1.D.119.  The Conical Gold Nanotube (CGNT) Family 

Siwy et al. 2004 have described a synthetic membrane that contains a single conical gold nanotube. The advantage of this membrane pore mimic is that the surface charge and chemistry of the nanotube wall can be varied by judicious choice of electrolyte or by thiol chemisorption. This has allowed construction of  conical Au nanotubes that rectify the ion current and allow definition of  the mechanism of this function.