Abstract
A novel method for tailoring organic nanoparticle colloids is described. Laser ablation of organic
microcrystalline powders in a poor solvent has opened new horizons for the synthesis of nanoparticles
because the powder sample is converted directly into a stable colloidal solution without additives and
chemicals. By tuning the laser wavelength, the pulse width, and the laser fl uence, we can control the
size and phase of the nanoparticles. We demonstrate examples of nanoparticle colloid preparation for
various organic compounds and describe their characteristics. We discuss the formation mechanism in
terms of the laser-induced fragmentation of organic solids and consider the potential application of
aqueous organic nanocolloids free from any additives and chemicals.
