TY - JOUR A1 - Beyer, Sebastian A1 - Prinz, Carsten A1 - Schürmann, Robin A1 - Feldmann, Ines A1 - Zimathies, Annett A1 - Blocki, Anna A1 - Bald, Ilko A1 - Schneider, Rudolf A1 - Emmerling, Franziska T1 - Ultra-sonication of ZIF-67 crystals results in ZIF-67 nano-flakes N2 - Zeolitic Imidazolate Frameworks (ZIFs) are crystalline materials that comprise of metal nodes and Imidazole derivatives as linkers. ZIF-67 is often used in polymer composite materials e. g. for gas separation membranes. Post-synthesis treatment of ZIF-67 crystals with ultrasound leads to unforeseen plasticity that resulted in sintered ZIF-67 and ZIF-67 nano-flakes. Consequently, ultrasound increases the external surface area of ZIF-67 which might improve e.g. blending with polymers in composite materials. These new morphologies of ZIF-67 were characterized by transmission electron, scanning electron, and atomic force microscopy. The ultrasound treatment of ZIF-67 did not result in the formation of an amorphous framework or a meta-stable crystal structure as indicated by powder x-ray diffraction. In addition, ultra-sonicated ZIF-67 retained the high gas adsorption capacity and pore size compared to synthesized ZIF-67. The morphological changes are hard to detect with standard analytical methods that are usually utilized for MOF characterization. These findings also suggest that sonochemical treatment of ZIFs leads to structural effects beyond increasing the amount of nucleation clusters during sono-chemical synthesis, which is currently not addressed in the field. KW - ZIF PY - 2016 DO - https://doi.org/10.1002/slct.201601513 SN - 2365-6549 VL - 1 IS - 18 SP - 5905 EP - 5908 AN - OPUS4-38496 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fernandez, L. A1 - Esteves, V. I. A1 - Cunha, A. A1 - Schneider, Rudolf A1 - Tome, J. P. C. T1 - Photodegradation of organic pollutants in water by immobilized porphyrins and phthalocyanines N2 - New methods for water treatment are required as a result from an increasing awareness in the reduction of the pollution impact in the environment. In the perspective of the photo-oxidation of organic pollutants present in water, the principal incentive for the preparation of heterogeneous photocatalysts is their easy recovery from the reaction mixture, which allows their reuse in successive runs, minimizing the loss of their original photocatalytic properties. Different types of supports can be used in the immobilization of photoactive species, such as porphyrins (Pors) and phthalocyanines (Pcs). This mini-review will consider the different methodologies for the immobilization of Pors and Pcs and their photocatalytic performance in the photodegradation of organic pollutants in water, addressing also their recycling ability in successive water treatments. KW - Porphyrins KW - Phthalocyanines KW - Water treatment KW - Organic pollutants KW - Advanced oxidation processes KW - Heterogeneous photocatalysis KW - TiO2 KW - Microporous KW - Nanoparticles PY - 2016 DO - https://doi.org/10.1142/S108842461630007X VL - 2016 IS - 20 SP - 150 EP - 166 PB - World Scientific Publishing AN - OPUS4-38503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scala-Benuzzi, M. L. A1 - Takara, E. A. A1 - Alderete, M. A1 - Soler-Illia, G. J. A. A. A1 - Schneider, Rudolf A1 - Raba, J. A1 - Messina, G. A. T1 - Ethinylestradiol quantification in drinking water sources using a fluorescent paper based immunosensor N2 - In this work we report a novel paper-based analytical device read-out via LED-induced fluorescence detection (FPAD) for the quantification of the emerging pollutant ethinylestradiol (EE2) in river water samples. The PAD was used as a reaction platform for a competitive enzyme immunoassay. For the PAD development, microzones of filter paper, printed by a wax printing method, were modified with amino-functionalized SBA-15 and subsequently, anti-EE2 specific antibodies were covalently immobilized. The determination of EE2 in water was carried out by adding a fixed concentration of EE2 conjugated with the enzyme horseradish peroxidase (HRP) to samples and standards. Then, the FPAD were added and incubated for 10 min. Finally, the detection was performed by the reaction of 10-acetyl-3,7-dihydroxyphenoxazine (ADHP) whose oxidation is catalyzed by HRP in the presence of H2O2, obtaining the highly fluorescent resorufin (R). Resorufin was detected by LED excitation at 550 nm, observing emission at 585 nm. The EE2 concentration in the samples was inversely proportional to the relative fluorescence obtained from the enzymatic reaction products. The FPAD assay showed a detection Limit (LOD) of 0.05 ng L−1 and coefficients of variation (CV) below 4.5% within-assay and below 6.5% between-assay, respectively. The results obtained show the potential suitability of our FPAD for the selective and sensitive quantification of EE2 in river water samples. In addition, it