A method of fabricating a nanotube probe tip and the resultant probe tip, particularly for use in an atomic force microscope. A moderately sharply peaked support structure has its tip cut or flattened to have a substantially flat end of size of about 20 to 200 nm across. The support structure may be formed by etching a conical end into a silica optical fiber. Nickel or other catalyzing metal such as iron is directionally sputtered onto the flat end and the sloped sidewalls of the support structure. The nickel is anisotropically etched to remove all the nickel from the sidewalls but leaving at least 15 nm on the flat end to form a small nickel dot. A nanotube is then grown with the nickel catalyzing its growth such that only a single nanotube forms on the nickel dot and its diameter conforms to the size of the nickel dot. In another preferred embodiment of the invention, a catalyst material can be directly deposited on to the probe end using charged particle beam deposition, such as electron beam deposition.