Researchers from Lawrence Livermore National Laboratory review several of the latest technologies in the most recent issue (Issue 3, 2007), of the British journal “The Analyst,” which appears online at http://www.rsc.org/Publishing/Journals/AN/Article.asp?Type=CurrentIssue.
“It’s important to provide a summary of the latest technologies and approaches for sensing systems and platforms that could lead to bioagent detectors for responders to use in the field,” said LLNL’s lead author Jeffrey Tok. Other authors include Nicholas Fischer and Theodore Tarasow of LLNL’s BioSecurity and Nanosciences Laboratory.
One technique, previously described by Tok and colleagues, involves using a barcode system, similar to the barcodes used on retail products, to detect biological agents in the field. Nanowires built from sub-micrometer layers of different metals, including gold, silver and nickel, are able to act as “barcodes” for detecting a variety of pathogens, such as anthrax, smallpox, ricin and botulinum toxin. The approach could simultaneously identify multiple pathogens via their unique fluorescent characteristics.
Another detection strategy involves the development of electrical current-based readout of the nanowires for protein and virus sensing. The wires are arranged as field-effect transistors (FETs), where slight variations at the surface produce a change in conductivity. Developers of this technology predict that a high-density nanowire-circuit array geared toward pathogen detection could be built on a large scale suitable for biosecurity surveillance.
Physical, chemical and optical properties that can be tuned to detect a particular bioagent are key to microbead-based immunoassay sensing systems. A unique spectral signature or fingerprint can be tied to each type of bead. Beads have been joined with antibodies to specific biowarfare agents. This method has been demonstrated in the Autonomous Pathogen Detection System (APDS), a technology developed by Lawrence Livermore researchers. APDS contains an aerosol collector to constantly “inhale” particles from its surrounding environment for analysis.
Microarray-based immunoassay sensing approaches can be used to detect bacteria, such as the E. coli recently found in spinach and other fresh-packed greens. This approach can differentiate pathogens from harmless bacteria. In an analogous technique called aptamer microarray, short single strand chains of DNA (less than 100 nucleotides) are developed that bind to target molecules and fold into complex structures. The folding event results in an easy-to-read electrical charge. This binding-induced signaling strategy is particularly well suited for sensing in complex samples.
In a whole-cell-based immunoassay sensing system, an engineered B lymphocyte cell in which both pathogen-sensing membrane-bound antibodies and an associated light-emitting reporting system are all expressed in vivo. The B lymphocyte cell-based sensing system, termed CANARY, centers on an easily expressed calcium-sensitive bioluminescent protein from the Aequoria victoria jellyfish. When exposed to targeted biowarfare compounds, an increase in photons was observed within the B lymphocyte cells in a matter of seconds. The photon changes can then be easily detected using an inexpensive optical system.
“The ability to miniaturize and adapt traditional bench-top immunoassay protocols to a fully automated micro-or nano-fluidic chip holds tremendous promise to enable multiplex, efficient, cost-effective and accurate pathogen sensing systems for both biodefense and medical applications,” Tok said.
Anne Stark | EurekAlert!
Cells communicate in a dynamic code
19.02.2018 | California Institute of Technology
Studying mitosis' structure to understand the inside of cancer cells
19.02.2018 | Biophysical Society
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
19.02.2018 | Materials Sciences
19.02.2018 | Materials Sciences
19.02.2018 | Life Sciences