TY - JOUR A1 - Meng, M. A1 - Zhang, T. A1 - Wang, J. A1 - Cheng, Z. A1 - Liu, Y. A1 - Qiao, X. A1 - Wen, J. A1 - Resch-Genger, Ute A1 - Long, W. A1 - Ou, J. T1 - NaYF4:Yb3+/Tm3+@NaYF4:Yb3+ Upconversion Nanoparticles for Optical Temperature Monitoring and Self-Heating in Photothermal Therapy N2 - The core−shell NaYF4:Yb3+/Tm3+@NaYF4:Yb3+ upconversion nanoparticles were successfully prepared by a solvothermal method, and a layer of mesoporous silica (mSiO2) was successfully coated on the periphery of the core−shell nanoparticles to transform their surface from lipophilic to hydrophilic, further expanding their applications in biological tissues. The physical phase, morphology, structure, and fluorescence properties were characterized by X-ray diffraction (XRD), field emission transmission electron microscopy (TEM), Fourier infrared spectroscopy (FT-IR), ζ potential analysis, and fluorescence spectroscopy. It was found that the material has a hexagonal structure with good hydrophilicity and emits intense fluorescence under 980 nm pump laser excitation. The non-contact temperature sensing performance of nanoparticles was evaluated by analyzing the upconversion fluorescence of Tm3+ (1G4 → 3F4 and 3F3 → 3H6) in the temperature range of 284−344 K. The absolute and relative sensitivities were found to be 0.0067 K−1 and 1.08 % K−1, respectively, with high-temperature measurement reliability and good temperature cycling performance. More importantly, its temperature measurement in phosphate-buffered saline (PBS) solution is accurate. In addition, the temperature of the cells can be increased by adjusting the laser power density and laser irradiation time. Therefore, an optical temperature sensing platform was built to realize the application of real-time monitoring of cancer cell temperature and the dual function of photothermal therapy. KW - Sensor KW - Temperature KW - Lanthanide KW - Tag KW - Fluorescence KW - Nanoparticles KW - Synthesis KW - Environment KW - Monitoring KW - Sensing KW - Nano KW - Life sciences KW - Upconversion PY - 2023 DO - https://doi.org/10.1021/acsanm.2c05110 VL - 6 IS - 1 SP - 759 EP - 771 PB - ACS Publications AN - OPUS4-57081 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stein, L. A1 - Wang, Cui A1 - Förster, C. A1 - Resch-Genger, Ute A1 - Heinze, K. T1 - Bulky ligands protect molecular ruby from oxygen quenching N2 - Chromium(III) complexes can show phosphorescence from the spin-flip excited doublet states 2E/2T1 in the near-infrared with high photoluminescence quantum yields and extremely long lifetimes in the absence of dioxygen. The prototype molecular ruby, [Cr(ddpd)2]3+ (ddpd = N,N’-dimethyl-N,N’-dipyridine-2-ylpyridine-2,6-diamine), has a photoluminescence quantum yield and a luminescence lifetime of 13.7% and 1.1 ms in deaerated acetonitrile, respectively. However, its luminescence is strongly quenched by 3O2 via an efficient Dexter-type energy transfer process. To enable luminescence applications of molecular rubies in solution under aerobic conditions, we explored the potential of sterically demanding ddpd ligands to shield the chromium(III) center from O2 using steady state and time-resolved photoluminescence spectroscopy. The structures of the novel complexes with sterically demanding ligands were investigated by single crystal X-ray diffraction and quantum chemically by density functional theory calculations. The O2 sensitivity of the photoluminescence was derived from absolutely measured photoluminescence quantum yields and excited state lifetimes under inert and aerobic conditions and by Stern–Volmer analyses of these data. Optimal sterically shielded chromium(III) complexes revealed photoluminescence quantum yields of up to 5.1% and excited state lifetimes of 518 μs in air-saturated acetonitrile, underlining the large potential of this ligand design approach to broaden the applicability of highly emissive chromium(III) complexes. KW - Fluorescence KW - Synthesis KW - Production KW - Optical spectroscopy KW - Ligand KW - Photophysics KW - Cr(III) KW - Mechanism KW - NIR KW - Sensor KW - Oxygen PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570807 DO - https://doi.org/10.1039/d2dt02950b VL - 51 IS - 46 SP - 17664 EP - 17670 PB - The Royal Society of Chemistry CY - Berlin AN - OPUS4-57080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Billimoria, K. A1 - Diaz Fernandez, Y. A. A1 - Andresen, Elina A1 - Sorzabal-Bellido, I. A1 - Huelga-Suarez, G. A1 - Bartczak, D. A1 - Ortiz de Solórzano, C. A1 - Resch-Genger, Ute A1 - Goenaga Infante, H. T1 - The potential of bioprinting for preparation of nanoparticle-based calibration standards for LA-ICP-ToF-MS quantitative imaging N2 - This paper discusses the feasibility of a novel strategy based on the combination of bioprinting nano-doping technology and