Imaging biology sample at high resolution with carbon nanotube AFM probe

The standard probe tips currently employed in AFM have some limitations in biological applications. Carbon nanotubes represent ideal AFM tip materials due to their small diameters, high aspect ratio and unique properties. In this paper carbon nanotubes were attached on the end of standard silicon tips to make carbon nanotube AFM tips. An extremely long lifetime at continuously high resolution of carbon nanotube tip was proved. The nanotube tips were used to image biological samples (DNA and IgG) with tapping mode atomic force microscopy in air. The microstructure of DNA and the characteristic Y-shaped structure of IgG were able to be observed that were previously unobservable with conventional AFM cantilever tips.