A new DNA-based method, published in the journal Nature by Xiaomin Tu and Ming Zheng of DuPont and co-authors Suresh Manohar and Professor Anand Jagota, can sort and separate specific types of carbon nanotubes from a mixture.
From Nature News and Views: "Pure nanotubes are highly sought after for their use in electronics and other applications. Using carbon nanotubes in electronics applications requires precise knowledge of their structure and electronic properties. But current methods for producing carbon nanotubes generate mixtures of tubes with different diameters and symmetry, or ‘chirality’. Until now it has been very challenging to disentangle these mixtures and purify single species. In this week’s Nature, Ming Zheng and colleagues show that tailored DNA sequences — repeats of one purine plus one or more subsequent pyrimidines — can purify every single species in a nanotube mixture. The authors propose that these DNA sequences form particularly stable three-dimensional barrel structures when wrapped around a nanotube, which could be responsible for the selectivity." Click here for the college article.