laser ablation-inductively coupled plasma time-of-flight mass spectrometry analysis for the preparation and characterization of gelatin- based multi-element calibration standards suitable for quantitative imaging. To achieve this, lanthanide up-conversion nanoparticles were added to a gelatin matrix to produce the bioprinted calibration standards. The features of this bioprinting approach were com- pared with manual cryosectioning standard preparation, in terms of throughput, between batch repeatability and elemental signal homogeneity at 5 μm spatial resolution. By using bioprinting, the between batch variability for three independent standards of the same concentration of 89 Y (range 0–600 mg/kg) was reduced to 5% compared to up to 27% for cryosectioning. On this basis, the relative standard deviation ( RSD ) obtained between three independent calibration slopes measured within 1 day also reduced from 16% (using cryosectioning ) to 5% (using bioprinting), supporting the use of a single standard preparation replicate for each of the concentrations to achieve good calibration performance using bioprinting. This helped reduce the analysis time by approximately 3-fold. With cryosectioning each standard was prepared and sectioned individually, whereas using bio-printing it was possible to have up to six different standards printed simultaneously, reducing the preparation time from approximately 2 h to under 20 min (by approxi- mately 6-fold). The bio-printed calibration standards were found stable for a period of 2 months when stored at ambient temperature and in the dark. KW - Environmental analysis KW - LA-ICP-MS KW - Lanthanide KW - Tag KW - Fluorescence KW - Nanoparticles KW - Reference material KW - Quality assurance KW - 3D-printing KW - Synthesis KW - Production KW - Multimodal PY - 2022 DO - https://doi.org/10.1093/mtomcs/mfac088 SN - 1756-591X VL - 14 IS - 12 SP - 1 EP - 9 PB - Oxford University Press CY - Oxford AN - OPUS4-57018 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Burnage, Samual A1 - Bell, Jérémy A1 - Wan, Wei A1 - Kislenko, Evgeniia A1 - Rurack, Knut T1 - Combining a hybrid chip and tube microfluidic system with fluorescent molecularly imprinted polymer (MIP) core–shell particles for the derivatisation, extraction, and detection of peptides with N-terminating phosphorylated tyrosine N2 - The reliable identification and quantitation of phosphorylated amino acids, peptides and proteins is one of the key challenges in contemporary bioanalytical research, an area of particular interest when attempting to diagnose and treat diseases at an early stage. We have developed a synthetic probe for targeting phosphorylated amino acids, based on core–shell submicron-sized particles consisting of a silica core, coated with a molecularly imprinted polymer (MIP) shell. The MIP layer contains a fluorescent probe crosslinker which binds selectively to phosphorylated tyrosine (pY) moieties with a significant imprinting factor (IF) and responds with a "light-up” fluorescence signal. The bead-based ratiometric detection scheme has been successfully transferred to a microfluidic chip format and its applicability to rapid assays has been exemplarily shown by discriminating a pY-terminating oligopeptide against its nonphosphorylated counterpart. Such miniaturised devices could lead to an automated pY or pY N-terminated peptide measurement system in the future. The setup combines a modular microfluidic system for amino acid derivatisation, extraction (by micropillar co-flow) and selective adsorption and detection with the fluorescent MIP core–shell particle probes. A miniaturised optical assembly for low-light fluorescence measurements was also developed, based on miniaturised opto-electronic parts and optical fibres. The emission from the MIP particles upon binding of pY or pY N-terminated peptides could be monitored in real-time. KW - Microfluidics KW - Molecularly imprinted polymers KW - Phosphorylated peptides KW - Fluorescence KW - Core-shell particles PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569204 DO - https://doi.org/10.1039/d2lc00955b SN - 1473-0197 VL - 23 IS - 3 SP - 466 EP - 474 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-56920 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scholtz, Lena T1 - Luminescent Polymer Microbeads – Synthesis & Applications N2 - Differently sized, luminescent polymer beads encoded with QDs were prepared with a simple, optimized polymerization procedure. The optical properties of the resulting particles were studied to ensure sufficient fluorescence. In addition, possible future applications were identified. T2 - Future WiNS: New Energies for a Sustainable World CY - Berlin, Germany DA - 07.12.2022 KW - Polymerization KW - Quantum dots KW - Fluorescence KW - Luminescence PY - 2022 AN - OPUS4-56560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Güttler, Arne A1 - Richter, Maria A1 - Würth, Christian A1 - Resch-Genger, Ute T1 - New Reference Materials for Quantification and Standardization of Fluorescence-based Measurements N2 - Luminescence techniques are amongst the most commonly used analytical methods in the life and material sciences due to their high sensitivity and non-destructive and multiparametric character. Photoluminescence signals are, however, affected by wavelength-, polarization-, and time-dependent instrument specific effects and the compound-specific photoluminescence quantum yield. The former hamper the comparability of fluorescence measurements, while the relative determination of the latter requires suitable quantum yield standards with well-known photoluminescence quantum yields. For the simple correction of instrument specific effects in the wavelength region of 300 nm to 950 nm, the set of the five certified spectral fluorescence standards (CRM) BAM-F001 – BAM-F005, has been extended to the NIR range by including two new fluorescence standards currently under certification. T2 - 17th conference on Methods and Applications in Fluorescence CY - Gothenburg, Sweden DA - 11.09.2022 KW - Luminescence KW - Photoluminescence KW - Fluorescence KW - Quantum yield KW - Certified reference material KW - Standard PY - 2022 AN - OPUS4-56441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wegner, Karl David T1 - Luminescent Quantum dots – the next-generation nano light bulbs N2 - Fluorescent semiconductor nanocrystals, also known as quantum dots (QDs), enabled many advancements in biotechnology, photovoltaics, photocatalysis, quantum computing and display devices. The high versatility of this nanomaterial is based on their unique size-tunable photoluminescence properties, which can be adjusted from the visible to the near-infrared range. In contrast to other nanomaterials, QDs made the transition from a laboratory curiosity to the utilization in commercial products, like the QLED television screen or in smartphone displays. The best investigated QDs are composed of heavy metals like cadmium or lead, which is not the best choice in terms of toxicity and environmental pollution. A more promising material is Indium Phosphide (InP), which is also currently used by Samsung, Sony and co. in the QLED displays. In this contribution, I would like to give you a sneak peek behind the curtains of nanomaterial synthesis and show how this material is produced, how to stabilize their structural properties, and assess their toxicity in environmentally relevant conditions. Furthermore, I would like to present a synthesis method to accomplish the last open challenge in display technology of a blue luminescent LED based on QDs by introducing a new element to the InP QDs. T2 - The Berlin Postdoc Day CY - Berlin, Germany DA - 03.11.2022 KW - InP KW - Quantum dots KW - Fluorescence KW - Aging KW - Doping KW - Nanomaterial KW - Cytotoxicity PY - 2022 AN - OPUS4-56194 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scholtz, Lena T1 - Luminescence encoding of polymer microbeads with nanocrystals during polymerization N2 - The Goal & Motivation - Spherical polymer beads - Controlled size in the low µm range - Narrow size distribution - Homogeneous encoding with molecular and nanoscale luminophores (dyes , QDs, platelets etc.) - Sufficient fluorescence - Easy, accessible procedure T2 - GrK Nanohybrid Conference CY - Hamburg, Germany DA - 04.10.2022 KW - Polymerization KW - Nanocrystals KW - Fluorescence KW - Microbeads PY - 2022 AN - OPUS4-56028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Güttler, Arne A1 - Richter, Maria A1 - Würth, Christian A1 - Resch-Genger, Ute T1 - New Reference Materials for the Quantification and Standardization of Fluorescence-based Measurements N2 - Luminescence techniques are amongst the most commonly used analytical methods in the life and material sciences due to their high sensitivity and non-destructive and multiparametric character. Photoluminescence signals are, however, affected by wavelength-, polarization-, and time-dependent instrument specific effect and the compound-specific photoluminescence quantum yield. The former hamper the comparability of fluorescence measurements, while the relative determination of the latter requires suitable quantum yield standards with well-known photoluminescence quantum yields (QY). For the simple correction of instrument specific effects in the wavelength region of 300 nm to 950 nm, the set of the five certified spectral fluorescence standards BAM-F001 – BAM-F005, has been extended to the NIR range by including two new fluorescence standards currently under certification. For the reliable and accurate determination of QY which is the key performance