Topology related changes in the local density of states near the apex of ca
rbon nanocones are investigated using both tight-binding and ab initio calc
ulations. Sharp resonant states are found to dominate the electronic struct
ure in the region close to the Fermi energy. The strength and the position
of these states with respect to the Fermi level depend sensitively on the n
umber and the relative positions of the pentagons constituting the conical
tip. Carbon nanocones are thus proposed as good candidates for nanoprobes i
n scanning probe microscopy.