The authors developed a room temperature atomic layer deposition (ALD) system that can deposit TiO2 on gold nanoparticles by using tetrakis(dimethylamino) titanium and plasma-excited humidified argon. The growth per cycle of TiO2 was measured to be 0.25 nm/cycle on a monitored Si sample. For applying the nanoparticle coating, the source material, i. e., gold particles, is electrostatically attached to the susceptor in the ALD system to avoid their gas transport. These particles are then mixed by a rotating scraper during the ALD process. This system allows a conformal deposition of TiO2 without the aggregation of nanoparticles. The thickness of TiO2 for shell coating is controlled by counting the number of ALD cycles. The deposition of TiO2 coating with a nanometer scale thickness on the gold nanoparticle is demonstrated in this paper. (C) 2016 American Vacuum Society.