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 µm 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 resulting in a decrease in the resistance of the GMR material. Dr. Baselt realized this very sensitive phenomenon could have potential in the development of sensors for biological materials which are naturally biochemically specific, but are not usually magnetic. By attaching tiny paramagnetic particles to biomolecules, such as proteins or single-stranded DNA, scientists could then perform standard sandwich-type immuno or nucleic acid hybridization assays over the GMR sensors. The GMR sensors, each covered with complementary protein or single-stranded DNA (the "probe"), could then detect the magnetically labeled biomolecules (the "target") the assays were designed to identify.
A decade in the making, the instrumentation that reads the BARC® chip is called the "compact Bead Array Sensor System" (cBASS®). NRL's current engineering team is led by Dr. Cy Tamanaha, working with Dr. Jack Rife, Mr. Matthew Kniller, and Mr. Michael Malito. The engineering team has worked to make many improvements to cBASS®, including:- a new quick assembly assay cartridge with an integrated microfluidic cell, PCMCIA interface and kinematic microfluidics bus;
Ultimately, the success of the NRL's magnetoelectronic biosensor depends on the performance of the microbead label assays whose continued development is currently spearheaded by Dr. Shawn Mulvaney with the assistance of Ms. Kristina Myers. Over the past several years, NRL has made significant strides in surface biofunctionalization and assay development. With these advances, they have achieved high sensitivity and speed; low, non-specific binding with femtomolar DNA and attomolar protein detection, typically in less than 10 minutes. One important characteristic of the NRL-developed assays is that the size of the microbead labels allows for either magnetoelectronic detection with GMR sensors, or optical enumeration with image processing software via a standard low-power microscope. The detection sensitivity under each method is nearly identical. However, there are differences in the two methods related to the size of the detection system and the cost of the consumables used.
Donna McKinney | EurekAlert!
Further reports about: > BARC® > Biosensor > DNA > GMR > NRL > Sensor > USB > biomolecules > cBASS® > controlling computer > faster data exchange > fully automated fluidic valve > integrated microfluidic cell > kinematic microfluidics bus > magnetic field > pumping system > rechargeable battery > sensor system
Improved stability of plastic light-emitting diodes
19.04.2018 | Max-Planck-Institut für Polymerforschung
Intelligent components for the power grid of the future
18.04.2018 | Christian-Albrechts-Universität zu Kiel
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.
Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
19.04.2018 | Materials Sciences
19.04.2018 | Physics and Astronomy
19.04.2018 | Physics and Astronomy