We present a quantum transport study of two- and
three-terminal carbon nanotube (CNT) based junctions.
We concentrate our analysis on functionalized and
recapped zig-zag CNTs exhibiting peculiar surface
electronic states localized at the zig-zag cut and at
the cap defect atoms respectively. We calculate the
linear conductance by means of the Green function
technique, within a pi-orbital description of the
carbon network, and show the interplay between these
peculiar localized states and the open transport
channels through the device. In correspondence of the
energies of the localized states, the conductance
behavior shows a Fano-like resonance. Possible
experimental conditions and setup in which such effect
could be detected are also discussed.