We have developed a method to coat single-walled carbon nanotubes attached to AFM tips with conformal fluorocarbon polymer films formed in an inductively coupled plasma reactor. The polymer provides a chemically inert and electrically insulating outer layer and mechanically stabilizes the attached nanotube sufficiently to enable imaging in liquids without the need for an intervening adhesive. Electrical pulse etching of the insulating coating exclusively at the nanotube tip end results in well-defined highly conductive nanoelectrodes. For these probes, the conductive properties of the nanotubes are not affected by the coating. Some nanoelectrodes behave as rectifying diodes, which may be developed into novel molecular devices integrated onto scanning probes.