TY  - THES
U1  - Dissertation / Habilitation
A1  - Lange, Julia
T1  - Spezifisch bindende magnetische Nanopartikel in magnetischen Relaxationsmessungen
N2  - keine Angaben
N2  - The aim of this study was to show the suitability of a new SQUID-based technique, called magnetorelaxometry, for the specific detection of binding reactions in vitro and its potential in vivo. Magnetic nanoparticles (MNPs) modified with biologically active molecules are utilised as probes. The method is based on the magnetisation of MNPs in a magnetic field and the following detection of their relaxing magnetisation. The specificity of the method depends on the difference of the magnetic relaxation mechanism of MNPs in a liquid phase and immobilised particles. In a liquid phase the particles relax as whole in the surrounding fluid (brownian relaxation). Is the mobility of the magnetic nanoparticles reduced, the magnetisation of the sample decays via the Néel relaxation mechanism. A preparation method for streptavidin- and antibody-conjugated MNPs was developed. Binding reactions in homogeneous and heterogeneous phases were studied. Therefore solid-and liquid-phase immunoassays, magnetic relaxation immunoassays (MARIAs), were established and compared to well-established ELISAs and particles size measurements. Magnetic nanoparticle relaxation measurements provided an increased detection limit compared to particle size measurements and a slightly reduced detection limit compared to ELISA. The in vivo applicability of the method was proven. Furthermore a new magneto-optical in vitro method was developed, that is based on the measurement of the relaxation of the birefringence of magnetised MNPs.
KW  - Technologie
KW  - Magnet
KW  - Nanopartikel
KW  - Signalgeber
KW  - Relaxationsmessung
KW  - Magnetic nanoparticles
KW  - Photon Correlation Spetroscopy
KW  - Magnetic Relaxation Immnoassay
KW  - Magnetorelaxometry
KW  - Brown-Relaxation
Y2  - 2001
U6  - https://nbn-resolving.org/urn:nbn:de:gbv:9-200106-3
UN  - https://nbn-resolving.org/urn:nbn:de:gbv:9-200106-3
ER  -