. The photoluminescence is based on this core, but the shells contain much more material. Categorization should address this. Core-shell systems are not covered by most of the existing decision trees for grouping. They are either regarded as special case or a singular layer. This disqualifies core-shell systems for grouping within the common models. There might be a very easy way to avoid this problem and even to combine some of the different decision trees. Starting the decision tree with the solubility of the outer shell and subsequently addressing the inner layers will be a pragmatic approach to solve the problem. If there is no shell, the categorization can start with a tiered approach or with the proposed “stawman” chemical categorization. If a shell is covering the surface there is a need to check if the shell is stable. If it is stable, the particle can be categorized based on this shell. If it is soluble, the ions need to be addressed as in the classic case. Furthermore the shell might increase the uptake by the cells. If the ions and the uptake are not critical the categorization can continue with the next layer. With this not perfect but pragmatic approach, the surface layers can be addressed with very limited additional efforts. Most criteria are based on classically tabulated data. Including a rating system like the precautionary matrix approach might even address the fact that some parameters are not always Yes/No, e.g. solubility, ion toxicity and uptake. T2 - OECD Expert Meeting on Grouping and Read Across for the Hazard Assessment of Manufactured Nanomaterials CY - Brussels, Belgium DA - 13.04.2016 KW - OECD KW - Nanoparticles KW - Nanomaterials KW - Grouping KW - Nano PY - 2016 AN - OPUS4-35774 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bantz, C. A1 - Koshkina, Olga A1 - Lang, Thomas A1 - Galla, H.-J. A1 - Kirkpatrick, C.J. A1 - Stauber, R.H. A1 - Maskos, M. T1 - The surface properties of nanoparticles determine the agglomeration state and the size of the particles under physiological conditions N2 - Due to the recent widespread application of nanomaterials to biological systems, a careful consideration of their physiological impact is required. This demands an understanding of the complex processes at the bio–nano interface. Therefore, a comprehensive and accurate characterization of the material under physiological conditions is crucial to correlate the observed biological impact with defined colloidal properties. As promising candidates for biomedical applications, two SiO2-based nanomaterial systems were chosen for extensive size characterization to investigate the agglomeration behavior under physiological conditions. To combine the benefits of different characterization techniques and to compensate for their respective drawbacks, transmission electron microscopy, dynamic light scattering and asymmetric flow field-flow fractionation were applied. The investigated particle systems were (i) negatively charged silica particles and (ii) poly(organosiloxane) particles offering variable surface modification opportunities (positively charged, polymer coated). It is shown that the surface properties primarily determine the agglomeration state of the particles and therefore their effective size, especially under physiological conditions. Thus, the biological identity of a nanomaterial is clearly influenced by differentiating surface properties. KW - Nanomaterial characterization KW - Physiological conditions KW - Surface properties KW - Silica nanoparticles KW - Siloxane nanoparticles KW - Nanoparticles KW - Colloids KW - Silica KW - Polyorganosiloxane KW - Siloxane KW - Characterization KW - Transmission electron microscopy KW - TEM KW - Cryo-TEM KW - Asymetrical flow field-flow fractionation KW - AF-FFF KW - Field-flow fractionation KW - FFF KW - Dynamic light scattering KW - DLS KW - PCS PY - 2014 DO - https://doi.org/10.3762/bjnano.5.188 SN - 2190-4286 VL - 5 SP - 1774 EP - 1786 CY - Frankfurt, M. AN - OPUS4-32575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Siebler, Daniel A1 - Lothongkam, Chaiyaporn A1 - Rohwetter, Philipp A1 - Habel, Wolfgang A1 - Heidmann, G. T1 - Fluorescent fiber optical partial discharge sensor in high-voltage cable facilities N2 - New sensors for the detection of partial discharges (PDs) in high-voltage (HV) cable accessories are being de-veloped consisting of a fluorescent polymer optical fiber (F-POF) as sensing element. Depending on the fiber material F-POFs can be attached to and even integrated into the translucent silicone rubber insulation of HV cable terminations. As the embedment into the insulation material plays an important role, the sensor should not weaken the dielectric strength of the insulation material and should not be the origin of PD incidents. A sensor consisting of a commercial F-POF has been tested in the high-voltage lab regarding its PD detection ability un-der AC in comparison to a conventional electrical sensor. New silicone rubber F-POF (Si-F-POF) fiber models functionalized with coumarin dyes have been produced. The optical properties of these dye functionalized silox-anes are presented. These potential sensor fibers are highly flexible and might be embeddable at medium to high-voltage level. An additional way to further improve the level of PD light detection is to modify the translucent type of silicone rubber used in HV cable accessories in terms of optical transparency. In this context we present our first results of the optical and mechanical properties of new elastomeric transparent silicone materials specif-ically designed for the application as HV insulation materials in stress cones. T2 - POF 2013 - 22nd International conference on plastic optical fibers CY - Búzios, Rio de Janeiro, Brazil DA - 11.09.2013 KW - Polymer optical fiber KW - Fluorescence sensor KW - Partial discharge monitoring KW - High-voltage power cable KW - Silicone rubber KW - Fluorescence dye KW - Nanoparticles PY - 2013 SP - 322 EP - 327 CY - Rio de Janeiro, Brazil AN - OPUS4-30266 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Natte, Kishore A1 - Orts Gil, Guillermo A1 - Unger, Wolfgang T1 - Morphology of nanoparticles - A characterization using high-resolution SEM N2 - Potential candidates of reference nano-materials are manufactured and systematically characterized in particular with respect to their morphology (shape, size and size distribution) in the frame of the running large European project NanoValid. By exploiting the transmission operation mode in a SEM, known as T-SEM, it is demonstrated by means of three representative examples of nanoparticles how a quick morphological inspection up to a complete, metrological characterization is feasible. KW - Nanoparticles KW - SEM KW - TEM KW - T-SEM KW - NanoValid PY - 2013 SN - 1439-4243 SN - 1863-7809 VL - 15 IS - 1 SP - 54 EP - 56 PB - GIT-Verl. CY - Darmstadt AN - OPUS4-27925 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koshkina, Olga A1 - Bantz, C. A1 - Würth, Christian A1 - Lang, Thomas A1 - Resch-Genger, Ute A1 - Maskos, Michael T1 - Fluorophore-labeled siloxane-based nanoparticles for biomedical applications N2 - We present the synthesis and characterization of multifunctional fluorophore-labeled poly(organosiloxane) nanoparticles with core-shell architecture, where the fluorescent dye is incorporated into the core. Grafting of heterobifunctional poly(ethylene oxide) (PEO) onto the particle surface leads to water-soluble biocompatible nanoparticles. Two different strategies have been used for the synthesis: The encapsulation of dye-labeled monomers during the polycondensation with additional PEO coating and subsequent dye labeling by covalent attachment of the fluorescent dye rhodamine B to the (chloromethylphenyl)siloxane groups in the core after polymerization and grafting of PEO onto the surface. Comparison of the fluorescence quantum yields of the nanoparticles before and after PEO coating show a decrease in quantum yield after PEO coating. KW - Biocompatibility KW - Core-shell KW - Fluorescence KW - Fluorescence quantum yield KW - Nanoparticles KW - PEO PY - 2011 DO - https://doi.org/10.1002/masy.201100041 SN - 1022-1360 SN - 0258-0322 SN - 1521-3900 VL - 309/310 IS - 1 SP - 141 EP - 146 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-25143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Behnke, Thomas A1 - Drescher, Daniela A1 - Kneipp, Janina A1 - Resch-Genger, Ute T1 - Lifetime-based discrimination between spectrally matching vis and NIR emitting particle labels and probes N2 - Increasing the information content