Biological degradation of carbon-based nanomaterials


Carbon-based nanomaterials are characterised by pronounced stability and are increasingly used in industry because of these properties. With their project, Hans-Peter Kohler and his team provide important insights to better estimate what happens to carbon-based nanomaterials in the environment.

Background (completed research project)

Carbon-based nanomaterials (CBN), such as carbon nanotubes and fullerenes, have excellent thermal and electrical conductivities and are extremely resistant to heat and cold as well as chemical and mechanical stresses. These properties are of great benefit to industry. The production of carbon-based nanomaterials is growing steadily. It currently stands at around 300 tonnes per year worldwide for carbon nanotubes and fullerenes. At the same time, these properties also imply that carbon-based nanomaterials released in the environment also resist physical, chemical and biological factors and are therefore very difficult to break down. At the start of NRP 64, little was known about the degradation and conversion processes of these materials. Together with his team, Hans-Peter Kohler developed methods to investigate the degradation of different carbon-based nanomaterials, both quantitatively and qualitatively.


The researchers systematically studied the reduction of 13 different CBN by the enzyme peroxidase. The experiments showed that this degradation is very slow and suggest that CBN, once they reach the environment, can potentially remain unchanged for decades. The research project also described characteristics of CBN that make the materials more or less resistant to conversion and degradation processes. Finally, as part of this project, a publication was produced that summarizes the existing techniques and results for the qualitative and quantitative analysis of CBN and their applications.


The project provides basic knowledge that should be considered for the evaluation of risks of carbon-based nanomaterials. The results underline the importance of systematically characterising carbon-based nanomaterials in order to estimate what happens to these materials in the environment.

Original title

Biotransformation of fullerenes and carbon nanotubes (BioCarb)

Project leader(s)

  • Dr. Hans-Peter Kohler


  • Prof. Juliane Hollender



Further information on this content


Dr. Hans-Peter Kohler Umweltmikrobiologie Eawag Uberlandstrasse 133 8600 Dübendorf +41 44 823 51 52