Navigation Links
Encoded metallic nanowires reveal bioweapons

When dangerous infectious diseases or biological weapons are suspected, fast help is required. The first step is a reliable, sensitive, and unambiguous, yet also fast and simple, identification of the pathogen; preferably, this test should be carried out on the spot, not in a laboratory. Portable miniature biodetection systems that can detect multiple pathogens simultaneously would be ideal for this task.

American researchers from Lawrence Livermore National Laboratory led by Jeffrey Tok, in collaboration with groups at Stanford University, University of California at Davis, and Oxonica Inc (formerly Nanoplex Technologies Inc). have now developed a new basis for such a multiplex device: they are using silver and gold "striped" nanowires as supports for simultaneous immunological tests for various pathogens. Individual patterns of stripes act in the role of "barcodes". These "nanobarcoded" particles are manufactured by Oxonica Inc using template-assisted electrochemical deposition of metals within the tiny cylindrical pores of alumina membranes. When deposited gold and silver are alternated in a defined way, nanowires with different characteristic stripe patterns are produced. The pattern of optical reflections from each sequence of stripes can later be unambiguously recognized--just like a barcode.

Antibodies aimed at specific pathogens can be attached to these wires. For their test runs, Tok and his colleagues selected harmless model substances to stand in for anthrax spores, smallpox virus, and protein toxins such as ricin and botulinum toxin. If a simultaneous test for all of these is desired, the anthrax antibody would be attached to stripe pattern 1, the smallpox antibodies to stripe pattern 2, and the toxin antibodies to stripe pattern 3, for example. If the corresponding model pathogen is present in a sample, it is "recognized" and bound by its antibodies. At this point, free antibodies that have been tagged with a fluorescent dye are added to the sample. These also dock onto the pathogen so that it is surrounded like the filling in a sandwich; giving the technique its name, "sandwich immunoassay". Measurement of the fluorescence now gives information about the pathogen concentration. Analysis of the reflection pattern allows the "barcode" of the fluorescing nanowires to be read. If only wires with stripe pattern 1 fluoresce, for example, then the sample contains anthrax spores. One particular advantage of nanowires over other antibody supports is that the tests do not take place at a surface but instead in a suspension, which makes them run much faster and more accurately. If nickel stripes are also added to the ends of the wires, they can then be magnetically separated out during the required washing steps--a prerequisite for a portable microbiodetector.


Source:John Wiley & Sons, Inc.

Related biology news :

1. Elusive HIV shape change revealed; Key clue to how virus infects cells
2. Timing is everything: First step in protein building revealed
3. Researchers reveal the infectious impact of salmon farms on wild salmon
4. A bacterial genome reveals new targets to combat infectious disease
5. Scientists reveal molecular secrets of the malaria parasite
6. Studies reveal methods viruses use to sidestep immune system
7. First real-time view of developing neurons reveals surprises, say Stanford researchers
8. Examination of internal wiring of yeast, worm, and fly reveals conserved circuits
9. Family trees of ancient bacteria reveal evolutionary moves
10. NYU study reveals how brains immune system fights viral encephalitis
11. Iron exporter revealed that may explain common human disorder
Post Your Comments:

(Date:11/19/2015)... -- Although some 350 companies are actively involved in molecular ... according to Kalorama Information. These include Roche Diagnostics, Hologic, Abbott ... of the 6.1 billion-dollar molecular testing market, according to ... Diagnostic s .    ... one company and only a handful of companies can ...
(Date:11/17/2015)... 17, 2015 Paris from ... --> Paris from 17 th until ... biometrics innovation leader, has invented the first combined scanner in ... same scanning surface. Until now two different scanners were required: ... can capture both on the same surface. This innovation ...
(Date:11/17/2015)... EASTON, Mass. , Nov. 17, 2015 ... a leader in the development and sale of broadly ... the worldwide life sciences industry, today announced it has ... of its $5 million Private Placement (the "Offering"), increasing ... to $4,025,000.  One or more additional closings are expected ...
Breaking Biology News(10 mins):
(Date:11/30/2015)... Florida , November 30, 2015 ... specializing in the development of innovative peptide and gene-based ... metastatic disease, today announced it will be presenting at ... on December 1, 2015 at 2.30 PM PT. Dr. ... and Strategic Advisor will be giving the presentation and ...
(Date:11/30/2015)... 2015  Aytu BioScience, Inc. (OTCQB: AYTU), a commercial-stage ... will present at two upcoming investor conferences. Aytu is ... virtual conference, to be held December 3, 2015, and ... held December 2 nd & 3 rd , ... streamed live via webcast. Josh Disbrow , ...
(Date:11/30/2015)... RATON, Florida and MAGDEBURG, Germany ... Congress of NeuroRehabilitation (ECNR) in Vienna, Austria ... 3rd European Congress of NeuroRehabilitation (ECNR) in ... 2015. --> NovaVision, a wholly owned subsidiary of ... the European version of its Internet-delivered NovaVision Therapy Suite at ...
(Date:11/30/2015)... ... November 30, 2015 , ... ... integration with MarkLogic, the Enterprise NoSQL database platform provider, creating a seamless ... , Smartlogic’s Content Intelligence capabilities provide a robust set of semantic tools ...
Breaking Biology Technology: