TY  - JOUR
A1  - Vogel, Patrick
A1  - Rückert, Martin Andreas
A1  - Friedrich, Bernhard
A1  - Tietze, Rainer
A1  - Lyer, Stefan
A1  - Kampf, Thomas
A1  - Hennig, Thomas
A1  - Dölken, Lars
A1  - Alexiou, Christoph
A1  - Behr, Volker Christian
T1  - Critical Offset Magnetic PArticle SpectroScopy for rapid and highly sensitive medical point-of-care diagnostics
JF  - Nature Communications
N2  - Magnetic nanoparticles (MNPs) have been adapted for many applications, e.g., bioassays for the detection of biomarkers such as antibodies, by controlled engineering of specific surface properties. Specific measurement of such binding states is of high interest but currently limited to highly sensitive techniques such as ELISA or flow cytometry, which are relatively inflexible, difficult to handle, expensive and time-consuming. Here we report a method named COMPASS (Critical-Offset-Magnetic-Particle-SpectroScopy), which is based on a critical offset magnetic field, enabling sensitive detection to minimal changes in mobility of MNP ensembles, e.g., resulting from SARS-CoV-2 antibodies binding to the S antigen on the surface of functionalized MNPs. With a sensitivity of 0.33 fmole/50 µl (≙7 pM) for SARS-CoV-2-S1 antibodies, measured with a low-cost portable COMPASS device, the proposed technique is competitive with respect to sensitivity while providing flexibility, robustness, and a measurement time of seconds per sample. In addition, initial results with blood serum demonstrate high specificity.
KW  - biochemical assays
KW  - characterization and analytical techniques
KW  - magnetic properties and materials
KW  - nanoparticles
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300893
VL  - 13
ER  - 
TY  - JOUR
A1  - Karak, Suvendu
A1  - Stepanenko, Vladimir
A1  - Addicoat, Matthew A.
A1  - Keßler, Philipp
A1  - Moser, Simon
A1  - Beuerle, Florian
A1  - Würthner, Frank
T1  - A Covalent Organic Framework for Cooperative Water Oxidation
JF  - Journal of the American Chemical Society
N2  - The future of water-derived hydrogen as the “sustainable energy source” straightaway bets on the success of the sluggish oxygen-generating half-reaction. The endeavor to emulate the natural photosystem II for efficient water oxidation has been extended across the spectrum of organic and inorganic combinations. However, the achievement has so far been restricted to homogeneous catalysts rather than their pristine heterogeneous forms. The poor structural understanding and control over the mechanistic pathway often impede the overall development. Herein, we have synthesized a highly crystalline covalent organic framework (COF) for chemical and photochemical water oxidation. The interpenetrated structure assures the catalyst stability, as the catalyst’s performance remains unaltered after several cycles. This COF exhibits the highest ever accomplished catalytic activity for such an organometallic crystalline solid-state material where the rate of oxygen evolution is as high as ∼26,000 μmol L\(^{–1}\) s\(^{–1}\) (second-order rate constant k ≈ 1650 μmol L s\(^{–1}\) g\(^{–2}\)). The catalyst also proves its exceptional activity (k ≈ 1600 μmol L s\(^{–1}\) g\(^{–2}\)) during light-driven water oxidation under very dilute conditions. The cooperative interaction between metal centers in the crystalline network offers 20–30-fold superior activity during chemical as well as photocatalytic water oxidation as compared to its amorphous polymeric counterpart.
KW  - water oxidation
KW  - sustainable energy source
KW  - covalent organic framework
KW  - catalyst
KW  - crystalline
KW  - catalysis
KW  - nanoparticles
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-287591
UR  - https://pubs.acs.org/doi/10.1021/jacs.2c07282
SN  - 0002-7863
VL  - 144
IS  - 38
ER  -