A rapid magnetic bead-based immunoassay for sensitive determination of diclofenac

Increasing contamination of environmental waters with pharmaceuticals represents an emerging threat for the drinking water quality and safety. In this regard, fast and reliable analytical methods are required to allow quick countermeasures in case of contamination. Here, we report the development of a magnetic bead-based immunoassay (MBBA) for the fast and cost-effective determination of the analgesic diclofenac (DCF) in water samples, based on diclofenac-coupled magnetic beads and a robust monoclonal anti-DCF antibody. A novel synthetic strategy for preparation of the beads resulted in an assay that enabled for the determination of diclofenac with a significantly lower limit of detection (400 ng/L) than the respective enzyme-linked immunosorbent assay (ELISA). With shorter incubation times and only one manual washing step required, the assay demands for remarkably shorter time to result (< 45 min) and less equipment than ELISA. Evaluation of assay precision and accuracy with a series of spiked water samples yielded results with low to moderate intra- and inter-assay variations and in good agreement with LC–MS/MS reference analysis. The assay principle can be transferred to other, e.g., microfluidic, formats, as well as applied to other analytes and may replace ELISA as the standard immunochemical method. Graphical abstractBundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347Indo-German Science and Technology Centre http://dx.doi.org/10.13039/501100018761Bundesanstalt für Materialforschung und -prüfung (BAM) (4232)Peer Reviewe

Exchange-bias instability in a bilayer with an ion-beam imprinted stripe pattern of ferromagnetic/antiferromagnetic interfaces

Theis-Broehl K, Wolff M, Westphalen A, et al. Exchange-bias instability in a bilayer with an ion-beam imprinted stripe pattern of ferromagnetic/antiferromagnetic interfaces. PHYSICAL REVIEW B. 2006;73(17): 174408.We have investigated the magnetization arrangement in an in-plane stripe pattern with alternating exchange-bias domains. The stripe pattern was produced by ion bombardment induced magnetic patterning, which changed locally the exchange-bias direction at the ferromagnet/antiferromagnet interface, but not the magnetic or antiferromagnetic properties of the Co70Fe30 and Mn83Ir17 layers, respectively. For the analysis of the magnetic domain structure evolution along the hysteresis loop we used a combination of experimental techniques: magneto-optical Kerr effect, Kerr microscopy, polarized neutron reflectometry, and off-specular scattering of polarized neutrons with polarization analysis. Instead of a perfect antiparallel alignment we found that the magnetization in neighboring stripes is periodically canted with respect to the stripe axis so that the net magnetization of the ferromagnetic film turns almost perpendicular to the stripes. At the same time the projection of the magnetization vector onto the stripe axis has a periodically alternating sign. The experimental observations are explained and quantitatively described within the frame of a phenomenological model, taking into account interfacial exchange bias, intralayer exchange energy, and uniaxial anisotropy. The model defines conditions which can be used for tailoring nano- and micro-patterned exchange-bias systems with different types of magnetic order

PLA-Abfälle im Abfallstrom

Biobased plastics are now being used more and more frequently, especially in packaging. Waste disposal providers and their established recycling systems face new challenges. Many of them fear that bio-based plastics disrupt the traditional waste and disposal pathways. In order to investigate to what extent bio-plastics can be recycled in the established plastic recycling system, the Federal Ministry of Food and Agriculture (BMEL) funded, through its project executing agency, agency of renewable resources e. V. (FNR), a collaborative project. The project partners have dealt with the mechanical (mechanical, physical) and feedstock (chemical) recycling of packaging from the biobased plastic polylactic acid (PLA). The focus was on both industrial and post-consumer waste. PLA is one of the most chemically novel bioplastics and is often used in the packaging sector. In terms of recycling, however, there are still great precautions that it could disrupt conventional disposal flows. Following the completion of the research project, the project partners have presented recommendations for the waste management of bio-based plastics in the form of a result paper, which is printed below. The detailed study entitled „Sustainable recycling strategies for products and waste from bio-based plastics“ will be published in the form of a final report. Further information on the project can also be found at: www.fnr.de/projektfoerderung/projekte-und-ergebnisse/projektverzeichnis under the project numbers: 22010814, 22031812, 22019212, 22031312, 22012414