has the PADs advantages of being disposable, easy to apply and inexpensive. KW - Immunoassay KW - Arzneimittel KW - Antikörper KW - LED-induzierte Fluoreszenz KW - Paper based devices KW - Mesoporöses Silica KW - Partikel PY - 2018 DO - https://doi.org/10.1016/j.microc.2018.05.038 SN - 0026-265X VL - 141 SP - 287 EP - 293 PB - Elsevier B.V. CY - Amsterdam, NL AN - OPUS4-45269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abdelshafi, Nahla A. A1 - Bell, Jérémy A1 - Rurack, Knut A1 - Schneider, Rudolf T1 - Microfluidic electrochemical immunosensor for the trace analysis of cocaine in water and body fluids N2 - Quick but accurate testing and on‐the‐spot monitoring of cocaine in oral fluids and urine continues to be an important toxicological issue. In terms of drug testing, a number of devices have been introduced into the market in recent decades, notably for workplace inspection or roadside testing. However, these systems do not always fulfill the requirements in terms of reliability, especially when low cut‐off levels are required. With respect to surface water, the presence of anthropogenic small organic molecules such as prescription and over‐the‐counter pharmaceuticals as well as illicit drugs like cannabinoids, heroin, or cocaine, has become a challenge for scientists to develop new analytical tools for screening and on‐site analysis because many of them serve as markers for anthropogenic input and consumer behavior. Here, a modular approach for the detection of cocaine is presented, integrating an electrochemical enzyme‐linked immunosorbent assay (ELISA) performed on antibody‐grafted magnetic beads in a hybrid microfluidic sensor utilizing flexible tubing, static chip and screen‐printed electrode (SPE) elements for incubation, recognition, and cyclic voltammetry measurements. A linear response of the sensor vs. the logarithm of cocaine concentration was obtained with a limit of detection of 0.15 ng/L. Within an overall assay time of 25 minutes, concentrations down to 1 ng/L could be reliably determined in water, oral fluids, and urine, the system possessing a dynamic working range up to 1 mg/L. KW - ELISA KW - Kokain KW - Lab-on-chip KW - Speichel KW - Urin KW - Drogenanalytik KW - Schnelltest KW - Biosensor PY - 2018 DO - https://doi.org/10.1002/dta.2515 SN - 1942-7611 VL - 11 IS - 3 SP - 492 EP - 500 PB - Wiley-VCH CY - Hoboken, New Jersey, USA AN - OPUS4-46888 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scala-Benuzzi, M. L. A1 - Raba, J. A1 - Soler-Illia, G. J. A. A. A1 - Schneider, Rudolf A1 - Messina, G. A. T1 - Novel electrochemical paper-based immunocapture assay for the quantitative determination of ethinylestradiol in water samples N2 - We report a novel and innovative electrochemical paper-based immunocapture assay (EPIA) to address the need for ultrasensitive detection of emerging pollutants without regulatory status and whose effects on environment and human health are not completely yet understood. In particular, we present the application of this system toward highly sensitive detection of the emerging pollutant ethinyl estradiol (EE2). The EPIA approach is based on the use of paper microzones modified with silica nanoparticles (SNs) and anti-EE2 specific antibodies for capture and preconcentration of EE2 from river water samples. After the preconcentration procedure, the paper microzones are placed onto a screen-printed carbon electrode modified with electrochemically reduced graphene (RG). The bound EE2 is subsequently desorbed adding a diluted solution of sulfuric acid on the paper microzones. Finally, recovered EE2 is electrochemically detected by OSWV. The proposed novel methodology showed an appropriate LOD and linear range for the quantification of EE2 for water samples with different origins. The nonsophisticated equipment required, the adequate recovery values obtained (from 97% to 104%, with a RSD less than 4.9%), and the appropriate LOD and linear range value (0.1 ng L−1 and 0.5−120 ng L−1, respectively) achieved by our immunocapture sensor present significant analytical figures of merit, particularly when the routine quantification of EE2 is considered. In addition, our System was based on electrochemical paper-based technology, which allows obtainment of portable, easy-to-use, inexpensive, and disposable devices. The EPIA can also serve as a general-purpose immunoassay platform applicable to quantitation of other drugs and emerging pollutants in environmental samples. KW - Immunoassay KW - EE2 KW - Estrogens KW - Screen-printed electrode KW - Square-wave voltammetry PY - 2018 DO - https://doi.org/10.1021/acs.analchem.8b00028 SN - 0003-2700 SN - 1520-6882 VL - 90 IS - 6 SP - 4104 EP - 4111 PB - American Chemical Society CY - Washington, D.C., USA AN - OPUS4-44690 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Almeida, Ângela A1 - Calisto, Vânia A1 - Domingues, M. Rosário M. A1 - Esteves, Valdemar I. A1 - Schneider, Rudolf A1 - Soares, Amadeu M.V.M. A1 - Figueira, Etelvina A1 - Freitas, Rosa T1 - Comparison of the toxicological impacts of carbamazepine and a mixture of its photodegradation products in Scrobicularia plana N2 - In the aquatic environment, pharmaceutical drugs are submitted to degradation processes, where pho-todegradation is one of the most important mechanisms affecting the fate, persistence and toxicity of thecompounds. Carbamazepine, a widely used antiepileptic, is known to suffer photodegradation in waterbodies and generate photoproducts, some of them with higher potential toxicity than the parent com-pound. Therefore, to evaluate the toxic effects of CBZ when combined with its photoproducts, an acuteexposure (96 h) with the edible clam Scrobicularia plana was performed using environmental concentra-tions of CBZ (0.00–9.00 µg/L) irradiated (and non-irradiated) with simulated solar radiation. The analysisof the irradiated CBZ solutions by mass spectrometry revealed the formation of 5 photoproducts, includ-ing acridine (a compound known to be carcinogenic). Oxidative stress results showed that the exposureto CBZ photoproducts did not increase the toxicity to clams, by comparison with the parent compound. KW - Pharmaceutical drugs KW - Photodegradation KW - Biomarkers KW - Oxidative stress KW - Bivalves PY - 2017 DO - https://doi.org/10.1016/j.jhazmat.2016.05.009 VL - 323 SP - 220 EP - 232 PB - Elsevier B.V. AN - OPUS4-39151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scala-Benuzzi, M. L. A1 - Soler-Illia, G. J. A. A. A1 - Rabia, J. A1 - Battaglini, F. A1 - Schneider, Rudolf A1 - Pereira, S. V. A1 - Messina, G. A. T1 - Immunosensor based on porous gold and reduced graphene platform for the determination of EE2 by electrochemical impedance spectroscopy N2 - In this work, we report an electrochemical immunosensor to detect ethinylestradiol in water samples, using electrochemical impedance spectroscopy (EIS) as a detection technique. For the development of this immunosensor, the direct modification of the working electrode of a screen-printed carbon electrode was carried out. First, to reduce the resistance of the electrode, electroreduced graphene was incorporated on the surface. Second, a porous gold structure was electrodeposited on reduced graphene by electrodeposition and the dynamic hydrogen bubble template assisted method. Thus, a marked increase in surface area was obtained for anti-EE2 antibodies immobilization. Subsequently, the specific anti-EE2 antibodies were covalently immobilized using α-lipoic acid for attaching them to the gold surface. The electrode modified with the antibodies was incubated for 30 min in the samples containing EE2, producing the specific Antigen antibody binding. As the charge transfer resistance of a redox probe in the electrode surface is governed by the surface blocking effects, the charge transfer resistance was related to the amount of EE2 captured to realize a quantitative determination. For this, the EIS measurements were performed in a 4 mM [Fe(CN)6]4−/3− solution in 0.1 M KCl. The obtained Nyquist diagrams were adjusted using the Randles circuit as an equivalent circuit to obtain the corresponding resistances. The developed methodology showed good selectivity, precision, and sensitivity; although the LOD obtained was higher than those presented in other published articles, it turned out to be an alternative that allows the determination of ethinylestradiol using a simple disposable electrode. KW - Ethinylestradiol KW - Biosensor KW - Elektrochemisch KW - Impedanz PY - 2021 DO - https://doi.org/10.1016/j.jelechem.2021.115604 SN - 1572-6657 VL - 897 SP - 115604 EP - 115611 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-54048 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oberleitner, Lidia A1 - Garbe, L.-A. A1 - Dahmen-Levison, Ursula A1 - Schneider, Rudolf T1 - Improved strategies for selection and characterization of new monoclonal anticarbamazepine antibodies during the screening process using feces and fluorescence polarization immunoassay N2 - Immunoassays are suitable tools for high-throughput screenings. The prerequisite for accurate determinations by these methods is the selection of an excellent antibody. The production and selection of monoclonal antibodies is usually a tedious process. In this study, new strategies for improving antibody production and characterization were applied. This includes the monitoring of the immunization progress in mice through antibodies extracted from feces, which allows a time-resolved and animal-friendly monitoring of the immune response. Additionally, fluorescence polarization immunoassay (FPIA) could be successfully applied for fast and easy examination of cell culture supernatants and the investigation of antibody/antigen interactions including kinetics and fluorescence properties. These methods simplify the selection of the optimal antibody. As a target analyte, carbamazepine was chosen. This is a widely used antiepileptic drug which also frequently occurs in the environment. The new antibody enables CBZ determination in the concentration range 0.66–110 µg L-1 within 10 min using a high-throughput microtiter plate-based FPIA, and between 1.4 and 79 µg L-1 within 5 min applying an automated cuvette-based FPIA instrument, and from 0.05–36 µg L-1 using ELISA. The measurements were performed at a non-equilibrium state which improved the sensitivity and selectivity of the assays. Due to low cross-reactivity especially towards the main CBZ metabolite and other pharmaceuticals (<1%), this antibody gives the opportunity for application in medical and environmental analyses. KW - Antikörper KW - Emerging Pollutants KW - Schadstoffe KW - Monoklonal KW - Pharmazeutika KW - Arzneistoffe KW - Assay KW - Pesticide parathion-methyl KW - Waste-water KW - Samples KW - Pharmaceuticals KW - Quantification PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-392473 DO - https://doi.org/10.1039/c6ay01968d SN - 1759-9660 VL - 8 SP - 6883 EP - 6894 PB - Royal Society of Chemistry CY - London AN - OPUS4-39247 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Raysyan, Anna A1 - Moerer, R. A1 - Coesfeld, Bianca A1 - Eremin, S. A1 - Schneider, Rudolf T1 - Fluorescence polarization immunoassay for the determination of diclofenac in wastewater N2 - Pharmacologically active compounds are often detected in wastewater and surface waters. The nonsteroidal anti-inflammatory drug diclofenac (DCF) was included in the European watch list of substances that requires its environmental monitoring in the member states. DCF may harmfully influence the ecosystem already at concentrations ≤ 1 μg L−1. The fast and easy quantification of DCF is becoming a subject of global importance. Fluorescence polarization immunoassay (FPIA) is a homogeneous mix-and-read method which does not require the immobilization of reagents. FPIA can be performed in one phase within 20–30 min, making it possible to analyse wastewater without any complicated pre-treatment. In this study, new tracermolecules with different structures, linking fluorophores to derivatives of the analyte, were synthesized, three homologous tracers based on DCF, two including a C6 spacer, and one heterologous tracer derived from 5-hydroxy-DCF. The tracer molecules were thoroughly assessed for performance. Regarding sensitivity of the FPIA, the lowest limit of detection reached was 2.0 μg L−1 with a working range up to 870 μg L−1. The method was validated for real wastewater samples against LC-MS/MS as reference method with good agreement of both methods. KW - Abwasser KW - Umweltschadstoffe KW - Antikörper KW - Antibody PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518398 DO - https://doi.org/10.1007/s00216-020-03058-w SN - 1618-2642 VL - 413 IS - 4 SP - 999 EP - 107 PB - Springer CY - Heidelberg AN - OPUS4-51839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ecke, Alexander A1 - Bell, Jérémy A1 - Schneider, Rudolf T1 - A three-dimensional microfluidic flow cell and system integration for improved electrochemical substrate detection in HRP/TMB-based immunoassays N2 - Immunoassays, based on the recognition and capture of analytes by highly selective antibodies, are now used extensively in all areas of diagnostics, but the challenge is to further integrate them into online sensors. To improve the transition from laboratory immunoassays to immunosensors, we have developed a complete flow system, based on a microfluidic core flow cell to enable automated detection of one of the most commonly used immunoassay substrates, TMB, by chronoamperometry. The architecture and fluidic optimisation of the system showed that a specially designed 3D flow cell allows higher flow rates (500 μL min−1) than a standard enlarged microfluidic channel (50 μL min−1) resulting in a significantly shorter detection time of 30 seconds per sample and making the system more robust against interferences due to bubble formation in the chip. The electrochemical measurements showed an improved signal-to-noise ratio (SNR) and thus higher sensitivity for a model immunoassay for diclofenac (SNR = 59), compared to the analytical performance of a conventional laboratory microplate-based assay with optical detection (SNR = 19). In general, this system facilitates the conversion of any conventional immunoassay into an immunosensor with automatic and continuous detection. KW - Microfluidic KW - Immunoassay KW - Electrochemical KW - Mikrofluidik KW - Immunassay KW - Elektrochemie PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580159 DO - https://doi.org/10.1039/d3sd00095h VL - 2 SP - 887 EP - 892 PB - Royal Society of Chemistry CY - London, United Kingdom AN - OPUS4-58015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -