The development of nanotechnology for atomically precise manufacturing would benefit from the ability to attach specific chemical binding sites to scanning probe microscope tips. Carbon nanotubes offer several advantages as very sharp probes for nanotech tools. Writing at nanotechweb.org (requires free registration), Belle Dumé reports that Japanese scientists have succeeded in chemically attaching proteins specifically to the tips of multiwalled carbon nanotubes, avoiding contaminating attachments to the sides of the nanotubes. From “Proteins get attached to carbon nanotubes“:
A new way to attach proteins on to the tip of carbon nanotubes has been devised by researchers in Japan. Not only is the technique simpler than existing methods to attach biomaterials to nanotubes, it also eliminates the annoying problem of proteins attaching to the nanotube sidewalls. The protein-nanotube tips could be used to manipulate individual biomolecules and measure single biomolecule dynamics — something that is impossible with conventional silicon probes and laser tweezers.
The radius of carbon nanotube tips is about the same size as many nanobiomaterials. This means that nanotubes can be used to probe the structure of biomaterials such as proteins. What is more, CNTs have a very high mechanical strength and so can be used as force measurement probes attached to single protein molecules.
Although researchers have attached proteins to CNTs before now, the procedures they employed were complex. Moreover, there was the problem of “sidewall decoration”, where proteins become attached to the sides of the nanotubes through Van de Waals attractions. Now, Yoshikazu Nakayama of Osaka University and colleagues have overcome this challenge by developing a simple route to covalently attach proteins onto the sharpened tips of multiwalled carbon nanotubes (MWCNTs) without sidewall decoration.
The research was reported in the Journal of Applied Physics (abstract).