Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sensor to have applications in homeland defense, safeguarding warfighters, clinical diagnostics

02.05.2007
Sensor will be capable of simultaneously detecting thousands of proteins, DNA, whole cells and pathogens

A Sandia National Laboratories research team is developing a new type of electrochemical sensor that uses a unique surface chemistry to reliably and accurately detects thousands of differing biomolecules on a single platform.

The new bioagent detection system could be applicable in homeland defense, safeguarding warfighters, and clinical diagnostics.

“A problem with the majority of existing biosensors is that they only look for one type of biomolecule [DNA or protein] at a time,” says Jason Harper, research team member. “This can often lead to inaccurate or inconclusive results and limits the use of the sensor. Where our sensor differs is that multiple characteristics of several bioagent targets can be tested on a single chip.”

For example, instead of using only an antibody that binds to the surface of an anthrax spore, the new Sandia sensor could test for several DNA sequences and internal and external proteins unique to anthrax. This provides numerous positive readings for the target agent or agents, significantly increasing confidence in the sensor results.

“Identification of several DNA sequences and protein markers will allow for detection of multiple targets and accurate discrimination between similar bioagent threats.” Harper says.

The new Sandia sensor will be able to simultaneously detect thousands of biomolecules on a single platform. By integrating antibodies, DNA, and other biomolecules on a single device, the number of lab instruments, volume of reagents required, time for analysis, and the cost of performing effectively thousands of tests are all reduced.

Sandia is a National Nuclear Security Administration (NNSA) laboratory.

The platform, a microfabricated chip, is just one inch by one inch in size. Several technological advances in microfabrication processes have increased the numbers of electrodes that can be produced on a sensor platform. A major challenge is how to pattern different biomolecules onto closely spaced micrometer-sized electrodes. The research team believes the answer lies in the electrodeposition of aryl diazonium salts.

The surface chemistry, produced by team members David Wheeler and Shawn Dirk, possesses several advantages over currently-used chemistry, Wheeler says.

“This diazonium-based surface chemistry can be selectively deposited onto several types of substrates by controlling the charge of the substrate in the diazonium solution,” Wheeler says. “Because the deposition of the diazonium molecules is based on the application of an electrical potential, the selective patterning of individually addressable electrodes is possible. Upon deposition, covalent bonds are formed with the substrate, producing a highly stable film.”

The chemistry is also compatible with a wide variety of biomolecules. DNA, antibodies, enzymes, and peptides all have been patterned onto arrays at Sandia using this chemistry.

After treating the sensor with the target solution, the array is washed and treated with a different solution containing molecules that bind to the other end of the target biomolecule, forming a “sandwich.” These secondary labels form an electroactive product that is detected by the electrode.

Says team member Ronen Polsky, “We are also investigating a new electrochemical detection method, using electrocatalytic nanoparticles, that we hope will eliminate the extra washing and labeling steps. This will greatly simplify the end device.”

Some of this work was recently featured in an article in Langmuir, published by the American Chemical Society. Diazonium chemistry was used to selectively deposit the enzyme horseradish peroxidase, which was then used to electrochemically detect hydrogen peroxide.

Electrochemical detection holds many advantages over other common optical-based biosenors. By eliminating optics and using semiconductor microarrays the end device is smaller, more rugged, and simpler in design.

Eventually the sensor array will be integrated in a deployable electrochemical sensor that will have an electronic readout identifying the biomolecules detected, or wirelessly transmit the results to a computer or network. Reaching that point will take anywhere from two to five years, says Ronen.

Currently the sensor arrays in the project allow for selective identification of nine biomolecules, Harper says. However, the work has kindled the interest of commercial sensor companies. The Sandia team recently traveled to Seattle to test their surface chemistry on a commercial array produced by CombiMatrix, a company that specializes in producing semiconductor arrays with more than 12,000 individually addressable electrodes in an area less than one inch square.

“The team successfully patterned peptide ligands onto 2,151 individual electrodes out of an array of 12,544 electrodes,” says Susan Brozik, project principal investigator. “The resulting electrochemical signal from protein biodetection on the patterned electrodes formed the Sandia Thunderbird symbol as well as the CombiMatrix logo.”

Because of this initial success, Sandia and CombiMatrix are pursuing a cooperative research and development agreement (CRADA) for further development of a sensor using Sandia’s surface chemistry and CombiMatrix’s electrode array, to ultimately test for thousands of biomolecules simultaneously. Funding for this research has been provided by Sandia’s internal Laboratory Directed Research and Development (LDRD) program, the National Consortium for Measurement and Signatures Intelligence (MASINT) Research, a Defense Intelligence Agency program that seeks to promote collaborated research among academia, industry, laboratories, and DOE. CombiMatrix is funded by the Defense Threat Reduction Agency.

Chris Burroughs | EurekAlert!
Further information:
http://www.sandia.gov

Further reports about: CombiMatrix DNA DNA sequence Electrochemical Sandia thousands

More articles from Life Sciences:

nachricht Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>