Suitability of magnetic single- and multi-core nanoparticles to detect protein binding with dynamic magnetic measurement techniques

摘要: We investigated the binding of biotinylated proteins to various streptavidin functionalized magnetic nanoparticles with different dynamic measurement techniques examine their potential for homogeneous bioassays. As particle systems, single-core a nominal core diameter 30 nm as well multi-core hydrodynamic sizes varying between nominally 60 and 100 were chosen. experimental techniques, fluxgate magnetorelaxometry (MRX), complex ac susceptibility (ACS) measurements phase lag rotating field sample magnetization are applied. MRX only suited detection small analytes if multivalency causes cross-linking, thus forming larger aggregates. ACS showed all nanoparticle systems shift imaginary part's maximum towards frequencies. In dominating Brownian mechanism exhibit an increase upon in frequency range. The coexistence Neel relaxation processes can cause more change behavior, demonstrated systems.