A recent study performed at Rice University explored the toxicity of different nanomaterials. A major difficulty in assessing nanomaterial toxicity is that there are many different varieties of nanomaterials and it is too costly to test all of them using traditional methods. The goal of the study was to develop a low-cost, high-throughput method to solve this problem.

The scientists achieved this goal by testing nanomaterials on a worm called Nematode C. Elegans. They designed assays that can test hundreds of nanomaterials in a week. These assays test the effects of each nanomaterial on thousands of worms. The material cost for each assay is only about 50 cents. As a demonstration, they applied their technology to test 20 nanomaterials and found that most of them showed some degree of toxicity. This method can serve effectively as a rapid initial screen to prioritize a few nanomaterials for more expensive, dedicated toxicology testing.

The tested graphene sample showed medium toxicity. Among all tested samples, graphene was more toxic than samples such as fullerene and TiO2 nano particles, but less toxic than some carbon nanotubes and nano silver. It was also found that graphene oxide is more toxic than graphene. It's important to emphasize that the toxicity is based on the tested samples, because even for the same class of nano particles with the same chemical compositions, the toxicity can vary a lot depending on factors such as the size, shape, and production process. Therefore, the toxicity for graphene can vary from batch to batch. As a result, one potential application of the method is to test which factors affect nano particle toxicity and use this knowledge for safe design of nano particles.