US Patent 7225082 - Nanowire barcodes

http://www.freepatentsonline.com/7225082.html

While one of the common applications of quantum dots is in biomarker applications other nanoparticles may also be applied to this area. This patent from Oxonica discloses the use of segmented superparamagnetic nanowires that function as a barcode identification. Claim 20 reads:

20. A freestanding particle comprising 2 to 50 segments, wherein the particle length is from 20 nm to 50 microns, and the particle width is from 5 nm to 50 microns, and wherein at least one of said segments is comprised of a superparamagnetic compound.