Perylene nanoparticles can be formed.  (RDC 8/18/2011)

“Peryleneor perilene is a polycyclic aromatic hydrocarbon with the chemical formula C20H12, occurring as a brown solid. It or its derivatives may be carcinogenic, and it is considered to be a hazardous pollutant. In cell membrane cytochemistry, perylene is used as a fluorescent lipid probe. It is the parent compound of a class of rylene dyes.” (Wikipedia, Perylene, 8/15/2011)

Materials
Nanoparticles

Recent Journal Articles

Evolution of Light Absorption and Emission Characteristics of Organic Perylene Nanoparticles through Hydrothermal Process: Application to Solar Cells
(3056–3063)
Advanced Functional Materials 21  #16 (2011)
Cho et al of Korea University and the University of Incheon, South Korea, controlled the π–π interactions of polymorphic organic perylene nanoparticles (NPs) using a hydrothermal process. The light-emission colors of the perylene NPs vary gradually from yellow to green to light blue with increasing hydrothermal temperature from 110 to 160 °C.  An enhanced crystallinity of the NPs from 110 °C to a critical temperature Tc of 140 °C and a transition to the amorphous phase above Tc are observed.  (RDC 8/15/2011)