Researchers in China have discovered a way to change the solubility of carbon nanotubes, creating diverse biological applications. 

Weimin Liu at the Chinese Academy of Sciences, Beijing and colleagues have discovered a way to switch carbon nanotubes (CNTs) from being water to organo-soluble. The researchers attached ionic liquids to the carbon nanotubes and found that the switch can be achieved simply by anion exchange on the ionic liquid.

According to Liu, this switch in solubility would be useful in purifying CNTs as well as in further chemical functionalisation. 'This solubility switch can be achieved without further chemical reactions and is completely reversible,' said Liu. 

Liu said this work could create new opportunities for practical applications of CNTs in sensors and actuators in biological and biomedical science. Positively charged CNTs are particularly important in biomedical applications due to strong interactions with negatively charged cell membranes. The researchers are continuing their efforts by trying to use functional ionic liquids on CNTs without losing the reverse switchability.  

Sarah Dixon