parameter for the comparison of different luminophores, we certified a set of 12 quantum yield standards, which absorb and emit in the wavelength range from 300 nm to 1000 nm. T2 - Methods and Applications in Fluorescence CY - Gothenburg, Sweden DA - 11.09.2022 KW - Luminescence KW - Photoluminescence KW - Fluorescence KW - Quantum yield KW - Certified reference material KW - Standard PY - 2022 AN - OPUS4-55914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute A1 - Meermann, Björn A1 - Koch, Matthias A1 - Weller, Michael G. T1 - Editorial: Analytical methods and applications in materials and life sciences N2 - Current trends in materials and life sciences are flanked by the need to push detection limits to single molecules or single cells, enable the characterization of increasingly complex matrices or sophisticated nanostructures, speed up the time of analysis, reduce instrument complexity and costs, and improve the reliability of data. This requires suitable analytical tools such as spectroscopic, separation and imaging techniques, mass spectrometry, and hyphenated techniques as well as sensors and their adaptation to application-specific challenges in the environmental, food, consumer product, health sector, nanotechnology, and bioanalysis. Increasing concerns about health threatening known or emerging pollutants in drinking water, consumer products, and food and about the safety of nanomaterials led to a new awareness of the importance of analytical sciences. Another important driver in this direction is the increasing demand by legislation, particularly in view of the 17 sustainable development goals by the United Nations addressing clean energy, industry, and innovation, sustainable cities, clean water, and responsible consumption and production. In this respect, also the development of analytical methods that enable the characterization of material flows in production processes and support recycling concepts of precious raw materials becomes more and more relevant. In the future, this will provide the basis for greener production in the chemical industry utilizing recycled or sustainable starting materials. This makes analytical chemistry an essential player in terms of the circular economy helping to increase the sustainability of production processes. In the life sciences sector, products based on proteins, such as therapeutic and diagnostic antibodies, increase in importance. These increasingly biotechnologically produced functional biomolecules pose a high level of complexity of matrix and structural features that can be met only by highly advanced methods for separation, characterization, and detection. In addition, metrological traceability and target definition are still significant challenges for the future, particularly in the life sciences. However, innovative reference materials as required for the health and food sector and the characterization of advanced materials can only be developed when suitable analytical protocols are available. The so-called reproducibility crisis in sciences underlines the importance of improved measures of quality control for all kinds of measurements and material characterization. This calls for thorough method validation concepts, suitable reference materials, and regular interlaboratory comparisons of measurements as well as better training of scientists in analytical sciences. The important contribution of analytical sciences to these developments is highlighted by a broad collection of research papers, trend articles, and critical reviews from these different application fields. Special emphasis is dedicated to often-overlooked quality assurance and reference materials. T2 - 150 years BAM: Science with impact CY - Berlin, Germany DA - 01.01.2021 KW - Analysis KW - Life sciences KW - Analytical sciences KW - Quality assurance KW - Reference material KW - Fluorescence KW - Nanoparticle KW - Sensor KW - Material sciences KW - Pollutant KW - Environment KW - Method KW - Limit of detection KW - 150th anniversary KW - ABC KW - BAM KW - Collection KW - Editorial KW - Special issue KW - Bundesanstalt für Materialforschung und -prüfung KW - Jahrestag PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550720 DO - https://doi.org/10.1007/s00216-022-04082-8 SN - 1618-2642 SN - 1618-2650 VL - 414 IS - Topical collection: Analytical methods and applications in the materials and life sciences SP - 4267 EP - 4268 PB - Springer CY - Berlin AN - OPUS4-55072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR ED - Resch-Genger, Ute ED - Koch, Matthias ED - Meermann, Björn ED - Weller, Michael G. T1 - Topical collection: Analytical methods and applications in the materials and life sciences N2 - Current trends in materials and life sciences are flanked by the need to push detection limits to single