We present a detailed study of synthesis, structural characterization of sharp, spike-like carbon structures and its application for high-resolution atomic-force microscopy (AFM) measurements of biological molecules. The probes are obtained by chemical vapor deposition of spike-like carbon structures on the apexes of common AFM silicon probes. The deposition process is carried out in carbonaceous gas mixture activated by a direct-current discharge. It was revealed by electron microscopy and Raman spectroscopy that the having dimensions at their ends of few nanometers the structures consist of amorphous carbon. The carbon spikes demonstrate high efficiency and resolutions in AFM studies of biological objects. Sub-molecular resolution is demonstrated on the samples of DNA and streptavidin molecules in AFM measurements with the ultra-sharp carbon tips.