Nanodisks used to encrypt information
PhysOrg.com reports that U.S. researchers have used nanotechnology tricks to develop nanodisks which could be useful to create codes to encrypt information. This method, which conceptually is similar to barcodes, could be used for DNA tagging or tracking goods and people. Even if this looks interesting, the best part is that the article mentions twice that the researchers belong to Northeastern University located in Boston, Massachusetts. But while I was searching for references for this post, I quickly found that the researchers belonged to Northwestern University located in Evanston, Illinois. Digg users and other bloggers contributed to propagate the error. Why do they forget to check the facts before relaying information? But read more...
As I'm writing this post, Google returns 50 results for a query about "Nanodisk Codes" (with the quotes). The top result is the PhysOrg.com article, and about half of the remaining ones are quoting it, wrongly attributing the findings to researchers at Northeastern University. And already 21 people voted on Digg to promote the article -- and the mistake.
In fact, this research was led by Chad Mirkin, the Director of the International Institute for Nanotechnology, the George Rathmann Professor of Chemistry at the Northwestern University Department of Chemistry, Professor of Medicine, and Professor of Materials Science and Engineering. With all these qualifications, it's hard to miss that Mirkin and his research group work for Northwestern University and not for Northeastern University.
Besides this PhysOrg.com's mistake, the rest of the article seems accurate. And you can see above some binary codes formed by nanodisks carved out of nanorods. (Credit: Chad Mirkin research group)
And how does this work? "Each of the five disk-pair locations along the rod can correspond to a '0' or a '1,' depending on whether that location is occupied by a disk pair. For example, if only one disk pair is present, and it is situated at the third location, that code is read as 00100. If two disk pairs are present, at the fourth and fifth locations, the code is 00011.
The author adds that this method could be used for "biological tagging, a method of tracking and detecting individual biological materials, such as DNA. The researchers proved this by attaching pieces of single-stranded DNA to the surfaces of the nanodisks in a 11011 code. Each of these strands was complementary to half of a 'target' DNA strand—the strand being tagged. The other half of the target strand was complementary to a 'reporter' strand, rendered spectroscopically active with dye. The overall structure formed a three-strand 'sandwich,' with the target strand in the middle."
For more information, this research work has been published in Nano Letters under the title "Nanodisk Codes" (Volume 7, Number 12, Pages 3849-3853, December 2007). Here is a link to the abstract. "We report a new encoding system based upon dispersible arrays of nanodisks prepared by on-wire lithography and functionalized with Raman active chromophores. These nanodisk arrays are encoded both physically (in a "barcode" pattern) and spectroscopically (Raman) along the array. These structures can be used in covert encoding strategies because of their small size or as biological labels with readout by scanning confocal Raman spectroscopy. As proof-of-concept, we demonstrate their utility in DNA detection in a multiplexed format at target concentrations as low as 100 fM."
Sources: Laura Mgrdichian, PhysOrg.com, December 27, 2007; and various websites
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