molecules or single cells, enable the characterization of increasingly complex matrices or sophisticated nanostructures, speed up the time of analysis, reduce instrument complexity and costs, and improve the reliability of data. This requires suitable analytical tools such as spectroscopic, separation and imaging techniques, mass spectrometry, and hyphenated techniques as well as sensors and their adaptation to application-specific challenges in the environmental, food, consumer product, health sector, nanotechnology, and bioanalysis. Increasing concerns about health threatening known or emerging pollutants in drinking water, consumer products, and food and about the safety of nanomaterials led to a new awareness of the importance of analytical sciences. Another important driver in this direction is the increasing demand by legislation, particularly in view of the 17 sustainable development goals by the United Nations addressing clean energy, industry, and innovation, sustainable cities, clean water, and responsible consumption and production. In this respect, also the development of analytical methods that enable the characterization of material flows in production processes and support recycling concepts of precious raw materials becomes more and more relevant. In the future, this will provide the basis for greener production in the chemical industry utilizing recycled or sustainable starting materials. This makes analytical chemistry an essential player in terms of the circular economy helping to increase the sustainability of production processes. In the life sciences sector, products based on proteins, such as therapeutic and diagnostic antibodies, increase in importance. These increasingly biotechnologically produced functional biomolecules pose a high level of complexity of matrix and structural features that can be met only by highly advanced methods for separation, characterization, and detection. In addition, metrological traceability and target definition are still significant challenges for the future, particularly in the life sciences. However, innovative reference materials as required for the health and food sector and the characterization of advanced materials can only be developed when suitable analytical protocols are available. The so-called reproducibility crisis in sciences underlines the importance of improved measures of quality control for all kinds of measurements and material characterization. This calls for thorough method validation concepts, suitable reference materials, and regular interlaboratory comparisons of measurements as well as better training of scientists in analytical sciences. The important contribution of analytical sciences to these developments is highlighted by a broad collection of research papers, trend articles, and critical reviews from these different application fields. Special emphasis is dedicated to often-overlooked quality assurance and reference materials. T2 - 150 years BAM: Science with impact CY - Berlin, Germany DA - 01.01.2021 KW - 150th anniversary KW - ABC KW - Analysis KW - Analytical sciences KW - BAM KW - Collection KW - Environment KW - Fluorescence KW - Life sciences KW - Limit of detection KW - Material sciences KW - Method KW - Nanoparticle KW - Pollutant KW - Quality assurance KW - Reference material KW - Sensor KW - Special issue KW - Bundesanstalt für Materialforschung und -prüfung KW - Jahrestag PY - 2022 UR - https://link.springer.com/journal/216/topicalCollection/AC_16a2ef9b81853377e321ef84d9c4a431 SN - 1618-2642 SN - 1618-2650 VL - 414 SP - 4267 EP - 4529 PB - Springer CY - Berlin AN - OPUS4-55670 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Srivastava, Priyanka T1 - Multi-color nanosensors for ratiometric measurements of acidic, neutral, and basic pH based on silica and polystyrene particles N2 - pH presents one of the most important analytes in the life and material sciences, indicating, e.g., diseases and corrosion processes. This includes the optical monitoring of pH in living cells for studying cellular internalization pathways, such as phagocytosis, endocytosis, and receptor mediated internalization with the aid of molecular and nanoscale fluorescent sensors. Nanoparticle (NP)-based sensors, that are labelled or stained with a multitude of sensor dyes, have several advantages as compared to conventional molecular probes like enhanced brightness, i.e., amplified signals, ease of designing ratiometric systems by combining analyte-sensitive and inert reference dyes, and increased photostability. Moreover, this can enable the use of hydrophobic dyes in aqueous environments. Versatile templates and carriers for the fabrication of nanosensors by staining and/or labelling with different fluorophores and sensor molecules are surface-functionalized particles