Featured Research

from universities, journals, and other organizations

Compact Biosensor For Wide-ranging Applications Under Development

Date:
February 18, 2009
Source:
Naval Research Laboratory
Summary:
Scientists are developing 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.

This portable magnetoresistive biosensor system utilizes an IC chip with an embedded giant magnetoresistance sensor array called the Bead ARray Counter (BARC). BARC detects paramagnetic microparticles that are used to label protein or DNA molecules of interest in a sandwich-based assay. The BARC chip is housed in an assay cartridge which contains an integrated fluid cell, microfludics bus and a PCMCIA connector to quickly interface with the compact Bead Array Sensor System (cBASS). cBASS includes a low power electromagnet, an automated fluidic system, and supporting electronics, all of which is controlled by a computer through a USB interface.
Credit: NRL photograph

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 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;
  • an onboard fully automated fluidic valve and pumping system;
  • a new electromagnet design with lower power requirements;
  • a faster data exchange via USB with the controlling computer; and
  • a rechargeable battery unit for enhanced portability (they have shrunk cBASS® down to approximately the size of a shoebox).

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.


Story Source:

The above story is based on materials provided by Naval Research Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

Naval Research Laboratory. "Compact Biosensor For Wide-ranging Applications Under Development." ScienceDaily. ScienceDaily, 18 February 2009. <www.sciencedaily.com/releases/2009/02/090203142523.htm>.
Naval Research Laboratory. (2009, February 18). Compact Biosensor For Wide-ranging Applications Under Development. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2009/02/090203142523.htm
Naval Research Laboratory. "Compact Biosensor For Wide-ranging Applications Under Development." ScienceDaily. www.sciencedaily.com/releases/2009/02/090203142523.htm (accessed September 30, 2014).

Share This



More Matter & Energy News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Argentina's Tax Evaders Detected, Hunted Down by Drones

Argentina's Tax Evaders Detected, Hunted Down by Drones

AFP (Sep. 30, 2014) — Argentina doesn't only have Lionel Messi the footballer, it has now also acquired "Mesi" the drone system which monitors undeclared mansions, swimming pools and soy fields to curb tax evasion in the country. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Do Video Games Trump Brain Training For Cognitive Boosts?

Do Video Games Trump Brain Training For Cognitive Boosts?

Newsy (Sep. 29, 2014) — More and more studies are showing positive benefits to playing video games, but the jury is still out on brain training programs. Video provided by Newsy
Powered by NewsLook.com
CERN Celebrates 60 Years of Science

CERN Celebrates 60 Years of Science

Reuters - Business Video Online (Sep. 29, 2014) — CERN, the European Organisation for Nuclear Research, celebrates 60 years of bringing nations together through science. As Joanna Partridge reports from inside the famous science centre it's also planning to turn the Large Hadron Collider particle accelerator back on after an upgrade. Video provided by Reuters
Powered by NewsLook.com
This 'Invisibility Cloak' Is Simpler Than Most

This 'Invisibility Cloak' Is Simpler Than Most

Newsy (Sep. 28, 2014) — Researchers from the University of Rochester have created a type of invisibility cloak with simple focal lenses. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins