Described are embodiments of an invention for a sample assembly with an electrical conductor for generating an electromagnetic field to speed up the tagging of target antigens with antiparticles for detection of the antigens by electromagnetic read heads. A sample assembly includes a surface with a first set of antibodies bonded thereon. Target antigens are bonded with the first set of antibodies. A second set of antibodies bonded to nanoparticles are exposed to the sample surface to bond with the target antigens. The electrical conductor generates an electromagnetic field that moves the nanoparticle-labeled antibodies toward the antigens to shorten the time to complete their bonding process.