like silica (SiO2) and polystyrene (PS) particles. Here we present a platform of blue-red-green fluorescent pH nanosensors for the measurement of acidic, neutral, and basic pH utilizing both types of matrices and two spectrally distinguishable sensor dyes with an integrated reference dye and demonstrate its applicability for cellular studies. T2 - E-MRS Spring Meeting 2022 CY - Online meeting DA - 30.05.2022 KW - Nanosensors KW - pH sensing KW - Silica- and polystyrene particles KW - Ratiometric sensors KW - Fluorescence PY - 2022 AN - OPUS4-55597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Thekkeppat, N. P. A1 - Bhattacharya, Biswajit A1 - Tothadi, S. A1 - Ghosh, S. T1 - Mechanically flexible crystals of styryl quinoline derivatives N2 - Herein, we report three crystals of styryl quinoline derivatives. All these three crystals are mechanically flexible crystals, isostructural and also all of them comply with the common underlying features for elas- tic flexibility like absence of slip plane, criss-cross packing arrangement of neighbouring tapes, presence of weak and dispersive interactions such as halogen bonds, hydrogen bonds etc. The interactions facilitate easy movement of molecules under application of pressure thereby imparting elasticity. Further, the crys- tals were found to be blue light emitting making them promising candidates for optical waveguides. The optical properties were combined with flexibility by using crystal engineering approach towards achiev- ing various applications such as flexible OLEDs, optical waveguides, flexible optoelectronics etc. KW - Mechanical flexibility KW - Halogen bond KW - Fluorescence PY - 2022 DO - https://doi.org/10.1016/j.molstruc.2022.133293 SN - 0022-2860 VL - 1265 SP - 1 EP - 7 PB - Elsevier CY - Amsterdam AN - OPUS4-55549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meng, M. A1 - Zhang, T. A1 - Wang, J. A1 - Cheng, Z. A1 - Yang, J. A1 - Qiao, X. A1 - Wen, J. A1 - Resch-Genger, Ute A1 - Ou, J. T1 - Fluorescence temperature sensing of NaYF4:Yb3+/Tm3+@NaGdF4:Nd3+/Yb3+ nanoparticles at low and high temperatures N2 - NaYF4:Yb3+/Tm3+@NaGdF4:Nd3+/Yb3+ upconversion nanoparticles (UCNPs) were prepared using a solvothermal method, and the effects of key factors such as the content of sensitiser Nd 3+ and Yb3+ on their luminescence properties were investigated. The nanoparticles are homogeneous in size and well dispersed. Under 808 nm excitation, it can produce strong upconversion fluorescence. At the same time, the nanoparticles have good temperature-sensing properties at the thermally coupled energy levels of 700 nm and 646 nm for Tm3+. Using its fluorescence intensity ratio (FIR), accurate temperature measurements can be performed, and it has been found that it exhibits different temperature sensing properties in low and high-temperature regions. The maximum relative sensitivity was found to be 0.88% K-1 and 1.89% K-1 for the lowtemperature region of 285 K-345 K and the high-temperature region of 345 K-495 K. The nanoparticles were applied to the internal temperature measurement of lithium batteries and the actual high-temperature environment, respectively, and were found to have good temperature measurementt performance. KW - Fluorescence KW - Sensor KW - Temperature KW - Ratiometric KW - Lanthanide KW - Quantum yield KW - Integrating sphere spectroscopy KW - Absolute fluorescence KW - Quality assurance KW - Nano KW - Particle KW - Application KW - Upconversion nanoparticle PY - 2022 DO - https://doi.org/10.1088/1361-6528/ac84e4 SN - 1361-6528 VL - 33 IS - 34 SP - 1 EP - 15 PB - IOP Publishing CY - Bristol AN - OPUS4-55454 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stroyuk, O. A1 - Raievska, O. A1 - Barabash, A. A1 - Batentschuk, M. A1 - Osvet, A. A1 - Fiedler, Saskia A1 - Resch-Genger, Ute A1 - Hauch, J. A1 - Brabec, C. J. T1 - "Green" synthesis of highly luminescent lead-free Cs2AgxNa1-xBiyIn1-yCl6 perovskites N2 - A new “green” and mild synthesis of highly stable microcrystalline Cs2AgxNa1-xBiyIn1-yCl6 (CANBIC) perovskites under ambient conditions was developed that is scalable to the multi-gram production. Under UV illumination, the CANBIC perovskites emit intense broadband photoluminescence (PL) with a quantum yield (QY) of 92% observed for x = 0.35 and y = 0.01-0.02. The combination of strong UV absorbance and broadband visible emission, high PL QY, and long PL lifetimes of up to 1.4 μs, along with an outstanding stability makes these CANBICs a promising material class for many optical applications. KW - Fluorescence KW - Perovskites KW - Solar cell KW - Automated synthesis KW - Green synthesis KW - Quantum yield KW - Integrating sphere spectroscopy KW - Absolute fluorescence KW - Quality assurance KW - Nano KW - Particle KW - Application KW - Semiconductor KW - Quantum dot