NRL partners with industry to develop compact biosensor for wide-ranging ap...( Scientists at the Naval Research Lab...),Health

Scientists at the Naval Research Laboratory (NRL) are partnering with industry to develop a sensor system for biomolecules that could make a significant contribution to a variety of fields such as healthcare, veterinary diagnostics, food safety, environmental testing, and national security. NRL has developed a highly sensitive, portable biosensor system called the compact Bead Array Sensor System (cBASS). This innovative instrument utilizes a special integrated sensor chip, called the Bead ARray Counter (BARC), which contains an embedded array of giant magnetoresistive sensors. With 64, 200 m diameter sensors on the chip, BARC has the potential to detect 64 different target analytes. Through the efforts of Dr. Lloyd Whitman, former head of the Surface Nanoscience and Sensor Technology Section at NRL, the NRL-developed technology has been licensed to Seahawk Biosystems Corporation in Rockville, Maryland, for further development in veterinary diagnostic, clinical diagnostic, and environmental applications.

Researchers at NRL began working on the magnetoelectronic biosensor concept more than a decade ago, under the leadership of Dr. Richard Colton and former NRL researcher Dr. David Baselt. Dr. Baselt used a quantum-mechanical effect called giant magnetoresistance (GMR). In simplistic terms, GMR materials are magnetic field-dependent resistors, i.e. their resistance changes when subjected to an externally applied magnetic field. GMR devices are typically constructed of alternating magnetic and non-magnetic metal thin-film multilayers that are only nanometers in thickness. Dr. Baselt looked specifically at a type of GMR called multilayer GMR in which the resistance of two thin antiferromagnetically exchange-coupled layers, separated by a thin non-magnetic conducting layer, can be altered by changing the moments of the ferromagnetic layers from anti-parallel to parallel. This change decreases the spin-dependent interfacial scattering of charge carriers re
'/>"/>