Magneto-Optic Biosensor Using Bio-Functionalized Magnetic Nanoparticles

摘要

Magnetic nanoparticles are leading to the development of more sensitive, rapid, and cost-effective biological sensors. These sensors can be used for a variety of applications including the detection of medical conditions and bio-terrorist threats. Recently, there has been an increased interest in magnetic nanoparticles with biologically relevant ligand coatings. These nanoparticles can have many biological and medical uses including targeted drug delivery, magnetic separation, hyperthermal treatment, and biosensors. Researchers have developed a magnetic-optic biosensor that uses biofunction-alized magnetic nanoparticles. The long-range interaction between magnetic nanoparticles and an external magnetic field enables manipulation and sensitive detection of those particles for improved biosensors. The process involves applying a time-varying external magnetic field and a linearly polarized incident laser light to a suspension of magnetic nanoparticles. The resulting transmitted or reflected light and its polarization are recorded with a photodetector. This allows for the determination of the Brownian relaxation time, which may indicate hydro-dynamic radius changes upon chemical binding of the target to the magnetic nanoparticles.