Positively charged gold nanoparticles can be produced in the aerosol state by ultraviolet irradiation of aerosols at wavelengths above the gold ionization energy. Spark-discharge-generated aerosol gold nanoparticles were mobility-classified, neutralized, and then exposed to ultraviolet irradiation at 185 nm. The charge states were determined using a tandem differential mobility analyzer system, and the results revealed that there was no significant dependence of charging probability upon mobility diameter between 4 and 60 nm (1.55 +/- 0.26 in positive elementary charge), probably because of the agglomerated nature of the particles. The ionized particles could be deposited to form nanoscale island patterns on a substrate without the use of templates.