from bioassays which requires robust and efficient strategies for the detection of multiple analytes or targets in a single measurement is an important field of research, especially in the context of meeting current security and health concerns. An attractive alternative to spectral multiplexing, which relies on fluorescent labels excitable at the same wavelength, yet sufficiently differing in their emission spectra or color presents lifetime multiplexing. For this purpose, we recently introduced a new strategy based on 'pattern-matching' in the lifetime domain, which was exemplary exploited for the discrimination between organic dyes and quantum dot labels revealing multi-exponential decay kinetics and allowed quantification of these labels. Meanwhile, we have succeeded in extending this lifetime multiplexing approach to nanometer-sized particle labels and probes absorbing and emitting in the visible (vis) and near-infrared (NIR) spectral region. Here, we present a first proof-of-principle of this approach for a pair of NIR-fluorescent particles. Each particle is loaded with a single organic dye chosen to display very similar absorption and emission spectra, yet different fluorescence decay kinetics. Examples for the lifetime-based distinction between pairs of these fluorescent nanoparticles in solution and in cells are presented. The results underline the potential of fluorescenc lifetime multiplexing in life science and bioanalysis. KW - Fluorescence KW - Fluorescence lifetime imaging microscopy KW - FLIM KW - Lifetime Multiplexing KW - Particle Label KW - Near-infrared KW - NIR KW - Cell imaging KW - Nanoparticles PY - 2011 DO - https://doi.org/10.1117/12.881442 SN - 1605-7422 VL - 7905 SP - 79051F-1 EP - 79051F-9 PB - SPIE, The International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-23637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Behnke, Thomas A1 - Brehm, Robert A1 - Grabolle, Markus A1 - Hennig, Andreas A1 - Hoffmann, Angelika A1 - Hoffmann, Katrin A1 - Linck, Lena A1 - Lochmann, Cornelia A1 - Pauli, Jutta A1 - Spieles, Monika A1 - Würth, Christian T1 - Funktionelle Chromophor-Systeme, innovative Validierungskonzepte und rückführbare Standards für die fluoreszenzbasierte multiparametrische Bioanalytik N2 - Unter dem Motto „Innovation und Qualitätssicherung in der (Bio)Analytik“ werden in der Arbeitsgruppe Fluoreszenzspektroskopie der BAM, Bundesanstalt für Materialforschung und -prüfung, funktionelle Chromophor-Systeme, einfache Signalverstärkungs- und Multiplexingstrategien sowie innovative Validierungs- und rückführbare Standardisierungskonzepte für verschiedene fluorometrische Messgrößen und Methoden entwickelt. Im Mittelpunkt stehen dabei molekulare Fluorophore, Nanokristalle mit größenabhängigen optischen Eigenschaften (sogenannte Quantenpunkte, QDs) und fluoreszierende Partikel variabler Größe sowie Sonden und Sensormoleküle für neutrale und ionische Analyte und für die Charakterisierung von funktionellen Gruppen. Dabei erfolgen auch methodische Entwicklungen für die Fluoreszenzspektroskopie, die Fluoreszenzmikroskopie, die Milcrofluorometrie, die Sensorik und die Mikroarraytechnologie. Ziele sind u. a. das Design und die Untersuchung von multiplexfähigen selektiven und sensitiven Sonden für die Biomarkeranalytik, die Entwicklung von Methoden zur Charakterisierung der signalrelevanten Eigenschaften dieser Chromophor-Systeme und zur Charakterisierung von funktionellen Gruppen an Oberflächen und ihre Validierung sowie die Entwicklung und Bereitstellung von formatadaptierbaren, flexibel ersetzbaren Standards für die fluoreszenzbasierte Multiparameteranalytik. T2 - 5. Senftenberger Innovationsforum Multiparameteranalytik CY - Senftenberg, Deutschland DA - 10.03.2011 KW - Multiparametric KW - Multiplexing KW - Fluorescence KW - Nanoparticles KW - NIR dyes KW - Surface analysis KW - Quantum yield KW - Quantum dot KW - Lifetime PY - 2011 SP - 86 EP - 108 CY - Senftenberg AN - OPUS4-23635 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Bresch, Harald A1 - Dörfel, Ilona A1 - Fink, C. A1 - Giese, A. A1 - Prietzel, Claudia A1 - Seeger, Stefan A1 - Walter, J. T1 - Examination of airborne brake dust T2 - JEF 2010 - 6th European conference on braking CY - Lille, France DA - 2010-11-24 KW - Brake dust KW - Nanoparticles KW - Size-distribution PY - 2010 SP - 1 EP - 6(?) AN - OPUS4-22655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Descalzo López, Ana Belén A1 - Zhu, Shengchao A1 - Fischer, Tobias A1 - Rurack, Knut ED - Demchenko, A.P. T1 - Optimization of the coupling of target recognition and signal generation N2 - Fluorescent reporters that literally "light up" upon binding of a target species are particularly interesting from an analytical point of view. This contribution introduces the main signaling concepts in fluorescent probe research, discusses strategies toward their optimization in terms of signal output, and highlights the wealth of alternative protocols that has been realized in the past two decades to create signaling systems with luminescence amplification features. KW - Dyes KW - Fluorescence KW - FRET KW - Molecular Recognition KW - Nanoparticles PY - 2010 SN - 978-3-642-04699-5 DO - https://doi.org/10.1007/978-3-642-04701-5_2 N1 - Serientitel: Springer Series on Fluorescence – Series title: Springer Series on Fluorescence VL - 9 IS - 1 SP - 41 EP - 106 PB - Springer AN - OPUS4-21941 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN ED - Boulmer-Leborgne, C. ED - Dinescu, G. ED - Krüger, Jörg ED - Orlando, S. ED - Habermeier, H.-U. T1 - Topical Issue: Laser and Plasma Processing for Advanced Materials / Journal of Optoelectronics and Advanced Materials, Vol. 12, No. 3, March 2010 N2 - Laser and plasma processing of materials is a rapidly growing field in fundamental science and materials technology requiring both a multidisciplinary approach and a wide-ranging knowledge. The topical issue “Laser and plasma processing for advanced materials” of the Journal of Optoelectronics and Advanced Materials covers a number of recent research highlights. The production of thin functionalized films, nanoparticles and nanocomposites using pulsed laser ablation (PLA) and deposition (PLD) or plasma treatment is discussed in a number of papers. Additionally, experiments using matrix assisted pulsed laser evaporation (MAPLE) are described. It is shown in this book that nanoparticles are generated and/or processed by laser or plasma interaction in very different environments ranging from gaseous and liquid to solid phase. Material properties change if the particle size is reduced below a critical limit allowing e.g. optical, electronic, biomedical, and environmental applications. Micro- and nanostructuring of surfaces (2D) and within the bulk of transparent materials (3D) is presented in various articles. In many cases, ultrashort laser pulses were applied. Furthermore, nanoparticles interacting with laser radiation can be used for nanostructuring purposes. Apart from experimental investigations, numerical modeling of the interaction of femtosecond laser pulses with materials has also been performed to understand structure formation theoretically. Especially for bio-functionalization, selective deposition of sensitive materials (e.g. proteins, cells) on surfaces is needed. A sophisticated process used for this purpose is known as laser induced forward transfer (LIFT). Recent findings regarding the LIFT method are depicted in this issue. Laser annealing of implanted dopants and thin films aiming to enhance structural and electrical properties, sensor dicing by laser radiation, and laser or plasma surface modification for the improvement of solar cells or polymer wettability change are but a few of the subjects focusing on applied research. Additionally, hybrid processes combining plasma spraying and laser-induced melting to control microstructure of coatings are introduced. Last but not least, achievements regarding analytical techniques are outlined. Laser induced breakdown spectroscopy (LIBS) make up a large part of this class. Additionally, the contributions to optical emission spectroscopy and mass spectrometry of plasma processes are significant. KW - Pulsed laser ablation KW - Evaporation KW - Deposition KW - Laser and plasma interaction KW - Laser micro- and nanostructuring KW - Nanoparticles KW - Laser induced forward transfer KW - Laser surface modifications KW - Plasma treatment PY - 2010 SN - 1454-4164 SP - 421 EP - 789 PB - INOE & INFM CY - Bucharest AN - OPUS4-21619 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -