A team of researchers at Brown University (USA) has concluded that graphene, a material touted to replace silicon in future semiconductor devices, disrupts functions of living cells. If the results of the study are confirmed by others, graphene could end up in the same hazardous material category as carbon nanotubes.
Graphene has many unique properties, but from a toxicology perspective the most important is that it is often made as a dry powder with the potential for inhalation exposure. Graphene fragments that make up the powder have sharp, pointy edges that can penetrate cell walls and allow the rest of the fragment to be drawn into the cell.
The researchers started with toxicity studies of graphene, which showed that it did in fact disrupt cell functions. To discover why, atomically detailed computer simulations of the graphene material interacting with a living cell were created. The simulations indicated the same results as the toxicity experiments. After the simulations follow-up studies were performed on human lung, skin, and immune cells in Petri dishes, and they confirmed that graphene fragments as large as 10 microns can pierce and be swallowed up by living cells.
According to the researchers, this does not necessarily doom graphene to the category of potentially useful but hazardous materials, since it may be possible to engineer the structure of graphene materials to make them less toxic.