KW - Renewable energy PY - 2022 DO - https://doi.org/10.1039/d2tc02055f SN - 2050-7526 VL - 10 IS - 27 SP - 9938 EP - 9944 PB - Royal Society of Chemistry AN - OPUS4-55453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scholtz, Lena T1 - Luminescence Encoding of Polymer Microbeads during Polymerization N2 - Differently sized, luminescent polymer beads encoded with QDs were prepared with a simple, optimized procedure. The optical properties of the resulting particles were studied to ensure sufficient fluorescence and to evaluate the influence of the polymerization on QD fluorescence. T2 - 84th Prague Meeting on Macromolecules - Frontiers of Polymer Colloids CY - Prague, Czech Republic DA - 24.07.2022 KW - Polymerization KW - Fluorescence KW - Quantum dots KW - Microbeads PY - 2022 AN - OPUS4-55447 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Srivastava, Priyanka A1 - Tavernaro, Isabella A1 - Genger, C. A1 - Welker, P. A1 - Huebner, Oskar A1 - Resch-Genger, Ute T1 - Multicolor Polystyrene Nanosensors for the Monitoring of Acidic, Neutral, and Basic pH Values and Cellular Uptake Studies N2 - A first tricolor fluorescent pH nanosensor is presented, which was rationally designed from biocompatible carboxylated polystyrene nanoparticles and two analyte-responsive molecular fluorophores. Its fabrication involved particle staining with a blue-red-emissive dyad, consisting of a rhodamine moiety responsive to acidic pH values and a pH-inert quinoline fluorophore, followed by the covalent attachment of a fluorescein dye to the particle surface that signals neutral and basic pH values with a green fluorescence. These sensor particles change their fluorescence from blue to red and green, depending on the pH and excitation wavelength, and enable ratiometric pH measurements in the pH range of 3.0−9.0. The localization of the different sensor dyes in the particle core and at the particle surface was confirmed with fluorescence microscopy utilizing analogously prepared polystyrene microparticles. To show the application potential of these polystyrene-based multicolor sensor particles, fluorescence microscopy studies with a human A549 cell line were performed, which revealed the cellular uptake of the pH nanosensor and the differently colored emissions in different cell organelles, that is, compartments of the endosomal-lysosomal pathway. Our results demonstrate the underexplored potential of biocompatible polystyrene particles for multicolor and multianalyte sensing and bioimaging utilizing hydrophobic and/or hydrophilic stimuli-responsive luminophores. KW - Microparticle KW - Fluorescence KW - Sensor KW - pH KW - Quantum yield KW - Multiplexing KW - Imaging KW - Cell KW - Quality assurance KW - Nano KW - Polymer KW - Bioimaging KW - Particle KW - Application PY - 2022 DO - https://doi.org/10.1021/acs.analchem.2c00944 VL - 94 IS - 27 SP - 9656 EP - 9664 PB - ACS AN - OPUS4-55365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scholtz, Lena A1 - Eckert, J. G. A1 - Elahi, T. A1 - Lübkemann, F. A1 - Hübner, Oskar A1 - Bigall, N. C. A1 - Resch-Genger, Ute T1 - Luminescence encoding of polymer microbeads with organic dyes and semiconductor quantum dots during polymerization N2 - Luminescence-encoded microbeads are important tools for many applications in the life and material sciences that utilize luminescence detection as well as multiplexing and barcoding strategies. The preparation of such beads often involves the staining of premanufactured beads with molecular luminophores using simple swelling procedures or surface functionalization with layer-by-layer (LbL) techniques. Alternatively, these luminophores are sterically incorporated during the polymerization reaction yielding the polymer beads. The favorable optical properties of semiconductor quantum dots (QDs), which present broadly excitable, size-tunable, narrow emission bands and low photobleaching sensitivity, triggered the preparation of beads stained with QDs. However, the colloidal nature and the surface chemistry of these QDs, which largely controls their luminescence properties, introduce new challenges to bead encoding that have been barely systematically assessed. To establish a straightforward approach for the bead encoding with QDs with minimized loss in luminescence, we systematically assessed the incorporation of oleic acid/oleylamine-stabilized CdSe/CdS-core/shell-QDs into 0.5–2.5 μm-sized polystyrene (PS) microspheres by a simple dispersion polymerization synthesis that was first optimized with the organic dye Nile Red. Parameters addressed for the preparation of luminophore-encoded beads include the use of a polymer-compatible ligand such as benzyldimethyloctadecylammonium chloride (OBDAC) for the QDs, and crosslinking to prevent luminophore leakage. The physico-chemical and optical properties of the resulting beads were investigated with electron microscopy, dynamic light scattering, optical spectroscopy, and fluorescence microscopy. Particle size distribution, fluorescence quantum yield of the encapsulated QDs, and QD leaking stability were used as measures for bead quality. The derived optimized bead encoding procedure enables the reproducible preparation of bright PS microbeads encoded with organic dyes as well as with CdSe/CdS-QDs. Although these beads show a reduced photoluminescence quantum yield compared to the initially very strongly luminescent QDs, with values of about 35%, their photoluminescence quantum yield is nevertheless still moderate. KW - Polymerization KW - Quantum dots KW - Microbeads KW - Fluorescence PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-553430 DO - https://doi.org/10.1038/s41598-022-16065-x SN - 2045-2322 VL - 12 SP - 1 EP - 16 PB - Nature Publishing Group CY - London AN - OPUS4-55343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bertorelle, F. A1 - Wegner, Karl David A1 - Berkulic, M. P. A1 - Fakhouri, H. A1 - Comby-Zerbino, C. A1 - Sagar, A. A1 - Bernadó, P. A1 - Resch-Genger, Ute A1 - Bonacic-Koutecký, V. A1 - Le Guével, X. A1 - Antoine, R. T1 - Tailoring the NIR-II Photoluminescence of Single Thiolated Au25 Nanoclusters by Selective Binding to Proteins N2 - Atomically precise gold nanoclusters are a fascinating class of nanomaterials that exhibit molecule-like properties and have outstanding photoluminescence (PL). Their ultrasmall size, molecular chemistry, and biocompatibility make them extremely appealing for selective biomolecule labeling in investigations of biological mechanisms at the cellular and anatomical levels. In this work, we report a simple route to incorporate a preformed Au25 nanocluster into a model bovine serum albumin (BSA) protein. A new approach combining small-angle X-ray scattering and molecular modeling provides a clear localization of a single Au25 within the protein to a cysteine residue on the gold nanocluster surface. Attaching Au25 to BSA strikingly modifies the PL properties with enhancement and a redshift in the second near-infrared (NIR-II) window. This study paves the way to conrol the design of selective sensitive probes in biomolecules through a ligand-based strategy to enable the optical detection of biomolecules in a cellular environment by live imaging. KW - Fluorescence KW - Aggregation KW - Signal enhancement KW - Cluster KW - Nano KW - Metal KW - NIRII KW - SWIR KW - Sensor KW - Quantum yield KW - Lifetime KW - Photophysics KW - Synthesis KW - Protein KW - Imaging KW - Bioimaging KW - Ligand KW - Gold PY - 2022 DO - https://doi.org/10.1002/chem.202200570 SN - 1521-3765 VL - 28 IS - 39 SP - 1 EP - 8 PB - Wiley-VCH CY - Weinheim AN - OPUS4-55077 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kromer, C. A1 - Schwibbert, Karin A1 - Gadicherla, A. K. A1 - Thiele, Dorothea A1 - Nirmalananthan-Budau, Nithiya A1 - Laux, P. A1 - Resch-Genger, Ute A1 - Luch, A. A1 - Tschiche, H. R. T1 - Monitoring and imaging pH in biofilms utilizing a fluorescent polymeric nanosensor N2 - Biofilms are ubiquitous in nature and in the man-made environment. Given their harmful effects on human health, an in-depth understanding of biofilms and the monitoring of their formation and growth are important. Particularly relevant for many metabolic processes and survival strategies of biofilms is their extracellular pH. However, most conventional techniques are not suited for minimally invasive pH measurements of living biofilms. Here, a fluorescent nanosensor is presented for ratiometric measurements of pH in biofilms in the range of pH 4.5–9.5 using confocal laser scanning microscopy. The nanosensor consists of biocompatible polystyrene nanoparticles loaded with pH-inert dye Nile Red and is surface functionalized with a pH-responsive fluorescein dye. Its performance was validated by fluorometrically monitoring the time-dependent changes in pH in E. coli biofilms after glucose inoculation at 37 °C and 4 °C. This revealed a temperature-dependent decrease in pH over a 4-h period caused by the acidifying glucose metabolism of E. coli. These studies demonstrate the applicability of this nanosensor to characterize the chemical microenvironment in biofilms with fluorescence methods. KW - Dye KW - Fluorescence KW - Signal enhancement KW - Sensor KW - Quantum yield KW - Synthesis KW - Nanoparticle KW - Nano KW - Polymer KW - Ph KW - Biofilm KW - MIC KW - Corrosion KW - Microorganism KW - Bacteria PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550751 DO - https://doi.org/10.1038/s41598-022-13518-1 SN - 2045-2322 VL - 12 IS - 1 SP - 1 EP - 10 PB - Nature Publishing Group CY - London AN - OPUS4-55075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -