A biosensor utilizing bio-functionalized magnetic nanoparticles is provided. An external magnetic field is applied to a suspension of magnetic nanoparticles. A linearly polarized incident light is applied to the suspension of magnetic nanoparticles. A photocurrent from polarized light scattering by bio-functionalized magnetic nanoparticles in liquid is detected. The magneto-optic sensing technique is applied to a micro-fluidic channel for rapid and sensitive detection with a small sample amount, and subsequent magnetic separation for detoxification. This technique is used for the detection of Brownian relaxation with time sweep as well as frequency sweep. The magneto-optical sensor enables rapidly detecting changes in local dynamic properties of the magnetic nanoparticles in liquids and magnetic modulation of ferromagnetic particles in liquid provides increased signal sensitivity.
CONTRACTUAL ORIGIN OF THE INVENTION
The United States Government has rights in this invention pursuant to Contract No. W-31-109-ENG-38 between the United States Government and The University of Chicago and/or pursuant to Contract No. DE-AC02-06CH11357 between the United States Government and UChicago Argonne, LLC representing Argonne National Laboratory.