TY - CONF A1 - Carl, Peter T1 - Progressing Towards Rapid Multiplex Detection: A Fluorescence Immunoassay for Ergot Alkaloids, Trichothecenes, and Fusarium Toxins N2 - Ergot alkaloids, potent mycotoxins produced by Claviceps spp., particularly Claviceps purpurea, pose significant health risks when they contaminate rye and related cereals, leading to ergotism in humans and mammals [1]. In response, the European Union has established Regulation 2023/915, setting maximum residue levels for the sum of 12 principal ergot alkaloids and other mycotoxins including fumonisins (FUM), deoxynivalenol (DON), zearalenone (ZEN), and T2/HT2 toxins in food products. Given the prevalent co-occurrence of mycotoxins, their simultaneous detection is crucial for ensuring the safety of food and feed [2, 3]. Traditionally, chromatographic techniques such as liquid chromatography coupled with (tandem) mass spectrometry (LC-MS/MS) have been employed for multiplex detection of mycotoxins [4, 5]. While effective, these methods require specialized facilities, expensive equipment, and skilled personnel. Immunoassays like ELISA and lateral flow assays offer a more accessible alternative for rapid mycotoxin detection, yet they generally lack the capability for concurrent multi-toxin screening. This study introduces the SAFIA (Suspension Array Fluorescence Immunoassay), a particle-based immunoassay utilizing fluorescence-encoded microparticles for the simultaneous detection of multiple analytes [6, 7]. The assay's innovative advancement comes with the inclusion of ergot alkaloids, a novel addition to its existing detection capabilities for fusarium toxins and trichothecenes, thereby expanding its scope to a broader range of mycotoxins. The assay employs antibodies targeting the ergoline moiety common to all major ergot alkaloids, facilitated by a synthesized hapten mimicking the ergoline structure. This hapten was conjugated to amino-functionalized beads, and a panel of five monoclonal antibodies was evaluated for hapten recognition, binding specificity, and competitive binding efficiency. Our findings demonstrate that all antibodies displayed similar affinities towards the hapten and lysergol (a stable and less hazardous analogue of lysergic acid used for calibration), achieving detection limits as low as 2 ppb. Cross-reactivity studies and analysis of round-robin test material indicated a significant underestimation of ergot alkaloid levels in samples. However, accurate detection of ergot alkaloids remains feasible through the application of a correction factor to the results, which compensates for this underestimation and ensures the assay's effectiveness. Despite this adjustment, the necessity for enhancements in antibody specificity to improve assay accuracy is evident. Furthermore, the inclusion of the ergot assay in a multiplexed setup for detecting FUM, DON, ZEN, and T-2 toxins showed no interference, although an unexpected inhibition among four out of five ergot antibodies was observed. This underscores the need for an improved immunogen structure to achieve optimal detection of ergot alkaloids. In conclusion, our study presents a promising approach for the multiplexed detection of ergot alkaloids alongside other mycotoxins, highlighting the potential of SAFIA in enhancing food and feed safety through improved mycotoxin screening. Future work will focus on refining antibody specificity and assay configurations to overcome current limitations and ensure accurate, comprehensive mycotoxin detection. T2 - Mycotoxin-Workshop CY - Vienna, Austria DA - 02.06.2024 KW - Mycotoxins KW - LC-MS/MS KW - Quality assurance KW - Food safety PY - 2024 AN - OPUS4-61065 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Russo, Francesco Friedrich T1 - Gas chromatography low energy-electron ionisation mass spectrometry (GC LE EI MS) as a softer ionisation method for non-targeted analysis N2 - Mass spectrometry (MS)-based non-targeted screening (NTS) methods are important tools due to their high throughput and sensitivity. The high throughput and sensitivity have contributed to the method’s increased adoption in forensic, health, and environmental sciences. Gas chromatography electron ionisation mass spectrometry (GC-EI-MS) methods in particular show high reproducibility of fragmentation patterns and have the advantage of vast spectral libraries. Nevertheless, the high energy imparted to molecules by standard 70 eV EI sources frequently results in a loss of the molecular ion signal. The depleted molecular ion signal renders the identification of compounds not included in spectral libraries more difficult, as straightforward molecular formula assignment is not achieved. Furthermore, the high degree of fragmentation and the resulting depletion of signals with high m/z, leads to reduced discriminatory power. Soft ionisation techniques alleviate the inherent disadvantages of EI-MS in molecular formula determination but do not harness the knowledge stored in EI spectral libraries. Low energy (LE)-EI-MS, being a softer version of EI, has recently seen increased interest. LE-EI-MS keeps high spectral similarity with the standard 70 eV EI while reducing the depletion of signals of molecular ions and of higher m/z ions. The hyphenation of LE-EI-MS to GC is straightforward, keeping the high chromatographic resolution. LE-EI-MS has shown promise in fluxomics [1], doping analytics [2, 3], metabolomics [4], fingerprinting of foods [5, 6], and the identification of isomers in motor oil mixtures [7]. Our objective is the comparison of LE-EI-MS to alternative soft ionisation methods, e.g. APCI-MS, and the development of a non-targeted LE-EI-MS workflow, including highly automated data processing and annotation pipeline. In a first phase 13 compound libraries are measured at 14, 18, and 70 eV. Molecular ion abundance and similarity to standard 70 eV spectra are evaluated. Furthermore, common neutral losses and fragments are identified and included as an extension of a previously published annotation tool (R package InterpretMSSpectrum [8, 9]). T2 - Adlershofer Forschungforum CY - Berlin, Germany DA - 11.11.2024 KW - Mass Spectrometry (MS) KW - Non-targeted screenings (NTS) KW - Gas Chromatography (GC) KW - Low Energy Electron Ionisation Mass Spectrometry (LE-EI-MS) PY - 2024 AN - OPUS4-61666 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Russo, Francesco F. T1 - Gas chromatograph low energy-electron ionisation mass spectrometry (GC-LE-EI-MS) in non targeted analysis N2 - Non targeted screenings (NTS) are an important tool for forensic, health, and environmental sciences. Mass spectrometry (MS) based NTS methods are characterised by high throughput and high sensitivity. Gas chromatography electron ionisation mass spectrometry (GC EI-MS) methods show high reproducibility of fragmentation patterns, good separation, and vast spectral libraries. Nevertheless, the high energy imparted to molecules by standard 70eV EI sources results in a high degree of fragmentation with a possible loss of the molecular ion signal. The loss of molecular ion signal makes the identification of compounds absent from spectral libraries more difficult by precluding a straightforward molecular formula assignment. Furthermore, the high degree of fragmentation, and the resulting depletion of high m/z signals, results in a reduced discriminatory power. The disadvantages of EI MS are approached by soft ionisation techniques, e.g. electrospray ionisation (ESI). More recently, low energy (LE) EI-MS has awakened interest as a softer version of EI, which still keeps high similarity with the standard 70 eV EI and the good chromatographic properties of GC, while reducing the depletion of higher m/z ion signals and of molecular ions. LE-EI-MS has shown promise in fluxomics[1], doping analytics[2, 3], metabolomics[4], fingerprinting of foods[5, 6], and the identification of isomers in motor oil mixtures[7]. Our objective is the comparison of LE-EI-MS to alternative soft ionisation methods, e.g. APCI-MS, and the development of a non-targeted LE-EI-MS workflow, including a highly automated data processing and annotation pipeline. In a first phase 13 compound libraries (705 compounds) will be measured at 14, 18, and 70 eV. Molecular ion abundance and similarity to standard 70 eV spectra are going to be evaluated. Furthermore, common neutral losses and fragments will be identified and included into an annotation tool. If the tool shows satisfying performance, it will be published (either as a standalone package or as an expansion to the InterpretMSSpectrum[8, 9] R package). T2 - International Symposium on Chromatography (ISC) 2024 CY - Liverpool, UK DA - 06.10.2024 KW - MS KW - Low Energy Electron Ionisation Mass Spectrometry (LE-EI-MS) KW - Mass Spectrometry (MS) KW - Gas Chromatography Mass Spectrometry (GC-MS) KW - Gas Chromatography (GC) PY - 2024 AN - OPUS4-61349 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaeger, Carsten A1 - Lintelmann, Jutta A1 - Franke, Raimo A1 - Artati, Anna A1 - Cecil, Alexander A1 - Broda, Frank A1 - Klawonn, Frank A1 - Erban, Alexander A1 - Kopka, Joachim A1 - Fuchs, Beate A1 - Sommer, Ulf A1 - Neumann-Schaal, Meina A1 - O'Connor, Gavin T1 - Analytical practices, use and needs of standard and reference materials in the German-speaking metabolomics community: results of an online survey N2 - Introduction Since the early 2000s, metabolomics has grown rapidly, becoming integral to fields like life sciences, health, and environmental research. This expansion has led to the formation of national and international societies, such as Germany’s DGMet, to tackle emerging challenges. One of DGMet’s goals is to improve measurement quality by assessing community needs for harmonization and standardization. A recent survey within the German-speaking community aimed to identify current practices and gaps in the use of chemical standards and reference materials, to guide future standardization efforts and collaborative initiatives. Methods An online survey was conducted between June 2023 and April 2024. The survey consisted of 38 key questions and was open to research institutions from Germany, Austria, and Switzerland. Results The survey was accessed by 68 laboratories, with 23 institutes providing complete or partial responses (34% response rate), which is comparable to rates reported in similar surveys within the metabolomics and lipidomics communities. Respondents were mainly experienced researchers from Germany, focusing mainly on health-related (“red”) metabolomics, as indicated by 78% of the respondents, followed by microbial (“grey”, 48%) and plant (“green”, 39%) metabolomics (multiple answers possible). The use of targeted methods was reported more frequently (91%) than that of non-targeted methods (78%), whereas metabolite fractions studied were equally split between polar, midpolar and lipid fractions (83% each). Human (74%), mouse (61%) and Arabidopsis (30%) were the most frequently studied organisms. Most participants used synthetic chemical standards for instrument qualification (83%), calibration (78%), and metabolite identification (74%), while matrix reference materials were mainly applied for quality control (52%) and method validation (44%). There was a strong demand for more standards, especially for metabolite identification and quantification, with cost being a major barrier, particularly for isotopically labelled standards and certified reference materials. Conclusions Valuable insights into the use of standards and reference materials within the German-speaking metabolomics community were obtained. Moving forward, the community should address critical gaps in metabolomics standardization. To achieve this, it must share its knowledge, articulate its needs clearly, and actively engage in joint efforts with national metrology institutes and international standardization initiatives. KW - Reference material KW - Chemical standard KW - Metabolomics KW - Mass spectrometry PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647303 DO - https://doi.org/10.1007/s11306-025-02360-x VL - 21 IS - 6 SP - 1 EP - 11 PB - Springer-Nature CY - Heidelberg AN - OPUS4-64730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Rudolf T1 - Immunochemical sensing of key pollution indicators in the water cycle N2 - Organic micropollutants - often termed emerging contaminants - are increasingly detected throughout the water cycle, from drinking water to wastewater. Monitoring their distribution requires trace analytical methods that are fast, cost-effective, matrix-tolerant, and ideally portable. Immunoanalytical techniques, using antibodies, nanobodies, or fragments, offer high selectivity and sensitivity, though typically in single-analyte or oligoplexing formats. To maximize their utility, environmentally relevant indicator compounds should be selected to reflect pollutant input, partial removal during treatment, and persistence in wastewater and surface water. ELISA remains a robust method for high-throughput analysis. We have assays available for the com-pounds carbamazepine, diclofenac, cetirizine, estrone, sulfamethoxazole, caffeine, cocaine, bisphenol A, and isolithocholic acid. Simpler formats like fluorescence polarization immunoassays (FPIA) and lateral flow immunoassays (LFIA)—familiar from COVID-19 rapid tests — enable on-site screening. Multiplexing is feasible with bead-based microarrays and electrochemical sensors on microfluidic platforms, which additionally offer portability and the latter even independence from optical systems. Despite these advances, the development of highly selective, high-affinity binders remains a critical bottleneck. Promising strategies to overcome this include computational hapten design, nanobody engineering, and in silico optimization of binder sequences—enhanced by artificial intelligence for targeted database mining. These approaches, coupled with scalable recombinant expression, are poised to expand the binder repertoire essential for any immunoanalytical platform. This growing repository will be key to advancing immunochemical diagnostics across the water cycle. T2 - 5th International Symposium on Nanobody for Immunological Analysis and Application CY - Guangzhou, China DA - 15.11.2025 KW - Antibodies KW - Immunoassay KW - Microfluidics KW - Biosensor KW - Trace substances KW - Electrochemical detection PY - 2025 AN - OPUS4-64923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Rudolf T1 - How can antibodies help us in the risk assessment of pharmaceuticals in the environment? N2 - The widespread use of pharmaceuticals has led to their persistent presence in various environmental compartments, raising concerns about ecological and human health risks since they pose a significant threat to non-target organisms and human health, necessitating robust methods for environmental risk assessment.   Traditional analytical methods, such as liquid chromatography-mass spectrometry (LC-MS), offer high sensitivity and specificity but are often resource-intensive, require complex sample preparation, limiting their applicability for large-scale or real-time monitoring. In this context, antibody-based analytical techniques present a promising complementary approach for the detection and quantification of pharmaceutical residues in environmental matrices.   Antibodies, due to their high specificity and affinity, enable the development of immunoassays such as ELISA, lateral flow assays, fluorescence-based formats, and electrochemical sensors that are rapid, cost-effective, and adaptable to field conditions. These methods can be tailored to target a wide range of pharmaceutical compounds, including antibiotics and endocrine disruptors. Moreover, antibody-based assays facilitate high-throughput screening and can be integrated into portable platforms for on-site analysis, thereby enhancing temporal and spatial resolution in environmental monitoring.   This presentation explores the potential of antibodies in environmental risk assessment, focusing on their application in detecting trace levels of pharmaceuticals in water, soil, and biota. They are presented as a complementary and powerful tool for rapid, cost-effective screening in the lab and that also can be deployed for on-site analysis in the field.   The talk also discusses recent advances in antibody engineering, multiplexing capabilities [1], and the integration of immunoassays with sensor technologies [2].   Case studies illustrate how immunoanalytical data can help in finding potential contamination hotspots [3], hazard identification, pollution source tracking, and the generation of crucial data for predictive models on environmental fate and effects. Antibody-based methods can also help in early warning systems and the evaluation of mitigation strategies, contributing to a more comprehensive and proactive risk assessment framework, eventually to regulatory decision-making, ultimately aiding in the protection of ecosystems and public health. T2 - ICRAPHE - 6th International Conference on Risk Assessment of Pharmaceuticals in the Environment CY - Aveiro, Portugal DA - 20.10.2025 KW - Antibodies KW - Immunoassay KW - Microfluidics KW - Electrochemical detection KW - Biosensor PY - 2025 AN - OPUS4-64922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kleinbub, Sherin A1 - Braymer, Joseph J A1 - Pfeiffer, Friedhelm A1 - Dyall-Smith, Mike A1 - Spirgath, Kristin A1 - Alfaro-Espinoza, Gabriela A1 - Koerdt, Andrea T1 - From Genes to Black Rust: Genomic insights into corrosive methanogens N2 - Within the past ten years, genetic evidence has been increasing for the direct role that microbes play in microbiologically influenced corrosion (MIC), also known as biocorrosion or biodeterioration. One prominent example is the correlation between the corrosion of metal and the presence of genes encoding an extracellular [NiFe]-hydrogenase (MIC hydrogenase) in the methanogenic archaeon, Methanococcus maripaludis. In this study, DNA sequencing and bioinformatic analysis were used to classify the MIC hydrogenase as belonging to a core set of genes, the MIC core, found so far in Methanococci and Methanobacteria classes of methanogens. Genetic evidence is provided for the mobilization of the MIC core via multiple mechanisms, including a horizontal gene transfer event from Methanobacteria to Methanococci and a newly described MIC-transposon. A detailed comparison of M. maripaludis genomes further pointed to the relevance that cell wall modifications involving N-glycosylation of S-layer proteins and the MIC hydrogenase likely play in methanogen-induced MIC (Mi-MIC). Microscopic analysis of corrosive methanogens encoding the MIC core indicated that Methanobacterium-affiliated strain IM1 can form extensive biofilms on the surface of corrosion products whereas individual cells of M. maripaludis Mic1c10 were only found localized to crevices in the corrosion layer. An updated model of Mi-MIC involving two modes of action is presented, which predicts that the propensity of cells to adhere to iron surfaces directly influences the rate of corrosion due to the localization of the MIC hydrogenase at the metal-microbe interface. KW - Biocorrosion KW - Hydrogenases KW - Metalloprotein KW - Microbes PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649425 DO - https://doi.org/10.1093/femsmc/xtaf018 SN - 2633-6685 VL - 6 SP - 1 EP - 19 PB - Oxford University Press (OUP) AN - OPUS4-64942 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hantschke, Luisa Lamberta T1 - Determination of background values of PFAS in representative soil samples in Germany N2 - Per- and polyfluoroalkyl substances (PFAS) are a large and ever-growing class of chemicals that are widely used. Due to the strength of the C-F bond, they do not decompose but accumulate in the environment posing a risk for nature and humans alike. While the use of some PFAS, like perfluorooctanoic acid (PFOA) and perfluorooctanoic sulfonic acid (PFOS) is already regulated in the EU, new ‘precursor’ substances are used to replace them. However, these precursors may be equally harmful to the environment. In recent years, many ‘hot spot’ sites with high PFAS contaminations in the soils have been distinguished,but no German-wide background values have been determined yet. Knowing these background values is crucial to understand the degree of PFAS contamination, underpinning future regulatory decisions. 600 soil samples are freshly taken at different sites all over Germany. PFAS are extracted from all samples. The extracts are analysed using LC-MS/MS with 30 PFAS as target compounds. Eluates are produced and analysed using targeted LC-MS/MS. To determine the amount of precursor substances not included in the targeted list, total oxidisable precursor (TOP) assays are performed with different approaches. Additionally, 50 samples taken at the same locations in 2012 are analysed to determine temporal trends of PFAS contamination. The determination of total extractable organically bound fluorine (EOF) is planned for comparison. The aim of the project is to obtain a broad overview of the status and development of the PFAS contamination in soil in Germany. By the preparation and analysis of eluates, the leaching behaviour of the analytes and thereby their mobility in the environment is investigated, helping to understand the transport of PFAS from contaminated soil to water. The use of different TOP assay methods allows to compare their results and usability in routine analysis, thereby giving insights into the amount of PFAS contamination hidden to targeted analysis and helping inspire future analysis strategies. The future comparison of these results to EOF analysis may further underline this point. The large number of samples and the geographic distribution of the sampling is unprecedented in Germany and allows to determine high-risk sites and ‘hot spots’. In the future, the insights from the project may be used as a guide for the political regulation of uses of PFAS. T2 - ANAKON23 CY - Vienna, Austria DA - 11.04.2023 KW - PFAS KW - Soil contamination KW - Background values KW - BBodSChV PY - 2023 AN - OPUS4-57755 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Devi, Sarita T1 - Metal-Organic Magnetic Framework-Based Immunosensor for Label-free Electrochemical sensing of NeuroToxin N2 - A metal-organic framework (MOF)-integrated microfluidic flow-cell (MFC) based electrochemical immunodetection of the tetanus toxoid (TT) is presented. The magnetic property of Fe-MOF helped to hold them on the working electrode (WE) at detection zone of MFC, surpassing the requirement of additional conjugation chemistry, and the conductive property was utilized to observe the change in signal efficiency in the presence of TT. The one-pot hydrothermal synthesis of iron-based MOF (Fe-MOF) was performed using the Fe3+/Fe2+ precursors as 1.2/1 mmol and dual ligands, tetrahydroxy-1,4-benzoquinone and 2 aminobenzene-1,4-dicarboxylic acid. The human anti-TT mAb SA13 was purified in-house from the cell culture supernatant of SA13 hybridoma cells by Protein-A affinity. SDS-PAGE showed the high purity as of a band just above the 140kDa mark in the eluate lane. The hydrodynamic radius of 5.35 nm and thermal unfolding temperature of 73°C were typical for antibodies. Indirect ELISA confirmed the high binding affinity. The mAb was conjugated on the Fe-MOF/Phe surface with the help of ethylenediamine (Fe MOF/Phe/EDA/anti-TTmAb). A specifically tailored MFC, made of Poly(methyl methacrylate) substrate was crafted at the BAM workshop. The limit of detection (LOD) and analytical sensitivity of the TT biosensor was 9.4 ng/ml [y=1.93E-5 + (-1.86E-6)x] and 11.6 μA/ng ml-1cm-2, respectively. The good reproducibility, selectivity, and stability show the applicability of these Fe-MOFs for detecting various other toxins. T2 - European Materials Research Society (E-MRS) Spring Meeting CY - Strasbourg, France DA - 26.05.2025 KW - Magnetic Metal-Organic Framework KW - Tetanus toxoid KW - Antibody KW - Electrochemistry KW - Biosensor PY - 2025 AN - OPUS4-63492 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Riedel, Soraya T1 - Application of 3,3’,5,5’-Tetramethylbenzidine (TMB) in Amperometric Immunoassays for Mycotoxin Detection N2 - Electrochemical methods make great promise to meet the demand for user-friendly on-site devices for monitoring important parameters. Food industry often runs own lab procedures, e.g., for mycotoxin analysis, but it is a major goal to simplify analysis, linking analytical methods with miniaturized technologies. Enzyme-linked immunosorbent assays, with photometric detection of the horseradish peroxidase (HRP) substrate 3,3’,5,5’-tetramethylbenzidine (TMB), form a good basis for sensitive detection. To provide a straight-forward approach for the miniaturization of the detection step, we have studied the pitfalls of the electrochemical TMB detection. By cyclic voltammetry, it could be shown that TMB electrochemistry is strongly dependent on the pH and the electrode material. It was found that screen-printed gold electrodes and a very low pH value (pH 1) are well-suited to perform the electrochemical detection of TMB, due to the reversible character of the redox reaction under these conditions. Under these conditions, a good signal stability over several measuring cycles is achieved, providing the basis for analyzing multiple samples. In contrast to this, for carbon screen-printed electrodes, it was found that the signal response has changed after the electrochemical reaction with TMB at pH 1. At moderately acidic conditions (pH 4), neither with carbon nor with gold electrodes a reproducible electrochemical detection of TMB could be achieved. Based on these findings, we created a smartphone-based, electrochemical, immunomagnetic assay for the detection of ochratoxin A (OTA) and ergometrine in food samples. A competitive assay is performed on magnetic beads using HRP and TMB/H2O2 to generate the signal. Enzymatically oxidized TMB is quantified after addition of H2SO4 by amperometry with screen-printed gold electrodes in a custom-made wall-jet flow cell. The results are in good correlation with the established photometric detection method, providing a solid basis for sensing of further analytes in HRP-based assays using the newly developed miniaturized smartphone-based, electrochemical, immunomagnetic assay. T2 - 73rd Annual Meeting of the ISE CY - Online meeting DA - 12.09.2022 KW - Cylic Voltammetry KW - Immunoassay KW - Mycotoxins KW - Amperometry KW - Electrochemistry PY - 2022 N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S. AN - OPUS4-55793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Riedel, Soraya A1 - Hülagü, Deniz A1 - Bennet, Francesca A1 - Carl, Peter A1 - Flemig, Sabine A1 - Schmid, Thomas A1 - Schenk, J. A. A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf T1 - Electrochemical Immunomagnetic Ochratoxin A Sensing: Steps Forward in the Application of 3,3’,5,5’- Tetramethylbenzidine in Amperometric Assays N2 - Electrochemical methods offer great promise in meeting the demand for user-friendly on-site devices for Monitoring important parameters. The food industry often runs own lab procedures, for example, for mycotoxin analysis, but it is a major goal to simplify analysis, linking analytical methods with smart technologies. Enzyme-linked immunosorbent assays, with photometric detection of 3,3’,5,5’-tetramethylbenzidine (TMB),form a good basis for sensitive detection. To provide a straightforward approach for the miniaturization of the detectionstep, we have studied the pitfalls of the electrochemical TMB detection. By cyclic voltammetry it was found that the TMB electrochemistry is strongly dependent on the pH and the electrode material. A stable electrode response to TMB could be achieved at pH 1 on gold electrodes. We created a smartphonebased, electrochemical, immunomagnetic assay for the detection of ochratoxin A in real samples, providing a solid basis forsensing of further analytes. KW - Ochratoxin A KW - Amperometry KW - Cyclic voltammetry KW - Electrochemistry KW - Immunoassay PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530421 DO - https://doi.org/10.1002/celc.202100446 N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S. VL - 8 IS - 13 SP - 2597 EP - 2606 AN - OPUS4-53042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Devi, Sarita A1 - Riedel, Soraya A1 - Döring, Sarah A1 - Hiller, Lukas A1 - Kaliyaraj Selva Kumar, Archana A1 - Flemig, Sabine A1 - Singh, Chandan A1 - Konthur, Zoltán A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf T1 - Antibodies Functionalized Magnetic Fe-Metal-Organic Framework Based Biosensor for Electrochemical Detection of Tetanus Neurotoxin N2 - This work presents a metal-organic framework (MOF)-integrated microfluidic flow-cell (MFC) based immunodetection of the tetanus toxoid (TT) using electrochemical technique for the first time. The magnetic property of Fe-MOF helped to hold them on the working electrode at detection zone of MFC surpassing the requirement of additional conjugation chemistry, whereas the conductive property was utilized to observe the change in signal efficiency in the presence of TT. The one-pot hydrothermal synthesis of a magnetic and conductive iron-based MOF (Fe-MOF) was performed using the Fe3 +/Fe2+ precursors as 1.2/1 mmol and dual ligands, i.e., tetrahydroxy-1,4-benzoquinone and 2-aminobenzene-1,4-dicarboxylic acid. The Fe-MOF was conjugated with L-phenylalanine (Fe-MOF/Phe) to increase its electric conductivity owing to the enhanced electron flow rate. The human monoclonal antibody SA13 against TT (anti-TT mAb) was conjugated on the Fe-MOF/Phe surface with the help of ethylenediamine (Fe-MOF/Phe/EDA/anti-TT mAb). The binding affinity of Fe-MOF/Phe/EDA/anti-TT mAb for the TT antigen was evaluated using cyclic voltammetry technique. The limit of detection of the Fe-MOF/Phe/EDA/anti-TT mAb-based biosensor for TT was 9.4 ng/ml in spiked buffer. This study shows the applicability of these Fe-MOFs in the detection of various other microbial toxins or other biomolecules. KW - Antikörper KW - Elektrochemischer Immunoassay KW - Molecular Organic Framework (MOF) KW - Microfluidics KW - Rekombinant PY - 2025 DO - https://doi.org/10.1016/j.snb.2025.137381 SN - 0925-4005 VL - 431 SP - 1 EP - 12 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-62673 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -