TY - CONF
A1 - Güttler, Arne
T1 - Certified Reference Materials for the Quantification and Standardization of Fluorescence-based Measurements
N2 - The size and shape of photoluminescence signals is affected by wavelength-, polarization-, and time-dependent instrumentspecific contributions and the compound- and environment-specific photoluminescence quantum yield. The former hamper the comparability of fluorescence measurements performed on different measuring devices. The commonly relatively done determination of the performance parameter requires suitable quantum yield standards with well-known. The performance of such measurements is, e.g., described in the written standard IEC 62607 currently revised.
T2 - Colloquium für Optische Spektrometrie 2025
CY - Jena, Germany
DA - 24.09.2025
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Advanced material
KW - Calibration
KW - Characterization
KW - Fluorescence quantum yield
KW - Phosphor
KW - Absolute
KW - Integrating sphere spectroscopy
KW - Dye
KW - Standardization
KW - Reference material
KW - Interlaboratory comparison
KW - Uncertainty
PY - 2025
AN - OPUS4-64213
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Matiushkina, Anna
T1 - Quantification of Citrate Ligands on the Surface of Nanoparticles
N2 - In this study, different methods for determining nanoparticle surface ligands including thermogravimetric analysis (TGA) are explored to quantify citrate as one of the most popular hydrophilic ligands on the surface of nanoparticles such as iron oxide nanoparticles (IONPs). The purpose of work is to understand which analytical methods are best suited for surface chemistry analysis of citrate stabilized IONPs and to validate these methods.
T2 - SALSA Make and Measure 2024: Interfaces
CY - Berlin, Germany
DA - 11.09.2024
KW - Nano
KW - Particle
KW - Iron oxide
KW - Ligand
KW - Quantification
KW - Advanced material
KW - Surface analysis
KW - Functional group
PY - 2024
AN - OPUS4-62310
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Meyerhofer, F.
A1 - Dissinger, F.
A1 - Weigert, Florian
A1 - Jungclaus, J.
A1 - Müller-Caspary, K.
A1 - Waldvogel, S. R.
A1 - Resch-Genger, Ute
A1 - Voss, T.
T1 - Citric Acid Based Carbon Dots with Amine Type Stabilizers: pHSpecific
N2 - We report the synthesis and spectroscopic characteristics of two different sets of carbon dots (CDs) formed by hydrothermal reaction between citric acid and polyethylenimine (PEI) or 2,3-diaminopyridine (DAP). Although the formation of amide-based species and the presence of citrazinic acid type derivates assumed to be responsible for a blue emission is confirmed for both CDs by elemental analysis, infrared spectroscopy, and mass spectrometry, a higher abundance of sp2-hybridized nitrogen is observed for DAP-based CDs, which causes a red-shift of the n-π* absorption band relative to the one of PEI-based CDs. These CD Systems possess high photoluminescence quantum yields (QY) of ∼40% and ∼48% at neutral pH, demonstrating a possible tuning of the optical properties by the amine precursor. pH-Dependent spectroscopic studies revealed a drop in QY to < 9% (pH ∼ 1) and < 21% (pH ∼ 12) for both types of CDs under acidic and basic conditions. In contrast, significant differences in the pHdependency of the n-π* transitions are found for both CD types which are ascribed to different (de)protonation sequences of the CD-specific fluorophores and functional groups using Zeta potential analysis.
KW - Fluorescence
KW - Particle
KW - Nano
KW - Surface group analysis
KW - Carbon dot
KW - C-dot
KW - Fluorescent probe
KW - Quantum yield
KW - Synthesis
KW - IR
KW - MS
KW - Polymer
KW - Ligand
PY - 2020
DO - https://doi.org/10.1021/acs.jpcc.9b11732
VL - 124
IS - 16
SP - 8894
EP - 8904
PB - American Chemical Society
AN - OPUS4-50813
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 - CONF
A1 - Oskoei, Parastu
T1 - Thermoresponsive UCNP@MSN Nanoparticles for Doxorubicin Delivery in Melanoma Cells
N2 - Upconversion nanoparticles (UCNPs) possess unique photophysical characteristics, such as excita bility by near infrared (NIR) light, which facilitates deep tissue penetration, multi color emission , long luminescence lifetimes, and an excellent photostability. These features have made UCNPs promising tools for biomedical applications . M esoporous silica nanoparticles (MSNs) functionalized with stimuli responsive nanovalves or specific coatings enable the encapsulation and controlled release of therapeutic agen ts, thereby offering spatiotemporal precision in drug delivery 1 3 ]]. Among drug delivery strategies, photoresponsive systems have attracted growing attention due to their potential for clinical applications . This is especially relevant for melanoma, an aggressive skin cancer with increasing global incidence, for which conventional therapeutic modalities remain largely insufficient in advanced stage 4 In this work, core shell UCNP@MSN nanoparticles were synthetised by coating UCNPs with a mesoporous silica layer, which was subsequently functionalized with thermoresponsive retro Diels Alder nanovalves [ and loaded with the chemotherapeutic agent doxorubicin (DOX). Controlled drug release was effectively achieved under 980 nm NIR i llumination . Treatment with functionalized nanoparticles significantly reduced the viability of melanoma cell lines, with an enhanced cytotoxicity being observed upon combined nanoparticle exposure and NIR illumination . Mechanistic analyses revealed that neither UCNPs nor NIR i llumination alone could induce the production of reactive oxygen species (ROS); however, their combination induced a marked increase in ROS levels in two of the three tested cell lines. Furthermore, this dual treatment promoted substantial apoptotic and/or necrotic responses across all cell models. These findings underscore the potential of UCNP@MSN nanoplatforms, equipped with thermoresponsive ga tes , as efficient photoactivated drug delivery systems for melanoma therapy.
T2 - Conference Jornadas CICECO
CY - Aveiro, Portugal
DA - 09.10.2025
KW - Nano
KW - Particle
KW - Lanthanide
KW - Upconversion
KW - Surface chemistry
KW - Mesoporous silica
KW - Doxorubicin
KW - Nanomedicine
KW - Triggered release
KW - pH
KW - Cellular uptake
KW - Toxicity
KW - Folate
KW - Ligand
PY - 2025
AN - OPUS4-64371
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Quantifying the total and accessible amount of surface functionalities and ligands on nanomaterials
N2 - Engineered nanomaterials (NMs) of various chemical composition and surface functionalization are routinely fabricated for industrial applications such as medical diagnostics, drug delivery, sensing, catalysis, energy conversion and storage, opto-electronics, and information storage. NM dispersibility, stability, processability, and function as well as the interaction with biological species and environmental fate are largely determined by NM surface functionalities, i.e., functional groups (FGs) and ligands. Therefore, reliable, reproducible, and eventually standardized surface characterization methods are vital for quality control of NMs, and mandatory to meet increasing concerns regarding their safety.
Suitable methods for determining surface functionalities on ligand-stabilized core and core/shell NPs include advanced techniques such as traceable quantitative nuclear magnetic resonance (qNMR) as well as X-ray electron spectroscopy (XPS) and time of flight secondary ion mass spectrometry (ToF-SIMS), and simpler optical and electrochemical methods.[1] The latter less costly and fast methods, which can be automated, are often used by NM producers for process and quality control.[1,2] To validate methods, establish measurement uncertain-ties, test reference materials, and produce reference data, multi-method characterization studies are needed.[3,4] as well as interlaboratory comparisons (ILC) on determining NM surface chemistry and well characterized test and reference NMs providing benchmark values.[5,6] Here, we present examples for quantifying common surface FGs such as amino and carboxyl groups on functional NMs of different chemical composition such as silica, polymer, iron oxide, and lanthanide-based upconversion nanoparticles with optical assays, electrochemical titration methods, qNMR, and chromatographic separation techniques. In addition, ongoing interlaboratory comparisons will be presented.
T2 - Yucomat 2025
CY - Herec Novi, Montenegro
DA - 01.09.2025
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Synthesis
KW - Characterization
KW - Advanced material
KW - Surface
KW - Standardization
KW - Reference material
KW - Functional group
KW - Quantification
KW - Coating
KW - Interlaboratory comparison
KW - Uncertainty
PY - 2025
AN - OPUS4-64182
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Measurements of Photoluminescence Quantum Yields of Scattering LED Converter Materials
N2 - How to Get it Right with the Absolute Measurement of Photoluminescence Quantum Yields of Scattering LED Converter Materials Saskia Fiedler+,a, Florian Frenzel+,a, Christian Würth a, Isabella Tavernaro a, Michelle Grüne c, Stefan Schweizer c,d, Axel Engel e, and Ute Resch-Genger a* a Division Biophotonics, Federal Institute for Materials Research and Testing (BAM), Richard-Willstaetter-Strasse 11, D-12489 Berlin, Germany; email: ute.resch@bam.de b Present address: Photonic Materials, NWO-Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands c Faculty of Electrical Engineering, South Westphalia University of Applied Sciences, Lübecker Ring 2, 59494, Soest, Germany d Fraunhofer Application Center for Inorganic Phosphors, Branch Lab of Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Lübecker Ring 2, 59494, Soest, Germany e Schott AG Technical Services, Hattenbergstrasse 10, D-55122 Mainz, Germany Optical measurements of scattering materials such as luminescent nano- and microparticles and phosphors dispersed in liquid and solid matrices play an important role in energy conversion, solid-state lighting, medical diagnostics, and security barcoding. A key performance parameter is the photoluminescence quantum yield QY, i.e., the number of emitted per number of absorbed photons. QY of transparent luminophore solutions can be obtained relative to a fluorescence QY standard of known QY, meanwhile available as certified reference materials.[1] The determination of QY of scattering liquid and solid samples like nanoparticle dispersions, phosphors, and optoceramics requires, however, absolute measurements with an integrating sphere setup. Despite the need for reliable absolute QY measurements, no interlaboratory comparison (ILCs) on measurement uncertainties has been performed and scattering standards with known QY are not available. We present the results of an ILC of 3 labs from academia and industry on measurements of transparent and scattering dye solutions and solid phosphors and converter materials like YAG:Ce optoceramics with commercial stand-alone integrating sphere setups of different illumination and detection geometries. Special emphasis was dedicated to the influence of measurement geometry, optical properties of the blank for determining the number of incident photons absorbed by the sample, and sample-specific surface roughness. Matching QY values could be obtained for transparent dye solutions and scattering dispersions with a blank with scattering properties closely matching those of the sample, QY measurements of optoceramic samples with different blanks revealed substantial differences of more than 20 %. Based on our data, we recommend non-absorbing blank materials with a high reflectivity (>95 %) such as a 2 mm-thick PTFE target placed on the sample holder as blanks.
T2 - eMRS
CY - Strasbourg, France
DA - 26.05.2025
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Quantum yield
KW - NIR
KW - Characterization
KW - Electron microscopy
KW - Film
KW - Integrating sphere spectroscopy
KW - Calibration
KW - Lifetime
KW - Advanced materials
KW - LED converter
KW - YAG:Ce
KW - ILC
KW - Measurement uncertainty
KW - Absolute quantum yield
PY - 2025
AN - OPUS4-63327
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Tavernaro, Isabella
T1 - Development of multimodal methods to quantify the total and accessible number of functional groups and ligands on nanomaterials
N2 - Engineered and tailored nanomaterials (NM) are of great interest in the life and material sciences, as they can be used, e.g., as drug carriers, barcodes, fluorescent sensors, and multimodal labels in bioanalytical assays and imaging applications. Their performance and safety depend not only on their particle size, size distribution, and morphology, but also on their surface chemistry, i.e., the total number of surface functional groups (FG) and the number of FG accessible for subsequent functionalization with ligands or biomolecules, which in turn determines surface charge, colloidal stability, biocompatibility, and toxicity. It also underlines the importance of validated analytical methods that provide accurate information on these application-relevant physicochemical properties with a known uncertainty. In the case of FG quantification, this calls for robust, fast, inexpensive, and reliable methods which allow for the characterization of a broad variety of NM differing in size, chemical composition, and optical properties.
Methods
Aiming at the development of simple, versatile, and multimodal tools for the quantification of bioanalytically relevant FG such as amine, carboxy, thiol, and aldehyde functionalities, we investigated and compared various analytical methods commonly used for FG quantification. This includes electrochemical titration methods, dye-based optical assays, and other instrumental analytical techniques such as nuclear magnetic resonance (NMR), mass spectrometry (MS), and thermal analysis methods.
Results
Here, we will present examples for different types of NMs and FGs including results from a currently running interlaboratory comparison (ILC) with the National Research Council of Canada (NRC) to pave the road for method standardization.
Innovative aspects
• Surface analysis
• Performance and safety of nanomaterials
• Standardization
T2 - ANAKON 2023
CY - Vienna, Austria
DA - 11.04.2023
KW - Engineered Nanomaterials
KW - Surface group analysis
KW - Optical spectroscopy
KW - Quantitative NMR
KW - Ligands
KW - Dye
KW - Particle synthesis
KW - Optical Assays
KW - Titration
KW - Safe-by-Design
KW - Nano
KW - Nanosafety
KW - Silica- and Polystyrene Particles
PY - 2023
AN - OPUS4-59127
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rezvani, A.
A1 - Wang, Z.
A1 - Wegner, Karl David
A1 - Soltanmoradi, H.
A1 - Kichigin, A.
A1 - Zhou, X.
A1 - Gantenberg, T.
A1 - Schram, J.
A1 - Zubiri, B. A.
A1 - Spiecker, E.
A1 - Walter, J.
A1 - Resch-Genger, Ute
A1 - Segets, D.
T1 - Separation of Indium Phosphide/Zinc Sulfide Core−Shell Quantum Dots from Shelling Byproducts through Multistep Agglomeration
N2 - Semiconductor quantum dots (QDs) possess unique electronic and optical properties, making them promising candidates for applications in lightemitting diodes, solar cells, bioimaging, and photocatalysis. Precise control over their size, shape, and chemical and electronic structure is crucial to ensure the desired functional properties and optimize device performance. However, challenges in QD synthesis and post-synthesis modification persist, especially in large-scale production. This study addresses the classification of QDs synthesized in a tubular flow reactor consisting of a mixture of the desired InP/ZnS core−shell QDs and QDs made from the shell material, i.e., here ZnS QDs formed as a byproduct during the formation step of the ZnS shell. The homogeneous nucleation of ZnS nanoparticles from the shelling material introduces a heterogeneity in size and composition and affects the optical properties of the resulting QDs. To address this issue, we developed a size-selective agglomeration (SSA) technique by incrementally introducing ethanol as a poor solvent and classified the synthesized QDs into 13 distinct fractions. These 13 fractions are sorted into three distinct groups: (i) larger InP/ZnS QDs, (ii) a combination of smaller InP/ZnS QDs and larger ZnS QDs, and (iii) predominant ZnS QDs with some very tiny InP/ZnS QDs. The comprehensive characterization of the fractions was conducted using UV−visible absorption spectroscopy, photoluminescence spectroscopy, high-resolution scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, total reflection X-ray fluorescence, and analytical ultracentrifugation. We could demonstrate that our method effectively separated unwanted ZnS QDs from the target InP/ZnS QDs. In addition, the fractions enriched in smaller InP/ZnS QDs exhibited a higher photoluminescence quantum yield compared to the fractions with larger QDs. This demonstrates the efficacy of SSA in finetuning the composition of QD mixtures produced on a larger scale to improve their functional properties. This approach provides fundamental understanding toward the development of a scalable two-dimensional classification process for such ultrasmall nanoparticles by particle size and composition.
KW - Quality assurance
KW - Reference material
KW - Nano
KW - Particle
KW - Quantum dot
KW - Synthesis
KW - Flow reactor
KW - InP
KW - Shell
KW - ZnS
KW - Surface chemistry
KW - Method
KW - Fluorescence
KW - Quantum yield
KW - TEM
PY - 2025
DO - https://doi.org/10.1021/acsnano.4c18530
SN - 1936-086X
VL - 19
IS - 20
SP - 19080
EP - 19094
PB - ACS Publications
AN - OPUS4-63215
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Oskoei, Párástu
T1 - Cell mechanisms induced by doxorubicin-loaded UCNP@MSN nanoparticles with a thermosresponsive nanovalve in melanoma cells
N2 - Upconversion nanoparticles (UCNPs) exhibit several remarkable optical properties, including excitation by near infrared (NIR) light, which enables deep tissue penetration, multiple distinct emission bands across a wide range of wavelengths, long luminescen ce lifetimes, and high photostability. These features make them particularly attractive for various biomedical applications. Mesoporous silica nanoparticles (MSNs), functionalized with nanovalves or specific coatings, have been explored for controlled and targeted drug delivery, where therapeutic agents are encapsulated within the nanopores, allowing spatiotemporal release 1 3 ]]. Among the promising approaches, photoactivated drug delivery systems have drawn considerable interest due to their versatility and potential. One relevant application is in the treatment of melanoma, an aggressive form of skin cancer with a rising global incidence. In advanced stages, conventional therapies often fail to achieve complete tumour eradication, resulting in poor prognose s 4 In this study, UCNPs were coated with a mesoporous silica shell to form core shell UCNP@MSN nanoparticles, which were further functionalized with thermoresponsive retro Diels Alder nanovalves and loaded with doxorubicin (DOX), a chemotherapeutic drug used in melanoma treatment. Upon exposure to 980 nm NIR light, DOX release was successfully triggered in the culture medium. Exposure to functionalized UCNPs decreased the viability of the tested melanoma cell lines, with further reductions observed when the ex posure to the nanoparticles was combined with irradiation. Subsequently, t he toxicity mechanisms were evaluated and showed that w hile individual treatments with either the functionalized UCNPs or NIR irradiation alone had no effect on reactive oxygen species (ROS) production, their combination significantly increased ROS levels in two of the three tested cell lines. This combined treatment also led to notable increases in apoptotic , necrotic or both type of cells’ percentages on all cell lines. Overall, these findings highlight the potential of these nanoparticles with thermoresponsive gating mechanisms as effective platforms for targeted drug delivery in melanoma therapy.
T2 - EUROTOX 2025
CY - Athens, Greece
DA - 14.09.2025
KW - Nano
KW - Particle
KW - Lanthanide
KW - Upconversion
KW - Surface chemistry
KW - Mesoporous silica
KW - Doxorubicin
KW - Nanomedicine
KW - Triggered release
KW - pH
KW - Cellular uptake
KW - Toxicity
KW - Folate
KW - Ligand
PY - 2025
AN - OPUS4-64372
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Forschung in einer Bundesoberbehörde wie der BAM
N2 - Die Bundesanstalt für Materialforschung und -prüfung (BAM) ist eine forschende Bundesoberbehörde und Einrichtung der Ressortforschung der Bundesrepublik Deutschland. Unter ihrer Leitlinie „Sicherheit in Technik und Chemie“ ist sie zuständig für die öffentliche technische Sicherheit und für metrologische Aufgaben in der Chemie. Das Aufgabenspektrum der BAM, das sich an aktuellen Fragestellungen aus Wissenschaft, Wirtschaft, Politik und Normung orientiert, bietet sehr viele interessante Tätigkeitsfelder für Naturwissenschaftler*Innen und Ingenieur*Innen.
T2 - WIFO Leipzig 2023
CY - Leipzig, Germany
DA - 05.09.2023
KW - Quality assurance
KW - Optical spectroscopy
KW - Certification
KW - Reference product
KW - Integrating sphere spectroscopy
KW - Fluorescence
KW - Quantum yield
KW - Reference material
KW - Reference data
KW - Traceability
KW - Nano
KW - Particle
KW - Analytical chemistry
KW - Sensor
KW - Safety
PY - 2023
AN - OPUS4-58397
LA - mul
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Matiushkina, Anna
T1 - Quantification of Hydrophilic Surface Ligands on Nanoparticles
N2 - The rapid development of nanotechnology is driven by a wide range of possible applications of nanoparticles (NPs) depending on their functions and composition, for example, in biomedicine, energy harvesting, and optoelectronics. Due to the large surface-to-volume ratio of nanoparticles, their properties and function are often highly dependent on surface chemistry, which also determines their stability and interaction with the environment. To ensure the successful advancement of nanomaterials in biomedical applications as well as in material sciences, it is hence crucial to develop reliable methods to control and quantify ligand molecules and functional groups on the NP surface for different NP processing steps including ligand exchange and the subsequent functionalization with, e.g., antifouling agents and recognition moieties. These methods must then be validated and eventually standardized. This also calls for suitable reference materials with known surface chemistries or functionalities.
Methods for determining and quantifying surface functional groups and NP capping ligands include quantitative nuclear magnetic resonance (qNMR) techniques, thermogravimetric analysis (TGA), mass spectrometric (MS) methods, high-performance liquid chromatography (HPLC), and optical assays with photometric and/or fluorometric readout.[1] In the focus of this study on ligand exchange and quantification are differently sized iron oxide nanoparticles (IONPs), already used in biomedicine with applications as magnetic resonance imaging (MRI) contrast agents or for magnetic hyperthermia. IONPs can be prepared by a high temperature synthesis in nonpolar solvents, resulting in a superior monodispersity and crystallinity compared to particles prepared by aqueous synthesis methods. Such IONPs bear, however, hydrophobic surface ligands, that need to be exchanged for hydrophilic molecules to ensure water dispersibility required for biomedical applications. For these applications, a complete removal of potentially toxic surface ligands remaining from IONP synthesis is crucial. Here, we will present the synthesis of differently sized spherical IONPs capped with hydrophobic oleic acid molecules and an in-depth study of the ligand exchange to hydrophilic molecules such as citrate. We assessed the size, size distribution, and colloidal stability of the IONPs utilizing transmission electron microscopy (TEM), dynamic light scattering (DLS), and Zeta potential measurements before and after ligand exchange. In addition, several approaches to ligand quantification have been explored involving a variety of analytical tools. Our ultimate goal is here to identify the optimal methods for ligand analysis and to develop schemes for method validation, via the comparison of analytical techniques relying on different principles of signal generation (method cross-validation).
T2 - E-MRS 2024 SPRING MEETING
CY - Strasbourg, France
DA - 27.05.2024
KW - Nano
KW - Particle
KW - Iron oxide
KW - Ligand
KW - Quantification
KW - Advanced material
KW - Surface analysis
KW - Functional group
PY - 2024
AN - OPUS4-62296
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Oskoei, Párástu
T1 - Effects of upconversion nanoparticles with a thermo-responsive nanovalve loaded with doxorubicin in melanoma cells
N2 - Melanoma skin cancer has an increasingly higher incidence , and w hen detected in advanced stages, tumour eradication is often incomplete, contributing to poor prognosis with conventional treatments. Upconversion nanoparticles (UCNPs) have unique properties, such as excitability under near infrared (NIR) excitation light, which confers a relatively high penetration depth in tissue that allow their effective use in several biomedical applications Mesoporous silica nanoparticles (MSN) with nanovalves or derived coatings have widely been used for triggered and targeted drug delivery in the past. Anticancer drugs can be loaded into the pores of MSN, enabling controlled drug release. In this work, UCNPs were coated with a mesoporous silica shell yielding UCNP@MSN core shell nanoparticles which were equipped with thermoresponsive retro Diels Alder nanovalves and then loaded with DOX , a chemotherapeutic agent for melanoma treatmen t (UCNP@MSN DOX) Subsequent DOX release from this drug delivery system was triggered by 980 nm NIR light. Melanoma cells exposed to UCNP@MSN DOX or the NIR laser exhibited no change in ROS production , while the combination of both induced an increase in ROS production. This combination of conditions also induced changes on apoptosis and necrosis levels. These findings underscore the potential use of UCNP @MSN drug delivery systems with thermoresponsive caps as effective drug delivery platforms for melanoma therapy.
T2 - VII iBiMED Symposium
CY - Aveiro, Portugal
DA - 23.05.2025
KW - Nano
KW - Particle
KW - Lanthanide
KW - Upconversion
KW - Surface chemistry
KW - Mesoporous silica
KW - Doxorubicin
KW - Nanomedicine
KW - Triggered release
KW - pH
KW - Cellular uptake
KW - Toxicity
KW - Folate
KW - Ligand
PY - 2025
AN - OPUS4-64373
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ramirez, Alejandra
A1 - Pauli, Jutta
A1 - Crasselt, C.
A1 - Simon, S.
A1 - Schmidt, W.
A1 - Resch-Genger, Ute
T1 - The effect of a polycarboxylate ether on C3A / CaSO4.2H2O passivation monitored by optical spectroscopy
N2 - Polycarboxylate ethers (PCEs) are widely used in construction, but the exact nature of their interaction with cement is still debated. Aiming at a better understanding of the role of tricalcium Aluminate (C3A) in cement hydration, we assessed the potential of optical spectroscopy in combination with a water-soluble fluorescent organic reporter dye (S0586) to monitor the early hydration of C3A in the presence of 26 wt% CaSO4.2H2O (C3A26G-S) with and without PCE. As optical methods, steady-state fluorescence and diffuse reflectance (UV–VisDR) spectroscopy were employed. Phase characterization and particle size distribution were performed with in-situ X-ray diffraction (in-situ XRD) and dynamic light scattering (DLS). Our results show that fluorescence and UV–VisDR spectroscopy can be used to monitor the formation of metastable phases by the disaggregation of the dye S0586 in a cement paste as well as changes in ettringite formation. Addition of PCE slowed down the disaggregation of the dye as reflected by the corresponding changes of the dyes absorption and fluorescence. This prolonged induction period is a well-known side effect of PCEs and agrees with previous reported calorimetric studies and the Inhibition of gypsum dissolution observed by in-situ XRD. This demonstrates that fluorescence and UV–VisDR spectroscopy together with a suitable optical probe can provide deeper insights into the influence of PCE on C3A-gypsum hydration which could be e.g., utilized as screening method for comparing the influences
of different types of PCEs.
KW - Fluorescence
KW - Cement
KW - Nano
KW - Particle
KW - Optical spectroscopy
KW - PCE
KW - XRD
KW - Calorimetry
KW - Monitoring
KW - Diffuse
KW - Reflection
KW - Phase
KW - Dye
KW - Optical probe
KW - Cyanine
KW - Sensor
KW - Method
KW - Analysis
PY - 2020
DO - https://doi.org/10.1016/j.conbuildmat.2020.121856
VL - 270
SP - 121856
PB - Elsevier Ltd.
AN - OPUS4-52118
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Andreato, E.
A1 - Panov, N.
A1 - Artiga, A.
A1 - Osipova, Viktoriia
A1 - Resch-Genger, Ute
A1 - Ximendes, E.
A1 - Molina, P.
A1 - Canton, P.
A1 - Marin, R.
T1 - Indium-Based Fluoride Nanoparticles Doped with Chromium for Near-Infrared Luminescence
N2 - Transition metal (TM) and rare earth (RE) ion-doped nanoparticles (NPs) are photoluminescent materials of technological relevance in bioimaging, sensing, and light conversion. Fluoride NPs are particularly attractive in this context, since they combine low-energy phonons, high chemical stability, optical transparency, size, and architecture tunability. Yet, nearly all reported colloidal fluoride NPs (e.g., NaYF4 and LiYF4) can only be efficiently doped with RE3+ and not with luminescent TM ions. Herein, we contribute to filling this gap in materials science by reporting Na3InF6 NPs doped with Cr3+ as a model luminescent TM ion. We unveil the heat-driven NP formation mechanism, which involves a cubic-to-monoclinic phase conversion, similarly to the cubic-tohexagonal phase conversion in NaYF4. Reaction temperatures above 225 °C and reaction time have a limited impact on the NP morphology, while the amount of fluoride precursor and oleylamine grants control over the NP size. After verifying that Na3InF6 NPs show negligible cytotoxicity toward U-87 cell line, we study the optical properties of these NPs upon Cr3+ doping.
Temperature-dependent photoluminescence measurements indicate that Cr3+ ions experience a weak crystal field in the Na3InF6 host lattice, while their photoluminescence lifetime varies linearly in the 20−50 °C range. These results set the ground for further studies of photoluminescent TM-doped fluoride NPs, toward their applications in bioimaging, sensing, and light-converting devices.
KW - Quality assurance
KW - Fluorescence
KW - Traceability
KW - Nano
KW - Particle
KW - Synthesis
KW - Quantum yield
KW - NIR
KW - Mechanism
KW - Characterization
KW - XRD
KW - Phase transition
KW - Ligand
KW - Surface
KW - Doping
KW - Lifetime
PY - 2025
DO - https://doi.org/10.1021/acs.chemmater.4c03335
SN - 1520-5002
SP - 1
EP - 14
PB - American Chemical Society
AN - OPUS4-63073
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Matiushkina, Anna
T1 - Quantification of Citrate Ligands on Nanoparticle Surfaces
N2 - To ensure the successful advancement of nanomaterials (NM) in applications and their safe use, it is crucial to develop reliable methods to control and quantify ligands and functional groups (FG) on the nanoparticle (NP) surface as surface chemistry largely determines the interactions of NPs with their surroundings. Many analytical methods can be used for this purpose. However, their applicability strongly depends on the type of NM and ligand(s) and most of them require challenging protocols for sample preparation, i.e., the removal of the NPs or their dissolution, which can influence the accuracy of the measurements. While some methods allow the precise quantification of specific ligands such as quantitative nuclear magnetic resonance (qNMR), others provide only semi-quantitative results like Fourier Transform infrared spectroscopy (FTIR) or target more general analyte groups like thermogravimetric analysis (TGA) detecting mass losses (total organic content) or conductometry (e.g., (de)protonable FGs such as carboxyl or amine groups). [1] The calculation of the coverage of the NP surface with ligands, additionally requires knowledge of their total surface area, which can be obtained, e.g., from a precise characterization of NP size and concentration.
Citrate is one of the most frequently utilized surface ligand for stabilizing metal, metal oxide, and lanthanide-based upconversion NPs in hydrophilic environments. However, its quantification on NP surfaces has rarely been addressed although it is a frequent analyte in medical or food analysis. In this study we compare several methods for quantifying citrate as capping ligands of iron oxide NPs (IONPs), exemplarily chosen because of their broad applications in the life science. [2] The size of the IONPs was characterized by electron microscopy (EM) and dynamic light scattering (DLS), while their concentration was determined by quantifying iron ions after acidic particle dissolution using a colorimetric assay and inductively coupled plasma optical emission spectroscopy (ICP-OES). The simplest approach for citrate quantification, direct photometric UV-detection after acidic digestion of the IONPs, yielded only reasonable results when combined with reversed phase high-performance liquid chromatography (HPLC). These results were cross validated with qNMR that required the development of a reliable sample preparation protocol addressing not only particle dissolution in deuterated solvents but also the removal of the paramagnetic iron ions interfering with NMR measurements. Comparison with results from TGA gives insight into the sensitivity and specificity of these methods and their potential for quantifying surface ligands on NPs.
T2 - Anakon 2025
CY - Leipzig, Germany
DA - 10.03.2025
KW - Advanced material
KW - Functional group
KW - Iron oxide
KW - Ligand
KW - Nano
KW - Particle
KW - Quantification
KW - Surface analysis
PY - 2025
AN - OPUS4-64861
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Homann, Christian
A1 - Peeters, Régis
A1 - Mirmajidi, Hana
A1 - Berg, Jessica
A1 - Fay, Michael
A1 - Rodrigues, Lucas Carvalho Veloso
A1 - Radicchi, Eros
A1 - Jain, Akhil
A1 - Speghini, Adolfo
A1 - Hemmer, Eva
T1 - Rapid microwave-assisted synthesis of morphology-controlled luminescent lanthanide-doped Gd2O2S nanostructures
N2 - Gadolinium oxysulfide (Gd2O2S) is an attractive material of demonstrated suitability for a variety of imaging applications, leveraging its magnetic, scintillating, and luminescent properties, particularly when doped with optically active lanthanide ions (Ln3+). For many of these applications, control over size and morphology at the nanoscale is crucial. This study demonstrates the rapid microwave-assisted Synthesis of colloidal Ln2O2S (Ln = Gd and dopants Yb, Er, Tb) nanostructures in as little as 20 min. Structural characterization using X-ray diffraction analysis (XRD), Raman spectroscopy, as well as Transmission electron microscopy (TEM), including elemental mapping via energy dispersive X-ray spectroscopy (EDS), unveiled the key role of elemental sulphur (S8) in the reaction mixtures for materials growth. By systematically varying the Ln-to-S ratio from 1 : 0.5 to 1 : 15, controlled morphologies ranging from triangular nanoplatelets to berry- and flower-like shapes were achieved. Doping with Er3+/Yb3+ endowed the nano-triangles with upconverting and near-infrared emitting properties. Tb3+-doped Gd2O2S exhibited the characteristic green Tb3+ emission under UV excitation, while also showing X-ray excited optical luminescence (XEOL), rendering the material interesting as a potential nano-scintillator.
KW - Upconversion
KW - Microwave-assisted synthesis
KW - Synthesis
KW - Fluorescence
KW - Nano
KW - Particle
KW - NIR
KW - XRD
KW - X-ray fluoressence
KW - Morphology control
KW - Raman
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647907
DO - https://doi.org/10.1039/D5TC01646K
SN - 2050-7526
VL - 13
IS - 35
SP - 18492
EP - 18507
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-64790
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 - CONF
A1 - Resch-Genger, Ute
A1 - Würth, Christian
A1 - Frenzel, Florian
A1 - Weigert, Florian
A1 - Andresen, Elina
A1 - Grauel, Bettina
A1 - Wegner, Karl David
T1 - Semiconductor (SCNC) & Upconversion Nanocrystals (UCNC) – Optical Properties, Applications & Challenges
N2 - Inorganic nanocrystals with linear and nonlinear luminescence in the ultraviolet, visible, near infrared and shortwave infrared like semiconductor quantum dots and spectrally shifting lanthanide-based nanophosphors have meanwhile found applications in the life and material sciences ranging from optical reporters for bioimaging and sensing over security barcodes to solid state lighting and photovoltaics. These nanomaterials commonly have increasingly sophisticated core/shell particle architectures with shells of different chemical composition and thickness to minimize radiationless deactivation at the particle surface that is usually the main energy loss mechanism [1]. For lanthanide-based spectral shifters, particularly for very small nanoparticles, also surface coatings are needed which protect near-surface lanthanide ions from luminescence quenching by high energy vibrators like O-H groups and prevent the disintegration of these nanoparticles under high dilution conditions. [2,3,4]. The identification of optimum particle structures requires quantitative spectroscopic studies focusing on the key performance parameter photoluminescence quantum yield [5,6], ideally flanked by single particle studies to assess spectroscopic inhomogeneities on a particle-to-particle level for typical preparation methods [7], Moreover, in the case of upconversion nanoparticles with a multi-photonic and hence, excitation power density (P)-dependent luminescence, quantitative luminescence studies over a broad P range are required to identify particle architectures that are best suited for applications in fluorescence assays up to fluorescence microscopy. Here, we present methods to quantify the photoluminescence of these different types of emitters in the vis/NIR/SWIR and as function of Pand demonstrate the importance of such measurements for a profound mechanistic understanding of the nonradiative deactivation pathways in semiconductor and upconversion nanocrystals of different size and particle architecture in different environments.
T2 - 27th Annual Meeting of the Slovenian Chemical Society
CY - Portoroz-Portorose, Slovenia
DA - 21.09.2021
KW - Nano
KW - Nanomaterial
KW - Upconversion nanoparticle
KW - Lanthanide
KW - Photoluminescence
KW - Quantum yield
KW - Photophysics
KW - Lifetime
KW - Surface chemistry
KW - Single particle
KW - Brightness
KW - NIR
KW - Synthesis
KW - Semiconductur
KW - Quantum dot
KW - Nanocrystal
KW - SWIR
PY - 2021
AN - OPUS4-53723
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Resch-Genger, Ute
T1 - Tumore abbilden, Biomarker nachweisen, Messungen standardisieren
N2 - Zu den am häufigsten eingesetzten Analysemethoden in den Lebens- und Materialwissenschaften gehören Lumineszenzmethoden. Sie nutzen die Emission von Licht nach Absorption von Energie, um Signale zu erzeugen, und umfassen spektroskopische und mikroskopische Messungen.
KW - Quality assurance
KW - Sensor
KW - Imaging
KW - Reference material
KW - Nano
KW - Particle
KW - Nanomaterial
KW - Upconversion
KW - Nanoparticle
KW - Lanthanide
KW - Photoluminescence
KW - Quantum yield
KW - Photophysics
KW - Lifetime
KW - Excitation
KW - Power density
KW - Single particle
KW - Brightness
KW - NIR
PY - 2021
SP - 75
EP - 77
PB - GDCH
AN - OPUS4-53526
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Pauli, Jutta
A1 - Würth, Christian
A1 - Güttler, Arne
A1 - Resch-Genger, Ute
T1 - Reliable Determination of the Signal-Relevant Spectroscopic Key Characteristics of Luminescent Reporters and Optical Probes for Imaging in the vis/NIR/SWIR
N2 - Introduction. Comparing different emitter classes and rationally designing the next generation of molecular and nanoscale probes for bioimaging applications require accurate and quantitative methods for the measurement of the key parameter photoluminescence quantum yield f.1 f equals the number of emitted per number of absorbed photons. This is particularly relevant for increasingly used fluorescence imaging in the short wave-infrared region (SWIR) ≥ 900 nm providing deeper penetration depths, a better image resolution, and an improved signal-to-noise or tumor-to-background ratio.2, 3 However, spectroscopic measurements in the SWIR are more challenging and require specific calibrations and standards.
T2 - EMIM 2021
CY - Göttingen, Germany
DA - 24.08.2021
KW - Fluorescence
KW - Optical probe
KW - Dye
KW - Photophysics
KW - Quantum yield
KW - Mechanism
KW - NIR
KW - SWIR
KW - Imaging
KW - Reference material
KW - Reliability
KW - Nano
KW - Particle
KW - Method
KW - Quality assurance
PY - 2021
AN - OPUS4-53233
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Design and Quantitative Characterization of Functional Molecular Chromophores and Nanomaterials with UV/vis/NIR/IR Emission – An Overview of Research Activities in Division Biophotonics
N2 - In the focus of division Biophotonics are the design, preparation, analytical and spectroscopic characterization, and application of molecular and nanoscale
functional materials, particularly materials with a photoluminescence in the visible, near infrared (NIR) and short-wave infrared (SWIR). This includes optical reporters for bioimaging and sensing, security and authentication barcodes, and materials for solid state lighting, energy conversion, and photovoltaics. For the identification of optimum particle structures quantitative spectroscopic studies are performed under application-relevant conditions, focusing on the key performance parameter photoluminescence quantum yield. In addition, simple, cost-efficient, and standardizable strategies for quantifying functional groups on the surface of nano- and microparticles are developed, here with a focus on optical assays and electrochemical titration methods, cross-validated by more advanced methods such as quantitative NMR. In addition, reference materials and reference products are developed for optical methods, particularly luminescence techniques, and for analytical methods utilized for the characterization of nanomaterials.
T2 - Projekttreffen Nile-Chrome 2.0
CY - Mainz, Germany
DA - 11.12.2023
KW - Fluorescence
KW - Quantum yield
KW - Optical spectroscopy
KW - Reference material
KW - Reference data
KW - Quality assurance
KW - Dye
KW - Reference product
KW - NIR
KW - SWIR
KW - Nano
KW - Particle
KW - Silica
KW - Polymer
KW - Surface group analysis
KW - Sensor molecules
PY - 2023
AN - OPUS4-59123
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Resch-Genger, Ute
ED - Otto, S.
ED - Scholz, Norman
ED - Behnke, Thomas
ED - Heinze, K.
T1 - Thermo-Chromium: A Contactless Optical Molecular Thermometer
N2 - The unparalleled excited-state potential-energy landscape of the chromium(III)-based dye [1]3+ ([Cr(ddpd)2]3+; ddpd=N,N’-dimethyl-N,N’-dipyridin-2-ylpyridin-2,6-diamine) enables a strong dual emission in the near infrared region. The temperature dependence of this dual emission allows the use of [1]3+ as an unprecedented molecular ratiometric thermometer in the 210–373 K temperature range in organic and in aqueous media. Incorporation of [1]3+ in biocompatible nanocarriers, such as 100 nm-sized polystyrene nanoparticles and solutol micelles, provides nanodimensional thermometers operating under physiological conditions.
KW - Temperature
KW - Sensor
KW - Dual emission
KW - Fluorescence
KW - Cr complex
KW - Nano
KW - Particle
KW - Micelle
KW - Probe
KW - Environment
PY - 2017
DO - https://doi.org/10.1002/chem.201701726
SN - 0947-6539
VL - 23
IS - 50
SP - 12131
EP - 12135
PB - Wiley-VCH
AN - OPUS4-42539
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Tavernaro, Isabella
T1 - Design of Fluorescent, Amorphous Silica-NPs and their Versatile Use in Sensing Applications
N2 - Surface functionalized silica nanoparticles (SiO2-NP) gained great interest in the life and material sciences, as they can be used e.g. as drug carriers, fluorescent sensors, and multimodal labels in bioanalytical assays and imaging applications. They are highly stable, are easily produced and modified on a large scale at low cost and can be labeled or stained with a multitude of sensor dyes. These dye modified particle conjugates have several advantages as compared to conventional molecular probes like enhanced brightness, ease of designing ratiometric systems by combining analyte-sensitive and inert reference dyes, and increased photostability. Moreover, stained nanoparticles can enable the use of hydrophobic dyes in aqueous environments.
Here we present our work on multicolored sensors for the measurement of pH, oxygen and saccharides utilizing amorphous SiO2 NPs.
T2 - Focus Area Day Analytical Sciences 2023
CY - Berlin, Germany
DA - 20.04.2023
KW - Amorphous silica particles
KW - Particle Synthesis
KW - Nano
KW - Ratiometric Sensors
KW - Fluorescence
KW - pH probe
KW - Dye
PY - 2023
AN - OPUS4-59151
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Measuring the Upconversion Luminescence of Ensemble and Single Particle Lanthanide-Based Upconversion Nanocrystals
N2 - Lanthanide-based upconversion nanoparticles (UCNPs) like hexagonal 𝛽-NaYF4 UCNPs doped with Yb3+ and Er3+, which efficiently convert 976 nm light to ultraviolet, visible, and near infrared photons, offer new strategies for luminescence-based sensing, barcoding, and Imaging. Their upconversion (UC) luminescence (UCL) features like UCL intensity, quantum yield, relative spectral distribution / UCL luminescence color, and luminescence decay kinetics are, however, strongly influenced by particle size, dopant ion concentration, particle architecture, surface chemistry including presence and thickness of surface passivation and shielding shells, microenvironment/presence of quenchers with high energy vibrations, and excitation power density (P).
We present here a comprehensive study of the influence of excitation power density on the UCL features of different types of UCNPs, focusing on Yb3+ and Er3+ co-doped NaYF4 core-only and core-shell nanostructures with different sizes and doping ion concentration, which underlines the importance of P-dependent optimum dopant concentrations for UCNP performance and the potential of P-tuning of UCL.
T2 - Materials Challenges in Alternative & Renewable Energy 2021 (MCARE 2021)
CY - Online meeting
DA - 19.07.2021
KW - Fluorescence
KW - Lifetime
KW - Method
KW - Stability
KW - Coating
KW - Surface chemistry
KW - Lanthanide
KW - Upconversion
KW - Nano
KW - Particle
KW - Single particle spectroscopy
KW - Quantum yield
KW - Microscopy
KW - Photophysics
PY - 2021
AN - OPUS4-53111
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Andresen, Elina
T1 - Lanthanide based multi element nanoparticles: a versatile platform for surface chemistry analysis and potential reference materials
N2 - The use of engineered nanoparticles of different size, shape, and composition is continuously increasing in the life and materials sciences. This calls for methods and reference materials enabling the reliable and accurate determination of nanoparticle size, particle size distribution, shape, number concentration, degree of aggregation and agglomeration in different environments as well as for nanoparticle dispersibility and stability.
We are currently building up and exploring a platform of lanthanide-based nanocrystals (LnNCs) with application-specifically tuned size, shape, composition, architecture, optical properties, and surface chemistry for emerging applications in life sciences. As a prerequisite for the broad applicability of these nanomaterials, we assess simple, robust, and easily upscaleable synthesis protocols for LnNCs with defined morphologies and tunable optical properties, and the short-term and long-term stability of LnNCs with selected surface coatings in aqueous environments under different application-relevant conditions.
T2 - Anakon 2025
CY - Leipzig, Germany
DA - 10.03.2025
KW - Nano
KW - Particle
KW - Method
KW - Lanthanide
KW - Synthesis
KW - Upconversion
KW - Ligand
KW - Quality assurance
KW - Particle number concentration
KW - Reference material
KW - Surface chemistry
PY - 2025
AN - OPUS4-62768
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Tavernaro, Isabella
T1 - How to Quantify the Total and Accessible Number of Functional Groups and Ligands on Nanomaterials Using a Multimodal Approach – A Bilateral Comparison
N2 - Surface-functionalized organic and inorganic engineered nanomaterials (NM) have gained increasing interest in various fields of application such as nanomedicine, bioimaging and sensing, or as additives in food and consumer products. The performance and safe use of these NM in such applications depend not only on their composition, primary particle size, and morphology, but also on surface chemistry, which controls surface charge, colloidal stability, biocompatibility, and toxicity.[1] NM surface chemistry is mainly determined by the total number of surface functional groups (FG) and the number of FG accessible for subsequent functionalization with ligands or biomolecules. Thus, methods for FG quantification are not only important tools for the control of NM production processes, but can also foster the sustainable development of functional and safe(r) NM. In addition, this need underlines the importance of validated and standardized analytical methods that provide accurate information on application-relevant physicochemical properties with known uncertainties, flanked by suitable quality control samples and reference materials. Aiming at the development of simple, versatile, and multimodal tools for the quantification of common bioanalytically relevant FG, we investigated and compared various analytical methods commonly used for FG quantification.[2,3] The potential of multimodal approaches for FG quantification was recently demonstrated in a bilateral comparison of the surface analysis of commercially available aminated silica nanoparticles (SiO2-NP).[3] These results demonstrate not only an influence of the size and synthesis methods on the number of FG but also on NM performance. This concept is currently explored in a second bilateral comparison of quantitative nuclear magnetic resonance (qNMR) measurements and optical assays for differently sized commercial and in-house synthesized SiO2-NP with varying amounts of amine functionalities, utilizing further optimized protocols for sample preparation, qNMR measurements, and data evaluation. This strategy can contribute to establishing multi-method characterization strategies for NMs and can provide a more detailed picture of structure-properties relationships for different types of functional NM.
T2 - E-MRS Spring Meeting 2024 & ALTECH 2024
CY - Strasbourg, France
DA - 27.05.2024
KW - Quantification
KW - Nano
KW - Particle
KW - Quality assurance
KW - Interlaboratory comparison
KW - Method
KW - Uncertainty
KW - Reference material
KW - Sensors
KW - Synthesis
KW - Silica
KW - Surface analysis
PY - 2024
AN - OPUS4-62161
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zhao, J.
A1 - Hu, Y.
A1 - wei Lin, S.
A1 - Resch-Genger, Ute
A1 - Zhang, R.
A1 - Wen, J.
A1 - Kong, X.
A1 - Qin, A.
A1 - Ou, J.
T1 - Enhanced luminescence intensity of near-infraredsensitized sensitized upconversion nanoparticles via Ca²+ doping for a nitric oxide release platform
N2 - Light-induced NO release based on exogenous NO donors has attracted substantial attention in clinical applications; the induction light source usually converts near-infrared light to blue or ultraviolet light.
However, the low efficiency of near-infrared light-assisted chemical light energy conversion remains a challenge, especially for NaYF4:Yb3+/Tm3+ photoconverting near-infrared light to ultraviolet (UV) and blue light. In this paper, a luminescence-enhanced strategy is reported by doping Ca2+ into NaYF4:Yb3+/Tm3+ and coating it with NaGdF4 through a two-step solvothermal method. Then, UCNPs modified with methyl-b-cyclodextrin (M-b-CD) are loaded on a ruthenium nitrosyl complex [(3)Ru(NO)(Cl)] as nitric oxide release-molecules (NORMs). X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) data demonstrated that Ca2+ was successfully doped into NaYF4:Yb3+/Tm3+ nanoparticles as the core, and a pure hexagonal phase, NaYF4, was obtained from the doping of Ca2+. TEM revealed that the crystallinity was significantly improved after Ca2+ doping, and the core–shell structure was successfully synthesized, with NaGdF4 directionally grown on the NaYF4:Ca/Yb/Tm core. Fluorescence tests showed that, especially in the ultraviolet and blue light excitation wavelength regions, the UC emission intensity of the Ca-doped NaYF4:Yb3+/Tm3+@NaGdF4 core–shell UCNPs increased by 302.95 times vs. NaYF4:Yb3+/Tm3+ UCNPs. Finally, the release of NO was tested by the Griess method. Under 980 nm irradiation, the cell viability distinctly decreased with increasing UCNPs@M-b-CD-NORMs concentration. This study Shows that NORM release of NO is triggered by enhanced up-converted UV and blue light, which can be used for the development of UV photo-sensitive drugs.
KW - Nano
KW - Nanomaterial
KW - Upconversion nanoparticle
KW - Lanthanide
KW - Photoluminescence
KW - Quantum yield
KW - Photophysics
KW - Lifetime
KW - Sensor
KW - Surface chemistry
KW - Single particle
KW - Brightness
KW - NIR
KW - PDT
PY - 2020
DO - https://doi.org/10.1039/d0tb00088d
VL - 8
IS - 30
SP - 6481
EP - 6489
PB - Journal of Materials Chemistry B
AN - OPUS4-51262
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zavoiura, Oleksandr
A1 - Resch-Genger, Ute
A1 - Seitz, Oliver
T1 - Quantum dot-PNA conjugates for target-catalyzed RNA detection
N2 - Detection of pathogenic nucleic acids remains one of the most reliable approaches for the diagnosis of a broad range of diseases. Current PCR-based methods require experienced personnel and cannot be easily used for point-of care diagnostics, making alternative strategies for the sensitive, reliable, and cost-efficient detection of pathogenic nucleic acids highly desirable. Here, we report an enzyme-free method for the fluorometric detection of RNA that relies on a target-induced fluorophore transfer onto a semiconductor quantum dot (QD), uses PNA probes as selective recognition elements and can be read out with simple and inexpensive equipment. For QD-PNA conjugates with optimized PNA content, limits of detection of dengue RNA in the range of 10 pM to 100 nM can be realized within 5 h in the presence of a high excess of noncomplementary RNA.
KW - FRET
KW - Fluorescence
KW - DNA
KW - Assay
KW - Quantum dot
KW - Nano
KW - Particle
KW - Synthesis
KW - Ligation Assay
PY - 2018
DO - https://doi.org/10.1021/acs.bioconjchem.8b00157
SN - 1043-1802
VL - 29
IS - 5
SP - 1690
EP - 1702
PB - ACS Publications
AN - OPUS4-45120
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Osipova, Viktoriia
T1 - Incorporation of near-infrared light emitting chromium (III) complexes into silica nanoparticles and spectroscopic characterization
N2 - In recent years, chromium (III) complexes have received a lot of attention as novel near-infrared (NIR) emitters triggered by the report on the first molecular ruby Cr(ddpd)2(BF4)3 with a high photoluminescence quantum yield of 13.7% of its near infrared (NIR) emission band and a long luminescence lifetime of 1.122 ms at room temperature.[1] However, in an oxygen-containing environment, the photoluminescence quantum yields and luminescence lifetimes of these chromium(III) complexes show only very small values. This hampers their application as NIR luminescence labels. This application, that cannot be tackled by conventional deoxygenating approaches, requires suitable strategies to protect the luminescence of the chromium(III) complexes from oxygen quenching. An elegant approach to reduce the undesired luminescence quenching by triplet oxygen explored by us presents the incorporation of these chromium(III) complexes into different types of amorphous, non-porous silica nanoparticles, that can be simply surface functionalized, e.g., with targeting ligands and/or other sensor molecules. In this work, as first proof-of-concept experiments, a set of chromium (III) complexes constituting of different ligands and counter anions, were embedded into the core of silica nanoparticles. Subsequently, the optical properties of the resulting luminescent silica nanoparticles were spectroscopically assessed by steady state and time-resolved luminescence spectroscopy. First results of time-resolved luminescence measurements confirm our design concept of nanoscale NIR emissive Cr(III) complex-based reporters
T2 - Projekttreffen Nile-Chrome 2.0
CY - Mainz, Germany
DA - 11.12.2023
KW - Cr(III) complex
KW - NIR
KW - Luminescence
KW - Nano
KW - Silica
KW - Lifetime
KW - Quantum Yields
KW - Particle Synthesis
KW - Sensors
KW - Probe
KW - Surface Group Analysis
PY - 2023
AN - OPUS4-59149
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
A1 - Wegner, Karl David
T1 - Luminescent Nanoparticles – From Photophysics to the Measurement of Photoluminescence Quantum Yields
N2 - Inorganic nanocrystals with linear and nonlinear photoluminescence in the ultraviolet, visible, near infrared and short-wave infrared like spectrally shifting lanthanide-based nanoparticles (LnNCs) like NaYF4: Yb, Er and semiconductor quantum dots have meanwhile found applications in the life and material sciences ranging from optical reporters for bioimaging and sensing over security barcodes to solid state lighting and photovoltaics. The identification of optimum particle architectures for photonic applications requires quantitative spectroscopic studies, ideally flanked by single particle studies to assess spectroscopic inhomogeneities on a particle-to-particle level for typical preparation methods. In the following, photoluminescence studies of LnNCs are presented, addressing parameters such as particle size, surface coating, and dopant ion concentration as well as excitation power density mandatory for a profound mechanistic understanding of the nonradiative deactivation pathways in these nanocrystals. In addition, methods for the determination of particle brightness and photoluminescence quantum yield in different spectral windows are presented.
T2 - Phoenix Colloquium
CY - Hannover, Germany
DA - 22.06.2023
KW - Semiconductor quantum dot
KW - Upconversation nanocrystal
KW - Luminescence
KW - Quantitative spectroscopy
KW - Photophysics
KW - Quality assurance
KW - Nano
KW - Particle
KW - Quantum yield
KW - Lifetime
KW - Standard
KW - Reference material
KW - Surface analysis
KW - Quantification
PY - 2023
AN - OPUS4-57797
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Functional Luminophores – From Photophysics to Standardized Luminescence Measurements
N2 - Inorganic nanocrystals with linear and nonlinear luminescence in the ultraviolet, visible, near infrared and short-wave infrared like semiconductor quantum dots and spectrally shifting lanthanide-based nanophosphors have meanwhile found applications in the life and material sciences ranging from optical reporters for bioimaging and sensing over security barcodes to solid state lighting and photovoltaics. These nanomaterials commonly have increasingly sophisticated core/shell particle architectures with shells of different chemical composition and thickness to minimize radiationless deactivation at the particle surface that is usually the main energy loss mechanism [1]. For lanthanide-based spectral shifters, particularly for very small nanoparticles, also surface coatings are needed which protect near-surface lanthanide ions from luminescence quenching by high energy vibrators like O-H groups and prevent the disintegration of these nanoparticles under high dilution conditions. [2,3,4]. The identification of optimum particle structures requires quantitative spectroscopic studies focusing on the key performance parameter photoluminescence quantum yield [5,6], ideally flanked by single particle studies to assess spectroscopic inhomogeneities on a particle-to-particle level for typical preparation methods [7,8], Moreover, in the case of upconversion nanoparticles with a multi-photonic and hence, excitation power density (P)-dependent luminescence, quantitative luminescence studies over a broad P range are required to identify particle architectures that are best suited for applications in fluorescence assays up to fluorescence microscopy. Here, we present methods to quantify the photoluminescence of these different types of emitters in the vis/NIR/SWIR and as function of P and demonstrate the importance of such measurements for a profound mechanistic understanding of the nonradiative deactivation pathways in semiconductor and upconversion nanocrystals of different size and particle architecture in different environments.
T2 - Eingeladener Vortrag Uni Erlangen
CY - Erlangen, Germany
DA - 18.01.2023
KW - Semiconductor quantum dot
KW - Upconversion nanocrystal
KW - Luminescence
KW - Quantitative spectroscopy
KW - Photophysics
KW - Quality assurance
KW - Nano
KW - Particle
KW - Quantum yield
KW - Lifetime
KW - Standard
KW - Reference material
KW - Surface analysis
KW - Quantification
PY - 2023
AN - OPUS4-57011
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Matiushkina, Anna
A1 - Abram, Sarah-Luise
A1 - Tavernaro, Isabella
A1 - Richstein, R.
A1 - Reithofer, M. R.
A1 - Andresen, Elina
A1 - Michaelis, Matthias
A1 - Koch, Matthias
A1 - Resch-Genger, Ute
T1 - Quantifying Citrate Surface Ligands on Iron Oxide Nanoparticles with TGA, CHN Analysis, NMR, and RP-HPLC with UV Detection
N2 - Although citrate is frequently used as a surface ligand for nanomaterials (NMs) such as metal, metal oxide, and lanthanide-based NMs in hydrophilic environments due to its biocompatibility and simple replacement by other more strongly binding ligands in postsynthetic surface modification reactions, its quantification on NM surfaces has rarely been addressed. Here, we present a multimethod approach for citrate quantification on iron oxide nanoparticles (IONPs) broadly applied in the life and material sciences. Methods explored include thermogravimetric (TGA) and elemental (CHN) analysis, providing citrate-nonspecific information on the IONP coating, simple photometry, and citrate-selective reversed-phase high-performance liquid chromatography (RP-HPLC) with absorption (UV) detection and quantitative nuclear magnetic resonance spectroscopy (qNMR). Challenges originating from the strongly absorbing magnetic NM and paramagnetic iron species interfering with optical and NMR Methods were overcome by suitable sample preparation workflows. Our multimethod approach to citrate quantification highlights the advantages of combining specific and unspecific methods for characterizing NM Surface chemistry and method cross-validation. It also demonstrates that chemically nonselective measurements can favor an overestimation of the amount of a specific surface ligand by signal contributions from molecules remaining on the NM surface, e.g., from particle synthesis, such as initially employed ligands and/or surfactants. Our results emphasize the potential of underexplored selective RPHPLC for quantifying ligands on NMs, which does not require a multistep sample preparation workflow such as qNMR for many NMs and provides a higher sensitivity. These findings can pave the road to future applications of versatile HPLC methods in NM characterization.
KW - Advanced material
KW - Functional group
KW - Iron oxide
KW - Ligand
KW - Nano
KW - Particle
KW - Quantification
KW - Surface analysis
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648632
DO - https://doi.org/10.1021/acs.analchem.5c03024
SN - 0003-2700
VL - 97
IS - 36
SP - 19627
EP - 19634
PB - American Chemical Society (ACS)
CY - Washington, DC
AN - OPUS4-64863
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Goryacheva, O. A.
A1 - Wegner, Karl David
A1 - Sobolev, A. M.
A1 - Häusler, I.
A1 - Gaponik, N.
A1 - Gorycheva, I. Y.
A1 - Resch-Genger, Ute
T1 - Influence of particle architecture on the photoluminescence properties of silica‑coated CdSe core/shell quantum dots
N2 - Light-emitting nanoparticles like semiconductor nanocrystals (termed quantum dots, QDs) are promising candidates for biosensing and bioimaging applications based on their bright and stable photoluminescent properties. As high-quality QDs are often synthesized in organic solvents, strategies needed to be developed to render them water-dispersible without affecting their optical properties and prevent changes in postmodification steps like the biofunctionalization with antibodies or DNA. Despite a large number of studies on suitable surface modification procedures, the preparation of water-soluble QDs for nanobiotechnology applications still presents a challenge. To highlight the advantages of surface silanization, we systematically explored the influence of the core/multishell architecture of CdSe/CdS/ZnS QDs and the silanization conditions on the optical properties of the resulting silanized QDs. Our results show that the optical properties of silica-coated CdSe/CdS/ZnS QDs are best preserved in the presence of a thick CdS (6 monolayers (ML)) intermediate shell, providing a high photoluminescence quantum yield (PL QY), and a relatively thick ZnS (4.5 ML) external shell, effectively shielding the QDs from the chemical changes during silica coating. In addition to the QD core/shell architecture, other critical parameters of the silica-coating process, that can have an influence on the optical properties of the QD, include the choice of the surfactant and its concentration used for silica coating. The highest PL QY of about 46% was obtained by a microemulsion silica-coating procedure with the surfactant Brij L4, making these water-dispersible QDs to wellsuited optical reporters in future applications like fluorescence immunoassays, biomedicine, and bioimaging.
KW - Nano
KW - Nanomaterial
KW - Particle
KW - Semiconductor
KW - Quantum do
KW - Photoluminescence
KW - Photophysics
KW - Lifetime
KW - Sensor
KW - Mechanism
KW - Surface
KW - Shell
KW - Silica
KW - Silanization
KW - Synthesis
PY - 2022
DO - https://doi.org/10.1007/s00216-022-04005-7
SP - 1
EP - 13
PB - Springer
AN - OPUS4-54546
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Tavernaro, Isabella
T1 - Rational Design of Analyte-responsive Fluorescent Particle Sensors for Life Sciences Applications
N2 - Engineered and tailor-made nanomaterials (NM) are of increasing relevance for current and future developments in the life and material sciences for applications, e.g., as drug carriers, fluorescent sensors, and multimodal labels in bioanalytical assays, and reporters for imaging applications. For instance, NM-based reporters and sensors, that are labelled or stained with a multitude of conventional or sensor dyes, have several advantages as compared to 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. For rational NM design, choosing and tailoring the intrinsic physicochemical properties, such as particle size, size distribution, morphology, and surface chemistry of the NM application-specific considerations like biocompatibility, ease and low cost of preparation, and colloidal stability and performance in the targeted environment must be considered. In this lecture, different design concepts of inorganic, organic, and hybrid NM and microparticles with hydrophilic surface chemistries and different functionalities are presented that can be used for the targeting of lysosomes; and to monitor functional parameters of endo-lysosomal compartments, like pH or enable oxygen sensing.
T2 - Chemical Probes for Lysosomal Biology
CY - York, United Kingdom
DA - 09.09.2024
KW - Luminescence
KW - Quantification
KW - Nano
KW - Particle
KW - Quality assurance
KW - Fluorescence
KW - Method
KW - Uncertainty
KW - Reference material
KW - Sensor
KW - Synthesis
KW - Dye
KW - pH
KW - Silica
KW - Polystyrene
KW - Surface analysis
PY - 2024
AN - OPUS4-62173
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - New project on the quantification of functional groups (FGS) on nanomaterials
N2 - The surface chemistry of nanomaterials controls their interaction with the environment and biological species and their fate and is hence also relevant for their potential toxicity. This has meanwhile led to an increasing interest in validated and preferably standardized methods for the determination and quantification of surface functionalities on nanomaterials and initiated different standardization projects within ISO/TC 229 and IEC/TC 113 as well as interlaboratory comparisons (ILCs) of different analytical methods for the quantification of surface coatings by OECD. Here we present the results of a first ILC on the quantification of the amount of amino functionalities on differently sized inorganic nanoparticles done by division Biophotonics and the National Research Council of Canada (NRC) and the PWI 19257 on the Characterization and Quantification of Surface Functional Groups and Coatings on Nanoobjects approved by ISO/TC 229 (WG2) in fall 2022 that will result in a VAMAS study on this topic organized by division Biophotonics. Key words: nanoparticles, surface analysis, surface functional groups, quantification, optical assay, qNMR, VAMAS, standardization, ICL, quality assurance, reference material.
T2 - Eingeladener Vortrag Universität Erlangen
CY - Erlangen, Germany
DA - 18.01.2023
KW - Quality assurance
KW - Nano
KW - Particle
KW - Standard
KW - Reference material
KW - Surface analysis
KW - Quantification
KW - Interlaboratory comparison
KW - Standardization
KW - VAMAS
PY - 2023
AN - OPUS4-57044
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Matiushkina, Anna
T1 - Quantification of Citrate Ligands on the Surface of Nanoparticles
N2 - In this study, different methods for determining nanoparticle surface ligands including thermogravimetric analysis (TGA) are explored to quantify citrate as one of the most popular hydrophilic ligands on the surface of nanoparticles such as iron oxide nanoparticles (IONPs). The purpose of work is to understand which analytical methods are best suited for surface chemistry analysis of citrate stabilized IONPs and to validate these methods.
T2 - SALSA Make and Measure 2024: Interfaces
CY - Berlin, Germany
DA - 11.09.2024
KW - Nano
KW - Particle
KW - Iron oxide
KW - Ligand
KW - Quantification
KW - Advanced material
KW - Surface analysis
KW - Functional group
PY - 2024
AN - OPUS4-62298
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tan, M.
A1 - Monks, Melissa-Jane
A1 - Huang, D.
A1 - Meng, Y.
A1 - Chen, X.
A1 - Zhou, Y
A1 - Lom, S.-F.
A1 - Würth, Christian
A1 - Resch-Genger, Ute
A1 - Chen, G.
T1 - Efficient sub-15 nm cubic-phase core/Shell upconversion nanoparticles as reporters for ensemble and single particle studies†
N2 - Single particle imaging of upconversion nanoparticles (UCNPs) has typically been realized using hexagonal (β) phase lanthanide-doped sodium yttrium fluoride (NaYF4) materials, the upconversion luminescence (UCL) of which saturates at power densities (P) of several hundred W cm−2 under 980 nm nearinfrared (NIR) excitation. Cubic (α) phase UCNPs have been mostly neglected because of their commonly observed lower UCL efficiency at comparable P in ensemble level studies. Here, we describe a set of sub-15 nm ytterbium-enriched α-NaYbF4:Er3+@CaF2 core/shell UCNPs doped with varying Er3+ concentrations (5–25%), studied over a wide P range of ∼8–105 W cm−2, which emit intense UCL even at a low P of 10 W cm−2 and also saturate at relatively low P. The highest upconversion quantum yield (ΦUC) and the highest particle brightness were obtained for an Er3+ dopant concentration of 12%, reaching the highest ΦUC of 0.77% at a saturation power density (Psat) of 110 W cm−2. These 12%Er3+-doped core/shell UCNPs were also the brightest UCNPs among this series under microscopic conditions at high P of ∼102–105 W cm−2 as demonstrated by imaging studies at the single particle level. Our results underline the potential applicability of the described sub-15 nm cubic-phase core/shell UCNPs for ensemble- and single particle-
level bioimaging.
KW - Nano
KW - Nanomaterial
KW - Upconversion nanoparticle
KW - Lanthanide
KW - Photoluminescence
KW - Quantum yield
KW - Photophysics
KW - Lifetime
KW - Sensor
KW - Surface chemistry
KW - Single particle
KW - Brightness
PY - 2020
DO - https://doi.org/10.1039/d0nr02172e
VL - 12
IS - 19
SP - 10592
EP - 10599
PB - Nanoscale
AN - OPUS4-50908
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kunc, F.
A1 - Nirmalananthan-Budau, Nithiya
A1 - Rühle, Bastian
A1 - Sung, Y.
A1 - Johnston, L.J.
A1 - Resch-Genger, Ute
T1 - Interlaboratory Comparison on the Quantification of Total and Accessible Amine Groups on Silica Nanoparticles with qNMR and Optical Assays
N2 - Risk assessment of nanomaterials requires not only standardized toxicity studies but also validated methods for nanomaterial surface characterization with known uncertainties. In this context, a first bilateral interlaboratory comparison on Surface group quantification of nanomaterials is presented that assesses different reporter-free and labeling methods for the quantification of the total and accessible number of amine functionalities on commercially available silica nanoparticles that are widely used in the life sciences. The overall goal of this comparison is the identification of optimum methods as well as achievable measurement uncertainties and the comparability of the results across laboratories. We also examined the robustness and ease of implementation of the applied analytical methods and discussed method-inherent limitations. In summary, this comparison presents a first step toward the eventually required standardization of methods for surface group quantification.
KW - Nano
KW - Nanomaterial
KW - Surface
KW - Method
KW - QNMR
KW - Quantification
KW - Comparison
KW - Quality assurance
KW - Optical probe
KW - Sensor
KW - Interlabority comparison
KW - Standardization
KW - Optical assay
KW - Functional group analysis
KW - Silica
KW - Particle
KW - Safety
KW - Environment
PY - 2021
DO - https://doi.org/10.1021/acs.analchem.1c02162
SN - 1520-6882
VL - 93
IS - 46
SP - 15271
EP - 15278
PB - ASC Publications
AN - OPUS4-53818
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Billimoria, K.
A1 - Andresen, Elina
A1 - Resch-Genger, Ute
A1 - Goenaga-Infante, H.
T1 - A Strategy for Quantitative Imaging of Lanthanide Tags in A549 Cells Using the Ratio of Internal Standard Elements
N2 - One remaining handicap for spatially resolved elemental quantification in biological samples is the lack of a suitable internal standard (IS) that can be reliably measured across both calibration standards and samples. In this work, multielement quantitative intracellular imaging of cells tagged with lanthanide nanoparticles containing key lanthanides, e.g., Eu and Ho, is described using a novel strategy that uses the ratio of IS elements and LA-ICP-TOFMS analysis. To achieve this, an internal standard layer is deposited onto microscope slides containing either gelatin calibration standards or Euand Ho-tagged cell samples. This IS layer contains both gallium (Ga) and indium (In).
Monitoring either element as an IS individually showed significant variability in intensity signal between sample or standards prepared across multiple microscope slides, which is indicative of the difficulties in producing a homogeneous film at intracellular resolution.
However, normalization of the lanthanide signal to the ratio of the IS elements improved the calibration correlation coefficients from 0.9885 to 0.9971 and 0.9805 to 0.9980 for Eu and Ho, respectively, while providing a consistent signal to monitor the ablation behavior between standards and samples. By analyzing an independent quality control (QC) gelatin sample spiked with Eu and Ho, it was observed that without normalization to the IS ratio the concentrations of Eu and Ho were highly biased by approximately 20% in comparison to the expected values.
Similarly, this overestimation was also observed in the lanthanide concentration distribution of the cell samples in comparison with
the normalized data.
KW - Nanoparticle
KW - Nano
KW - Luminescence
KW - Quality assurance
KW - Synthesis
KW - Standardization
KW - Reference material
KW - ICP-MS
KW - LA-ICP-MS
KW - Quantification
KW - Bioimaging
PY - 2024
DO - https://doi.org/10.1021/acs.analchem.4c02763
SN - 0003-2700
VL - 96
IS - 30
SP - 12570
EP - 12576
AN - OPUS4-60768
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Scholtz, Lena
A1 - Resch-Genger, Ute
T1 - Behind the Paper - Dual color pH probes made from silica and polystyrene nanoparticles and their performance in cell studies
N2 - In this contribution we highlight the importance of comparison for scientific research while developing a new, functional pH sensor system, and the valuable insights this can provide.
KW - Dye
KW - Optical Spectroscopy
KW - pH probe
KW - Silica and Polystyrene Particles
KW - Nano
KW - Surface groups
KW - Safe-by-Design
KW - Cell studies
KW - Sensors
KW - Particle Synthesis
KW - Fluorescence
PY - 2023
UR - https://communities.springernature.com/posts/dual-color-ph-probes-made-from-silica-and-polystyrene-nanoparticles-and-their-performance-in-cell-studies
SP - 1
EP - 2
PB - Springer Nature
CY - London
AN - OPUS4-59150
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
A1 - Pauli, J.
A1 - Güttler, Arne
A1 - Richter, Maria
A1 - Fiedler, Saskia
A1 - Frenzel, Florian
A1 - Wegner, Karl David
A1 - Würth, Christian
T1 - Photoluminescence Quantum Yields of Luminescent Nanocrystals and Particles in the UV/vis/NIR/SWIR
N2 - The rational design of functional luminescent materials such as semiconductor quantum dots and lanthanide-based upconversion nanoparticles, all photophysical and mechanistic studies, and the comparison of different emitters require accurate and quantitative photoluminescence measurements. Particularly the reliable determination of the key performance parameter photoluminescence quantum yield (f), the number of emitted per absorbed photons, and the brightness are of special importance for luminescence applications in the life and material sciences and nano(bio)photonics.[1] In this context, examples for absolute measurements of the photoluminescence quantum yields of UV/vis/NIR/SWIR emissive semiconductor quantum dots and rods, made from different materials, and spectrally shifting lanthanide upconversion nanocrystals with different surface chemistries in transparent matrices are presented including excitation wavelength and power density dependent studies utilizing integration sphere spectroscopy.[2,3] In addition, procedures for the absolute determination of the photoluminescence quantum yields of scattering dispersions of larger size quantum rods and differently sized inorganic particles have been developed as well as procedures for the characterization of solid luminescent nanomaterials such as different perovskites and YAG:Cer converter materials.[4] Thereby, challenges and pitfalls of f measurements in different wavelength regions including the SWIR and material-specific effects related to certain emitter classes are addressed, achievable uncertainties are quantified, and relative and absolute measurements of photoluminescence quantum yield measurements are compared to underline limitations of the former approach. Finally, a set of novel UV/vis/NIR quantum yield standards is presented including their certification with a complete uncertainty budget.[5]
T2 - NANAX 10
CY - Klosterneuburg, Austria
DA - 03.07.2023
KW - Fluorescence
KW - Optical spectroscopy
KW - Reference data
KW - Traceability
KW - NIR
KW - Scattering
KW - Reference material
KW - Certification
KW - Quality assurance
KW - Dye
KW - Reference product
KW - SWIR
KW - Nano
KW - Particle
KW - Perovskite
KW - Integrating sphere spectroscopy
KW - Quantum yield
PY - 2023
AN - OPUS4-58238
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Geißler, Daniel
T1 - NanoGenotox - Automatable Determination of the Genotoxicity of Nanoparticles with DNA-based Optical Assays
N2 - Nanomaterials are used in many different applications in the material and life sciences. Examples are optical reporters, barcodes, and nanosensors, magnetic and optical contrast agents, and catalysts. Due to their small size and large surface area, there are also concerns about their interaction with and uptake by biological systems. This has initiated an ever increasing number of cyctoxicity studies of nanomaterials of different chemical composition and surface chemistry, but until now, the toxicological results presented by different research groups often do not address or differ regarding a potential genotoxicity of these nanomaterials. This underlines the need for a standardized test procedure to detect genotoxicity.1,2
Aiming at the development of fast, easy to use, and automatable microscopic methods for the determination of the genotoxicity of different types of nanoparticles, we assess the potential of the fluorometric γH2AX assay for this purpose. This assay, which can be run on an automated microscopic detection system, relies on the determination of DNA double strand breaks as a sign for genotoxicity.3 Here, we present first results obtained with broadly used nanomaterials like CdSe/CdS and InP/ZnS quantum dots as well as iron oxide, gold, and polymer particles of different surface chemistry with previously tested colloidal stability. These studies will be also used to establish nanomaterials as positive and negative genotoxicity controls or standards for assay performance validation for users of this fluorometric genotoxicity assay. In the future, after proper validation, this microscopic platform technology will be expanded to other typical toxicity assays.
References. (1) Landsiedel, R.; Kapp, M. D.; Schulz, M.; Wiench, K.; Oesch, F., Reviews in Mutation Research 2009, 681, 241-258. (2) Henriksen-Lacey, M.; Carregal-Romero, S.; Liz-Marzán, L. M., Bioconjugate Chem. 2016, 28, 212-221. (3) Willitzki, A.; Lorenz, S.; Hiemann, R.; Guttek, K.; Goihl, A.; Hartig, R.; Conrad, K.; Feist, E.; Sack, U.; Schierack, P., Cytometry Part A 2013, 83, 1017-1026.
T2 - 9th International Conference on Nanotoxicology - New tools in risk assessment of nanomaterials
CY - Dusseldorf/Neuss, Germany
DA - 18.09.2018
KW - Nano
KW - Nanotoxicity
KW - Fluorescence
KW - Quantum dot
KW - Surface
KW - Passivation shell
KW - Automated assay
KW - Nanoparticle
PY - 2018
AN - OPUS4-47540
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Tavernaro, Isabella
T1 - Multivalent presentation of phenylpropenic acid amide inspired ligands by various nanoparticles and their potential use in anti-inflammatory therapy
N2 - Over the years, inflammation has become one of the most rapidly developing areas in medical research, due to new studies indicating its important role in chronical diseases, thrombosis and cancer. A promising target for anti-inflammatory therapy are the multistep adhesion process of leukocytes from the blood vessels into the inflamed tissue. and the numerous involved receptors and ligands. In particular, selectins and their respective carbohydrate ligands can inhibit this key step of the inflammation cascade. In previous work, it was shown that the multivalent presentation of highly negatively charged sulfated and carboxylated ligands on the particle surface can mimic natural selectin binders and increase the inhibition significantly.
Recent studies of the antioxidant and health promoting properties of cocoa, dark chocolate and red clover indicating potential anti-inflammatory properties of their clovamide-type phenylpropenoic acid amides, which are able to inhibit p-selectin expression and platelet-leukocyte interactions. Following the idea of small-molecule targeting drugs, we selected different epitopes and immobilized their sulfated derivatives onto different types nanoparticles, followed by a screening of their performance.
T2 - SALSA Make and Measure 2024: Interfaces
CY - Berlin, Germany
DA - 11.09.2024
KW - Gold colloids
KW - Surface group analysis
KW - Method
KW - Quantification
KW - Screening
KW - Nano
KW - Particle
KW - Synthesis
KW - Quality assurance
KW - Surface ligands
PY - 2024
AN - OPUS4-62159
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fa, X.
A1 - Lin, Sh.
A1 - Yang, J.
A1 - Shen, Ch.
A1 - Liu, Y.
A1 - Gong, Y.
A1 - Qin, A.
A1 - Ou, Jun
A1 - Resch-Genger, Ute
T1 - −808 nm-activated Ca2+ doped up-conversion nanoparticles that release no inducing liver cancer cell (HepG2) apoptosis
N2 - Anear-infrared (NIR) light-triggered release method for nitric oxide (NO) was developed utilizing core/shell NaYF4: Tm/Yb/Ca@NaGdF4:Nd/Yb up-conversion nanoparticles (UCNPs) bearing a mesoporous silica (mSiO2) shell loaded with theNOdonor S-nitroso-N-acetyl-DL-penicillamine (SNAP). To avoid overheating in biological samples, Nd3+ was chosen as a sensitizer, Yb3+ ions as the bridging sensitizer, andTm3+ ions as UV-emissive activator while co-doping with Ca2+ was done to enhance the luminescence of the activatorTm3+.NOrelease from SNAP was triggered by an NIR-UV up-conversion process, initiated by 808nmlight absorbed by the Nd3+ ions.NOrelease was confirmed by the Griess method. Under 808nmirradiation, the viability of the liver cancer cell line HepG2 significantly decreased with increasing UCNPs@mSiO2-SNAP concentration. For a UCNPs@mSiO2-SNAP concentration of 200 μgml−1, the cell survival probability was 47%. These results demonstrate that UCNPs@mSiO2-SNAP can induce the release of apoptosis-inducingNOby NIR irradiation.
KW - Nano
KW - Nanomaterial
KW - Upconversion nanoparticle
KW - Lanthanide
KW - Photoluminescence
KW - Quantum yield
KW - Photophysics
KW - Lifetime
KW - Sensor
KW - Excitation power density
KW - Brightness
KW - NIR
KW - Mechanism
KW - Triggered
KW - Release
KW - Cell
KW - PDT
KW - Dye
KW - Therapy
KW - Surface
KW - Coating
PY - 2022
DO - https://doi.org/10.1088/2050-6120/ac5524
VL - 10
IS - 2
SP - 1
EP - 9
PB - IOP Publishing
AN - OPUS4-54842
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Oskoei, Párástu
A1 - Afonso, Rúben
A1 - Bastos, Verónica
A1 - Nogueira, João
A1 - Keller, Lisa-Marie
A1 - Andresen, Elina
A1 - Saleh, Maysoon I.
A1 - Rühle, Bastian
A1 - Resch-Genger, Ute
A1 - Daniel-da-Silva, Ana L.
A1 - Oliveira, Helena
T1 - Upconversion Nanoparticles with Mesoporous Silica Coatings for Doxorubicin Targeted Delivery to Melanoma Cells
N2 - Melanoma is one of the most aggressive skin cancers and requires innovative therapeutic strategies to overcome the limitations of conventional therapies. In this work, upconversion nanoparticles coated with mesoporous silica and functionalized with folic acid (UCNP@mSiO2-FA) were developed as a targeted nanocarrier system for the delivery of doxorubicin (DOX). The UCNPs were synthesized via thermal decomposition, coated with mesoporous silica shells, and functionalized with folic acid (FA) to enable receptor-mediated targeting. DOX was then loaded into the mesoporous silica coating by adsorption, yielding UCNP@mSiO2-FA-DOX. The different UCNPs were characterized for size, composition, colloidal stability, and loading and release of DOX. This comprehensive physicochemical characterization confirmed a high DOX loading efficiency and a slightly increased drug release under acidic conditions, mimicking the tumour microenvironment. In vitro assays using four melanoma cell lines (A375, B16-F10, MNT-1, and SK-MEL-28) revealed an excellent biocompatibility of UCNP@mSiO2-FA and a significantly higher cytotoxicity of UCNP@mSiO2-FA-DOX compared to unloaded UCNPs, in a dose-dependent manner. Cell cycle analysis demonstrated G2/M phase arrest after treatment with UCNP@mSiO2-FA-DOX, confirming its antiproliferative effect. Overall, UCNP@mSiO2-FA-DOX represents a promising nanoplatform for targeted melanoma therapy, combining active tumour targeting and enhanced anticancer efficacy.
KW - Fluorescence
KW - Synthesis
KW - Nano
KW - Particle
KW - Silica
KW - Cell
KW - Uptake
KW - Drug
KW - Characterization
KW - DOX
KW - Imaging
KW - Toxicity
KW - Release
KW - pH
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653596
DO - https://doi.org/10.3390/molecules31010074
SN - 1420-3049
VL - 31
IS - 1
SP - 1
EP - 18
PB - MDPI AG
AN - OPUS4-65359
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rodriguez, Santiago
A1 - Kumanski, Sylvain
A1 - Ayed, Zeineb
A1 - Fournet, Aurélie
A1 - Bouanchaud, Charlène
A1 - Sagar, Amin
A1 - Allemand, Frédéric
A1 - Baulin, Vladimir A.
A1 - Resch‐Genger, Ute
A1 - Cortés, Juan
A1 - Sibille, Nathalie
A1 - Chirot, Fabien
A1 - Wegner, Karl David
A1 - Antoine, Rodolphe
A1 - Le Guével, Xavier
A1 - Bernadó, Pau
T1 - Programming the Optoelectronic Properties of Atomically Precise Gold Nanoclusters Using the Conformational Landscape of Intrinsically Disordered Proteins
N2 - The rational design of hybrid nanomaterials with precisely controlled properties remains a central challenge in materials science. While atomically precise gold nanoclusters (Au‐NCs) offer molecule‐like control over a metallic core, tuning their optoelectronic behavior via surface engineering is often empirically driven. Here, we establish a design principle by demonstrating that the conformational landscape of intrinsically disordered proteins (IDP) can be used as a programmable scaffold to rationally modulate the photophysical properties of a covalently bound Au‐NC. We synthesized a series of bioconjugates between Au 25 nanoclusters and bioengineered IDPs containing a variable number of cysteine anchoring points. A combination of mass spectrometry, small‐angle X‐ray scattering, and modeling on the conjugates indicates that increasing the number of covalent anchors systematically restricts the conformational ensemble, inducing a progressively more compact protein shell around nanoclusters. This structural rigidification at the interface directly translates into a 15‐fold enhancement of the Au‐NC near‐infrared photoluminescence and a six‐fold increase in its average lifetime. Our findings demonstrate that the conformational plasticity of IDPs and the capacity to engineer them can be harnessed as a molecular tuning knob, moving to a new regime of programmable soft‐matter control over the properties of quantum‐confined nanomaterials for tailored biotechnological applications.
KW - Fluorescence
KW - Custer
KW - Nano
KW - Advanced material
KW - Characterization
KW - Fluorescence quantum yield
KW - Integrating sphere spectroscopy
KW - Thiol ligands
KW - Gold
KW - Surface chemistry
KW - SWIR
KW - Mass spectrometry
KW - Protein
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655086
DO - https://doi.org/10.1002/chem.202502991
SN - 0947-6539
SP - 1
EP - 9
PB - Wiley VHC-Verlag
AN - OPUS4-65508
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Scholtz, Lena
T1 - Luminescent, Semiconductor Nanoparticle-Loadedpolymer Microbeads–Comparingparticlearchitectures
N2 - Luminescent polymer microparticles (PMPs) are applied in various (bio)analytical and diagnostic processes.[1] The staining of these beads is important for the realization of optically distinguishable barcodes that can be read out, e.g., by a flow cytometer or fluorescence microscope. Typically, luminescent semiconductor nanoparticles (NPs) absorb in a broad wavelength range and show narrow emission bands, which enables simultaneous excitation of differently colored luminophores and facilitates a spectral discrimination.[1] This makes them ideal candidates for this purpose and encouraged us to explore and develop a simple, effective approach to luminescent semiconductor NP encoding of polystyrene PMPs and identify suitable synthesis conditions.[2]
Until now, mainly semiconductor quantum dots (QDs) have been used for the synthesis of luminescent PMPs, although NPs with different shapes could introduce beneficial new features. Aiming for the application of our developed procedure to non-spherical NPs, we systematically investigated the luminescence properties of the resulting NP-stained beads using fluorescence and integrating sphere spectroscopy as well as fluorescence and electron microscopy. These studies showed that the suitability of semiconductor NPs for the synthesis of luminescent PMPs depends not only on their shape, but also heavily on their surface chemistry.[3] The successful incorporation of nonspherical NPs opens the path to include even more NPs, and the results can help to deduce future applications for the beads which best suit their specific properties.
T2 - E-MRS Fall Meeting 2025
CY - Warsaw, Poland
DA - 15.09.2025
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Synthesis
KW - Quantum dot
KW - Quantum rod
KW - Platelet
KW - Quantum yield
KW - Polymer particle
KW - Encoding
KW - Surface chemistry
KW - Mechanism
KW - Characterization
KW - Lifetime
KW - Barcode
KW - Polymerization
KW - Method
PY - 2025
AN - OPUS4-64242
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Andresen, Elina
A1 - Resch-Genger, Ute
A1 - Michaelis, Matthias
A1 - Prinz, Carsten
A1 - Würth, Christian
T1 - Time-resolved luminescence spectroscopy for monitoring the stability and dissolution behaviour of upconverting nanocrystals with different surface coatings†
N2 - We demonstrate the potential of time-resolved luminescence spectroscopy for the straightforward assessment and in situ monitoring of the stability of upconversion nanocrystals (UCNPs). Therefore, we prepared hexagonal NaYF4:Yb3+,Er3+ UCNPs with various coatings with a focus on phosphonate ligands of different valency, using different ligand exchange procedures, and studied their dissolution behaviour in phosphate-buffered saline (PBS) dispersions at 20 °C and 37 °C with various analytical methods. The amount of the released UCNPs constituting fluoride ions was quantified by potentiometry using a Fluoride ion-sensitive electrode and particle disintegration was confirmed by transmission electron microscopy studies of the differently aged UCNPs. In parallel, the luminescence features of the UCNPs were measured with special emphasis on the lifetime of the sensitizer emission to demonstrate its suitability as Screening parameter for UCNP stability and changes in particle composition. The excellent correlation between the changes in luminescence lifetime and fluoride concentration highlights the potential of our luminescence lifetime method for UCNP stability screening and thereby indirect monitoring of the release of potentially hazardous fluoride ions during uptake and dissolution in biological systems. Additionally, the developed in situ optical method was used to distinguish the dissolution dynamics of differently sized and differently coated UCNPs.
KW - Fluorescence
KW - Lifetime
KW - Method
KW - Quantification
KW - Stability
KW - Coating
KW - Surface chemistry
KW - Lanthanide
KW - Fluoride
KW - Electrochemistry
KW - ICP-OES
KW - Upconversion
KW - Nano
KW - Particle
KW - Aging
KW - Quality assurance
KW - TEM
PY - 2020
DO - https://doi.org/10.1039/d0nr02931a
VL - 12
IS - 23
SP - 12589
EP - 12601
PB - Royal Society od Chemistry
AN - OPUS4-52088
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Bresch, Harald
A1 - Lexow, Jürgen
A1 - Sturm, Heinz
A1 - Packroff, R.
A1 - Völker, D.
A1 - Mutz, D.
A1 - Bosse, H.
A1 - Gebel, T.
A1 - Pipke, R.
A1 - Marx, R.
A1 - Plitzko, S.
A1 - Niesmann, K.
A1 - Meyer-Plath, A.
A1 - Burgdorf, T.
A1 - Engel, N.
A1 - Epp, A.
A1 - Haase, A.
A1 - Herzberg, F.
A1 - Laux, P.
A1 - Oberemm, A.
A1 - Sommer, Y.
A1 - Tentschert, J.
A1 - Ulm, G.
A1 - Schwirn, K.
A1 - Liesegang, C.
T1 - Nanomaterialien und andere innovative Werkstoffe: anwendungssicher und umweltverträglich
T1 - Nanomaterials and other advanced materials: application safety and environmental compatibility
N2 - Mit einer langfristigen Forschungsstrategie begleiten die für die Sicherheit von Mensch und Umwelt zuständigen Bundesoberbehörden (Umweltbundesamt, Bundesinstitut für Risikobe-wertung, Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, Bundesanstalt für Materialfor-schung und -prüfung und Physikalisch-Technische Bundesanstalt) die rasch voranschreiten-de Entwicklung neuer Materialien unter den Gesichtspunkten des Arbeits-, Verbraucher- und Umweltschutzes. Die Strategie steht daher in enger Verbindung zu den öffentlichen Förder-programmen für Nanomaterialien und andere innovative Werkstoffe, z. B. des BMBF („Vom Material zur Innovation“) und der EU („Horizon 2020“).
Die Forschungsstrategie baut auf den bisherigen Ergebnissen der 2008 begonnenen und 2013 erstmals bilanzierten gemeinsamen Forschungsstrategie der Bundesoberbehörden „Nanotechnologie - Gesundheits- und Umweltrisiken von Nanomaterialien"1 auf und erweitert den Blickwinkel auch auf andere Materialinnovationen, bei denen vergleichbare Risiken für Mensch und Umwelt bestehen oder abgeklärt werden müssen. Darüber hinaus greift sie die Idee „anwendungssichere chemische Produkte“2 aus der Initiative „Neue Qualität der Arbeit“ (INQA) des Bundesministeriums für Arbeit und Soziales (BMAS) und das Konzept der nach-haltigen Chemie3 auf, das vom Bundesministerium für Umwelt, Naturschutz, Bau und Reak-torsicherheit (BMUB) unterstützt wird. Durch eine anwendungssichere und umweltverträgli-che Gestaltung innovativer Materialien und ihrer Folgeprodukte sollen nicht akzeptable Risi-ken für Mensch und Umwelt von Anfang an weitgehend ausgeschlossen werden. Dies kann erreicht werden durch
1.
die Verwendung sicherer Materialien ohne Gefahreneigenschaften für Mensch und Umwelt (direkte Anwendungssicherheit) oder
2.
eine Produktgestaltung, die über den gesamten Lebenszyklus emissionsarm und umweltverträglich ist (integrierte Anwendungssicherheit) oder
3.
eine Unterstützung des Anwenders (product stewardship) durch den Hersteller bei technischen, organisatorischen und persönlichen Schutzmaßnahmen zur sicheren Verwendung und Entsorgung des Produktes (unterstützte Anwendungssicherheit).
Die Fortschreibung der Forschungsstrategie soll als Bestandteil des Nanoaktionsplans 2020 der Bundesregierung Beiträge der Ressortforschung zu folgenden Schwerpunkten leisten:
•
Charakterisierung und Bewertung der Risiken von Materialinnovationen
•
Unterstützung von Forschungseinrichtungen und Unternehmen
•
Fortschreiben von Rechtsvorschriften und Praxisempfehlungen
1
http://www.baua.de/nn_47716/de/Themen-von-A-Z/Gefahrstoffe/Nanotechnologie/pdf/Forschungsstrategie.pdf
2 http://www.baua.de/de/Themen-von-A-Z/Gefahrstoffe/Nachhaltige-Chemie/Nachhaltige-Chemie.html
3
http://www.umweltbundesamt.de/themen/chemikalien/chemikalien-management/nachhaltige-chemie
2
•
Gesellschaftliche Akzeptanz
Die Forschungsstrategie soll mit Projekten und anderen forschungsnahen Aktivitäten umge-setzt werden. Dies umfasst die eigene Forschung der Häuser, die extramurale Ausschrei-bung und Vergabe von Forschungsdienstleistungen sowie die Beteiligung an vorwiegend öffentlich geförderten Drittmittelprojekten. Hinzu kommen Aktivitäten im Rahmen der Politik-beratung und der hoheitlichen Aufgaben. Mit inter- und transdisziplinären Ansätzen soll die Risiko- und Sicherheitsforschung enger mit der Innovationsforschung und Materialentwick-lung verknüpft werden. Die Forschungsstrategie ist aufgrund der raschen Entwicklungen auf diesem Gebiet für den Zeitraum bis 2020 angelegt. Die Forschungsziele adressieren die in diesem Zeitraum voraussichtlich umsetzbaren Forschungsansätze. Die Forschungsstrategie wird durch einen Arbeitskreis begleitet und spätestens mit Ablauf des Nanoaktionsplans 2020 evaluiert und angepasst.
KW - Forschungsstrategie
KW - Bundesoberbehörden
KW - Nanomaterialien
KW - Innovative Werkstoffe
KW - Nano
PY - 2016
UR - https://www.bam.de/_SharedDocs/DE/Downloads/nano-forschungsstrategie-2016.pdf?__blob=publicationFile&v=3
UR - http://www.baua.de/de/Themen-von-A-Z/Gefahrstoffe/Nanotechnologie/pdf/Fortschreibung-Forschungsstrategie.pdf?__blob=publicationFile&v=3
UR - http://www.bmub.bund.de/fileadmin/Daten_BMU/Download_PDF/Nanotechnologie/forschungsstrategie_bundesoberbehoerden_de_bf.pdf
SP - 1
EP - 28
PB - UBA/BfR/BAuA/BAM/PTB
CY - Berlin
AN - OPUS4-37526
LA - mul
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -