Magnetic biochip

Nov. 22, 2006
Giant Magnetoresistive (GMR) materials vary electrical resistance according to changes in an applied magnetic field.

The interaction generates electrical signals that can be read as data. Stanford researchers used this principle to build GMR sensor arrays for DNA analysis.

They first immobilized single-strand DNA receptors on the surface of a GMR sensor array. They then captured oligonucleotides with genetic sequences of interest. Oligonucleotides are structural units of DNA. Streptavidin is a protein that binds to biotin molecules, which oligonucleotides contain. The idea is to coat magnetic nanoparticles with streptavidin and let them bond to the biotin. Once that happens, the GMR sensor picks up changes in the magnetic field, which are converted into a unique electrical signature associated with each oligonucleotide under study.

The Stanford work is said to be the first to use a sensor array with this technique. The array contains more than 1,000 sensing elements within 1 mm2. It is integrated with 0.25- m BiCMOS circuitry on a chip. Such GMR sensor arrays may make feasible low-cost, portable diagnostic instruments, and ultimately compete with more complex and costly optical-based systems.

Sponsored Recommendations

Flexible Power and Energy Systems for the Evolving Factory

Aug. 29, 2024
Exploring industrial drives, power supplies, and energy solutions to reduce peak power usage and installation costs, & to promote overall system efficiency

Timber Recanting with SEW-EURODRIVE!

Aug. 29, 2024
SEW-EURODRIVE's VFDs and gearmotors enhance timber resawing by delivering precise, efficient cuts while reducing equipment stress. Upgrade your sawmill to improve safety, yield...

Advancing Automation with Linear Motors and Electric Cylinders

Aug. 28, 2024
With SEW‑EURODRIVE, you get first-class linear motors for applications that require direct translational movement.

Gear Up for the Toughest Jobs!

Aug. 28, 2024
Check out SEW-EURODRIVEs heavy-duty gear units, built to power through mining, cement, and steel challenges with ease!

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!