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:11/20/2015)... Connecticut , November 20, 2015 ... authentication company focused on the growing mobile commerce market ... CEO, Gino Pereira , was recently interviewed on ... interview will air on this weekend on Bloomberg ... Latin America . --> NXTD ) ("NXT-ID" ...
(Date:11/19/2015)... MOUNTAIN VIEW, Calif. , Nov. 19, 2015 /PRNewswire/ ... authentication market, Frost & Sullivan recognizes BIO-key with the ... Strategy Leadership. Each year, Frost & Sullivan presents this ... comprehensive product line catering to the needs of the ... which the product line meets and expands on customer ...
(Date:11/19/2015)... 2015  Although some 350 companies are actively involved ... few companies, according to Kalorama Information. These include Roche Diagnostics, ... market share of the 6.1 billion-dollar molecular testing market, ... for Molecular Diagnostic s .    ... controlled by one company and only a handful of ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... Malaysia , Nov. 24, 2015  Asia-Pacific ... contract research organisation (CRO) market. The trend of ... in lower margins but higher volume share for ... capacity and scale, however, margins in the CRO ... Organisation (CRO) Market ( ), finds ...
(Date:11/24/2015)... N.J. (PRWEB) , ... November 24, 2015 , ... The ... the recipient of the 2016 USGA Green Section Award. Presented annually since 1961, the ... through his or her work with turfgrass. , Clarke, of Iselin, N.J., ...
(Date:11/24/2015)... SUNNYVALE, Calif. , Nov. 24, 2015 ... executives will be speaking at the following conference, and ... New York, NY      Tuesday, December 1, ... New York, NY      Tuesday, December 1, ...      Piper Jaffray Healthcare Conference, New York, NY ...
(Date:11/24/2015)... Therapeutics, Inc. (NASDAQ: HALO ) will be presenting at the ... on Wednesday, December 2 at 9:30 a.m. ET/6:30 a.m. PT . ... a corporate overview. th Annual Oppenheimer Healthcare Conference ... a.m. PT . Jim Mazzola , vice president of ... --> th Annual Oppenheimer Healthcare Conference in ...
Breaking Biology Technology: