It depends on the material that you would have in 1 dimensional shape. For example, you can obtain silicon nanoparticles (1D) by sputtering deposition technique using a proper sublayer template. By using a top-down approach (for example ball milling technique or electrochemical approach that produces porous silicon) you obtain a mixture of nanostructures with different dimensionality (0-D, 1D, 2D...).