Magnetic Nanoparticle Sensors

Abstract

Many types of biosensors employ magnetic nanoparticles (diameter = 5–300 nm) or magnetic particles (diameter = 300–5,000 nm) which have been surface functionalized to recognize specific molecular targets. Here we cover three types of biosensors that employ different biosensing principles, magnetic materials, and instrumentation. The first type consists of magnetic relaxation switch assay-sensors, which are based on the effects magnetic particles exert on water proton relaxation rates. The second type consists of magnetic particle relaxation sensors, which determine the relaxation of the magnetic moment within the magnetic particle. The third type is magnetoresistive sensors, which detect the presence of magnetic particles on the surface of electronic devices that are sensitive to changes in magnetic fields on their surface. Recent improvements in the design of magnetic nanoparticles (and magnetic particles), together with improvements in instrumentation, suggest that magnetic material-based biosensors may become widely used in the future.

Tailored and Functionalized Magnetite Particles for Biomedical and Industrial Applications

“…Three types of biosensors, (i) magnetic relaxation witches, (ii) magnetic particle relaxation sensors, and (iii) magnetoresistive sensors, were coated with different biosensing principles and magnetic materials for instrumentation (Josephson, 2009). Magnetic relaxation switch assay-sensors are based on the effects of the magnetic particles exert on water proton relaxation rates.…”

Detection of Cancer Biomarkers With Nanotechnology

“…Many types of cancer biomarker detection systems employ surface-functionalized magnetic nanomaterials to recognize specific molecular targets (Koh and Josephson, 2009). Due to their biocompatibility, superior magnetic properties and stability, Iron Oxide Nanoparticles (IONPs), have been applied in a wide range of areas, such as MRI, cell labeling and biosensing.…”

Magnetic Detection Structure for LOC Immunoassays, Multiphysics Simulations and Experimental Results

“…The other approaches use mechanical and magnetic based methods. The systems based on magnetic approaches hold promising perspectives due to their miniaturization possibility [4,5]. Some attempts have been made in order to embed magnetic sensors such as GMR, TMR, and planar Hall Effect sensors [6].…”