Progress in Using Magnetic Nanoobjects for Biomedical Diagnostics

A magnetic biochip using the combination of both magnetic nanoobjects as markers and magnetoresistive sensors has proven to be competitive to standard fluorescent DNA‐detection at low concentrations. Magnetic nanoobjects additionally provide the unique possibility to actively manipulate biomolecules, on‐chip, which paves the way to an integrated ‘magnetic lab‐on‐a‐chip’ containing detection and manipulation. It is shown that the hybridization process can be accelerated on a biochip. Looking forward, a paradigm change from the ‘magnetic lab‐on‐a‐chip’ to a ‘magnetic lab‐on‐a‐bead’ is discussed as a future device solution. The ferromagnetic nanoobjects themselves are thereby directly used both as molecular recognition site and as detection unit.