TY - CONF A1 - Resch-Genger, Ute T1 - Advanced characterization of nanomaterials N2 - The rational synthesis and use of nanomaterials require the characterization of many different properties, ranging from particle size and size distribution over surface chemistry to more applicationrelevant features like optical, electrochemical, and magnetic properties. In the following, several methods for the characterization of functional groups on nanomaterials, like polymer and silica nanoparticles, semiconductor quantum dots, and lanthanide-based upconversion nanocrystals are presented. Additionally, procedures for the measurement of the key spectroscopic performance parameters of nanomaterials with linear and nonlinear photoluminescence, such as the photoluminescence quantum yield, are presented for the UV/vis/NIR/SWIR. T2 - Summerschool CY - Bad Honnef, Germany DA - 22.07.2019 KW - Quantum yield KW - Nanoparticle KW - Fluorescence KW - Quantum dot KW - NIR KW - SWIR KW - Quality assurance KW - Calibration PY - 2019 AN - OPUS4-48630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meierhofer, F. A1 - Dissinger, F. A1 - Weigert, Florian A1 - Resch-Genger, Ute A1 - Waldvogel, S. R. A1 - Voss, T. T1 - Citric-Acid-Based Carbon Dots with Luminescence Quantum Yields > 50%: spectral tuning of the luminescence by ligand exchange and pH adjustment N2 - We report the synthesis and characterization of carbon nanodots (CDs) with high quantum yield (>50%) and tailored optical absorption as well as emission properties. A well-described protocol with polyethyleneimine (PEI) as amine precursor is used as a reference to a new CD system which is stabilized by aromatic 2,3-diaminopyridine (DAP) molecules instead. The DAP stabilizer is installed in order to red-shift the absorption peak of the n-π* electron transition allowing efficient radiative recombination and light emission. Size, shape, and chemical composition of the samples are determined by (HR)TEM, EDX and FTIR-spectroscopy. Optical parameters are investigated using UV-VIS, PL and QY measurements. Several parameters such as concentration, excitation wavelength and pH are studied. Zeta-potential analysis indicate that pH-induced (de-)protonation processes of functional moieties directly affect the n-π* energy bands. This results in unique pH-dependent absorption and emission characteristics which are discussed on the specific chemical composition of each CD system. T2 - MRS 2019 CY - Boston, MA, USA DA - 03.12.2019 KW - Nanoparticle KW - Carbon dot KW - Surface chemistry KW - Fluorescence KW - PH KW - Ligand KW - FTIR KW - Synthesis KW - Characterization PY - 2019 AN - OPUS4-49968 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Nirmalananthan-Budau, Nithiya A1 - Moser, Marko A1 - Roloff, Alexander A1 - Rühle, Bastian A1 - Borcherding, H. A1 - Thiele, T. A1 - Schedler, U. T1 - Cleavable probes and catch and release assays for surface group quantification on 2D- and 3D-supports N2 - Surface functionalization of 2D- and 3D-supports and nanomaterials are nowadays at the core of many applications of functional materials in the life and material sciences. Examples range from membranes and microarrays over bead-based assays, immunoseparation, and next generation sequencing to nanometer-sized optical reporters, nanosensors, and magnetic and optical contrast agents. Typically performed functionalization procedures include silanization and grafting reactions with reactive monomers to introduce functional groups like amino or carboxylic acid groups and the attachment of ligands like polyethylene glycol (PEG) molecules and biomolecules such as peptides, proteins, and DNA.[1-3] We present here a versatile concept to quantify the number of bioanalytically relevant functional groups like carboxyl, amino, and aldehyde moieties through the specific binding and subsequent release of small reporter molecules such as fluorescent dyes and non-fluorescent chromophores utilizing cleavable linkers or the formation of cleavable bonds as a reversible covalent labeling strategy. This is representatively demonstrated for different types of nano- and microparticles with different labeling densities of carboxyl, amino, and aldehyde groups. This strategy enables to separate the signal-generating molecule from the bead surface, thereby circumventing uncertainties associated with light scattering, binding-induced changes in reporter fluorescence, and fluorescence quenching dye-dye interactions on crowded material surfaces.[1-3] Moreover, the reporters are chosen to be detectable with different analytical methods as prerequisite for straightforward validation via method compari-sons and mass balances. Applications of these assays and multimodal cleavable probes range from a quantitative comparison of bead batches and process control to a qualitative prediction of the coupling efficiencies in bioconjugation reactions. T2 - ANAKON 2019 CY - Münster, Germany DA - 25.03.2019 KW - Nanoparticle KW - Surface group KW - Surface analysis KW - Cleavable probe KW - Optical assay KW - Quality assurance KW - Conductometry KW - Dye labeling KW - Methos comparision PY - 2019 AN - OPUS4-47628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute ED - Kaiser, Martin ED - Würth, Christian ED - Kraft, Marco ED - Soukka, T. T1 - Explaining the influence of dopant concentration and excitation power density on the luminescence and brightness of β-NaYF4:Yb3+,Er3+ nanoparticles: Measurements and simulations N2 - We assessed the influence of Yb3+ and Er3+ dopant concentration on the relative spectral distribution, quantum yield (  UC), and decay kinetics of the upconversion luminescence (UCL) and particle brightness (BUC) for similarly sized (33 nm) oleate-capped -NaYF4:Yb3+,Er3+ upconversion (UC) nanoparticles (UCNPs) in toluene at broadly varied excitation power densities (P). This included an Yb3+ series where the Yb3+ concentration was varied between 11%–21% for a constant Er3+ concentration of 3%, and an Er3+ series, where the Er3+ concentration was varied between 1%–4% for a constant Yb3+ concentration of 14%. The results were fitted with a coupled rate equation model utilizing the UCL data and decay kinetics of the green and red Er3+ emission and the Yb3+ luminescence at 980 nm. An increasing Yb3+ concentration favors a pronounced triphotonic population of 4F9/2 at high P by an enhanced back energy transfer (BET) from the 4G11/2 level. Simultaneously, the Yb3+-controlled UCNPs absorption cross section overcompensates for the reduction in  UC with increasing Yb3+ concentration at high P, resulting in an increase in BUC. Additionally, our results show that an increase in Yb3+ and a decrease in Er3+ concentration enhance the color tuning range by P. These findings will pave the road to a deeper understanding of the energy transfer processes and their contribution to efficient UCL, as well as still debated trends in green-to-red intensity ratios of UCNPs at different P. KW - Nanoparticle KW - Lanthanide KW - Upconversion nanoparticle KW - Fluorescence KW - Integration sphere spectroscopy KW - Mechanism KW - Lifetime, synthesis KW - Surface chemistry KW - Yb(III) KW - Er(III) KW - Energy transfer KW - Absolute measurement KW - Quantum yield PY - 2019 U6 - https://doi.org/10.1007/s12274-019-2450-4 SN - 1998-0124 SN - 1998-0000 VL - 12 IS - 8 SP - 1871 EP - 1879 PB - Springer AN - OPUS4-48880 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brandl, F. A1 - Lederle, F. A1 - Härter, C. A1 - Thünemann, Andreas A1 - Beuermann, S. T1 - From gaseous vinylidene fluoride to electroactive poly(vinylidene fluoride) – Inducing β-phase by formation of block copolymers and composite materials N2 - Polymeric core-shell particles were synthesized in a semi-batch emulsion polymerization process. The shell of the particles consist of PVDF with a high amount of beta-phase. Small-angle X-ray scattering (SAXS) was used to quantify the size of the cores of the particles and the thickness of the shell. T2 - Macromolecular Colloquium Freiburg CY - Freiburg, Germany DA - 20.02.2019 KW - Small-angle x-ray scattering KW - SAXS KW - Nanoparticle KW - Polymer PY - 2019 AN - OPUS4-47467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tvrdonova, M. A1 - Vlcnovska, M. A1 - Pompeiano Vanickova, L. A1 - Kanicky, V. A1 - Adam, V. A1 - Ascher, Lena A1 - Jakubowski, Norbert A1 - Vaculovicova, M. A1 - Vaculovic, T. T1 - Gold nanoparticles as labels for immunochemical analysis using laser ablation inductively coupled plasma mass spectrometry N2 - In this paper, we describe the labelling of antibodies by gold nanoparticles (AuNPs) with diameters of 10 and 60 nm with detection by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Additionally, the AuNPs labelling strategy is compared with commercially available labelling reagents based on MeCAT (metal coded affinity tagging). Proof of principle experiments based on dot blot experiments were performed. The two labelling methods investigated were compared by sensitivity and limit of detection (LOD). The absolute LODs achieved were in the range of tens of picograms for AuNP labelling compared to a few hundred picograms by the MeCAT labelling. KW - Nanoparticle KW - LA-ICP-MS KW - Labeling PY - 2019 U6 - https://doi.org/10.1007/s00216-018-1300-7 SN - 1618-2642 SN - 1618-2650 VL - 411 IS - 3 SP - 559 EP - 564 PB - Springer-Verlag GmbH CY - Berlin, Heidelberg AN - OPUS4-47093 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Arakawa, Akihiro A1 - Jakubowski, Norbert A1 - Flemig, Sabine A1 - Koellensperger, G. A1 - Rusz, M. A1 - Iwahata, D. A1 - Traub, Heike A1 - Hirata, T. T1 - High-resolution laser ablation inductively coupled plasma mass spectrometry used to study transport of metallic nanoparticles through collagen-rich microstructures in fibroblast multicellular spheroids N2 - We have efficiently produced collagen-rich microstructures in fibroblast multicellular spheroids (MCSs) as a three-dimensional in vitro tissue analog to investigate silver (Ag) nanoparticle (NP) penetration. The MCS production was examined by changing the seeding cell number (500 to 40,000 cells) and the growth period (1 to 10 days). MCSs were incubated with Ag NP suspensions with a concentration of 5 μg/mL for 24 h. For this study, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to visualize Ag NP localization quantitatively. Thin sections of MCSs were analyzed by LA-ICP-MS with a laser spot size of 8 μm to image distributions of 109Ag, 31P, 63Cu, 66Zn, and 79Br. A calibration using a NP suspension was applied to convert the measured Ag intensity into the number of NPs present. The determined numbers of NPs ranged from 30 to 7200 particles in an outer rim of MCS. The particle distribution was clearly correlated with the presence of 31P and 66Zn and was localized in the outer rim of proliferating cells with a width that was equal to about twice the diameter of single cells. Moreover, abundant collagens were found in the outer rim of MCSs. For only the highest seeding cell number, NPs were completely captured at the outer rim, in a natural barrier reducing particle transport, whereas Eosin (79Br) used as a probe of small molecules penetrated into the core of MCSs already after 1 min of exposure. KW - Laser ablation KW - ICP-MS KW - Nanoparticle KW - Cell KW - Speroid PY - 2019 U6 - https://doi.org/10.1007/s00216-019-01827-w SN - 1618-2642 SN - 1618-2650 VL - 411 IS - 16 SP - 3497 EP - 3506 PB - Springer CY - Berlin, Heidelberg AN - OPUS4-47900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Arakawa, Akihiro A1 - Jakubowski, Norbert A1 - Koellensperger, G. A1 - Theiner, S. A1 - Schweikert, A. A1 - Flemig, Sabine A1 - Iwahata, D. A1 - Traub, Heike A1 - Hirata, T. T1 - Imaging of Ag NP transport through collagen-rich microstructures in fibroblast multicellular spheroids by high-resolution laser ablation inductively coupled plasma time-of-flight mass spectrometry N2 - We investigated the penetration of silver nanoparticles (Ag NPs) into a three-dimensional in vitro tissue analog using NPs with various sizes and surface coatings, and with different incubation times. A high-Resolution laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) time-of-flight (TOF) instrument was applied for imaging the distributions of elements in thin sample sections (20 μm thick). A fibroblast multicellular spheroid (MCS) was selected as the model system and cultured for more than 8 days to produce a natural barrier formed by the extracellular matrix containing collagen. The MCS was then exposed for up to 48 h to one of four types of Ag NPs (∅ 5 nm citrate coated, ∅ 20 nm citrate coated, ∅ 20 nm polyvinylpyrrolidone coated, and ∅ 50 nm citrate coated). Imaging showed that the penetration pathway was strongly related to steric networks formed by collagen fibrils, and Ag NPs with a hydrodynamic diameter of more than 41 nm were completely trapped in an outer rim of the MCSs even after incubation for 48 h. In addition, we examined the impact of these NPs on essential elements (P, Fe, Cu, and Zn) in areas of Ag NP accumulation. We observed a linear increase at the sub-femtogram level in the total concentration of Cu (fg per pixel) in samples treated with small or large Ag NPs (∅ 5 nm or ∅ 50 nm) for 48 h. KW - Nanoparticle KW - Laser ablation KW - ICP-MS KW - Imaging KW - Cell PY - 2019 U6 - https://doi.org/10.1039/c9an00856j SN - 0003-2654 VL - 144 IS - 16 SP - 4935 EP - 4942 PB - Royal Society of Chemistry RSC CY - Cambridge AN - OPUS4-48531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arakawa, Akihiro A1 - Jakubowski, Norbert A1 - Flemig, Sabine A1 - Koellensperger, G. A1 - Theiner, S. A1 - Schweikert, A. A1 - Iwahata, D. A1 - Traub, Heike A1 - Hirata, T. T1 - Localization of cells and exposed nanoparticles in three-dimensional in vitro tissue analog measured by means of an elemental microscopy based on LA-ICP-TOF-MS N2 - Metallic nanoparticles (NPs) are currently applied in a variety of consumer products and are also attractive for medical applications. With their widespread use, the potential for human exposure to NPs — either intended or unintended — is increasing. Therefore, many studies have evaluated the toxicity and transport mechanism of NPs. In comparison with two-dimensional cultured cells, multicellular spheroids (MCS) look promising to be used as a three-dimensional cellular model, having unique advantages in nanoparticle studies due to the fact that interactions with excreted extracellular matrix can be investigated. Fibroblast cells are one of the most important cell systems to express a microenvironment by excreting an abundant extracellular matrix. For bioimaging laser ablation inductively coupled-plasma mass spectrometry (LA-ICP-MS) is used in this investigation to study the interaction of metallic NPs with MCS for multi-element detection offering a wide dynamic range. As a mass spectrometer we have applied a time-of-flight (TOF) instrument for (quasi-) simultaneous detection of all isotopes of elements of interest. The aim of this study is to investigate the localization of silver (Ag) NPs exposed to fibroblast MCSs by means of LA-ICP-TOF-MS. In addition, for demonstrating elemental microscopy we chose phosphorous (31P) and iron (56Fe) to visualize regions of enriched extracellular matrix and single cells, respectively. In this presentation, we show that exposed Ag NPs are highly accumulated at the same position of single cells in an outer rim of fibroblast MCSs. T2 - 7th International Symposium on Metallomics CY - Warsaw, Poland DA - 30.06.2019 KW - Nanoparticle KW - Laser ablation KW - ICP-MS KW - Multicellular spheroid PY - 2019 AN - OPUS4-48425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute T1 - Luminescence measurements, calibration strategies and photoluminescence quantum yields N2 - Different types of optical spectroscopies are introduced with special emphasis on method-inherent limitations and reliable instrument calibration and performance validation. In addition, procedures for the determination of spectroscopic key parameters like the photoluminescence quantum yield are presented including required instrument calibrations and material-specific effects related to certain emitters. T2 - Fakultät der University of Ottawa CY - Ottawa, Canada DA - 11.12.2018 KW - Quality assurcance KW - Optical spectroscopy KW - Method comparison KW - Photoluminescence KW - Calibration KW - Performance validation KW - Dye KW - Nanoparticle KW - Quantum dots KW - Quantum yields KW - Uncertainty KW - Method validation PY - 2019 AN - OPUS4-47630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -