A biosensor is described. The biosensor includes a fixed multilayer stack
providing a magnetization oscillation, a voltage source electrically
coupled to the fixed multilayer stack, and a binding molecule covalently
bonded to the biosensor. The voltage source provides a direct current
through the fixed multilayer stack to generate the magnetization
oscillation and a target molecule including a magnetic nanoparticle forms
a complex with the binding molecule and alters the magnetization
oscillation.