Magneto-Optic Biosensor Uses Bio-Functionalized Magnetic Nanoparticles (ANL-IN-05-122)
This schematic of the magneto-optic detection system illustrates a magnetic nanoparticle stimulated by external time-varying magnetic fields. The dynamic magnetic response is detected by either the transmission (Faraday or Cotton-Mouton Effect) or reflection (Kerr Effect) of polarized light. The time-dependence of either transmission or reflection can help determine the local viscosity or changes to the hydrodynamic radius.
Magnetic nanoparticles and their broad array of properties are enabling scientists to develop increasingly sensitive, rapid, and cost-effective biological sensors. The sensors promise an array of applications as wide-ranging as the discovery of a new drug or remote detection of toxins or contaminants in air or water.Description
Researchers at Argonne National Laboratory have developed a unique magneto-optic biosensor that uses magnetic nanoparticles with biological function capability. The biosensor works when an external magnetic field and laser are applied to magnetic nanoparticles held in suspension, enabling scientists to manipulate the particles. A photodetector records the resulting light and its polarization, measuring Brownian relaxation time, which may indicate hydrodynamic radius changes upon chemical binding of the target to the magnetic nanoparticles.
Argonne’s magneto-optic biosensor can be used to measure either local rheological properties (since the Brownian relaxation time is proportional to the viscosity) or chemical binding events (which result in an increase of the hydrodynamic radius). The latter can be used as a research tool for investigating binding kinetics in real time or as a custom-designed sensor for specific target molecules. By optimizing the magnetic nanoparticle with respect to the desired target molecule, this approach can be adapted to a wide variety of targets, such as specific molecules, proteins, and disease markers. At the same time, the ability to directly investigate reaction kinetics enables researchers to examine how different chemical/biological environments influence the binding process.Benefits
- Many biological and medical uses, including targeted drug delivery, magnetic separation, hyperthermal treatment and biosensors
- Rapid, sensitive detection
- Easy to use, even by relatively untrained personnel
- Infinite shelf life
- Medical: detecting disease-causing bacteria and viruses; detect and monitor DNA hybridization, DNA/RNA-protein, protein-protein, and protein-small molecule interactions
- Pharmaceuticals: drug discovery and evaluation
- Bioterrorism and environmental: remote sensing of airborne bacteria and detecting water toxins and contaminants
- In vitro: detection of local temperature and viscoelasticity within intercellular environments
- In vivo: immunoassays
|Title and Abstract||
Magneto-optic biosensor using bio-functionalized magnetized nanoparticles
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.
|Argonne National Laboratory||12/29/2009
|Technology ID||Development Stage||Availability||Published||Last Updated|