Prof. Dr. Thorsten Stumpf

Director Institute of Resource Ecology
Phone: +49 351 260 3210

Qnano-Projects:  Radiolabelling of TiO2 and Ag nanoparticles and multi-wall carbon nanotubes using cyclotron techniques

The investigation of the environmental fate of nanoparticles (NPs) is in dire need of sensitive detection methods that allow for the easy tracing of nano materials in complex media such as ground or surface waters and the geosphere. Radioactive labelling of NPs provides the possibility of tracing NPs with high sensitivity and selectivity not achieved by conventional techniques.

Our Qnano-funded projects, in cooperation with the IHCP Nanobioscience unit at the Joint Research Center, investigate different cyclotron-based methods for the possible radiolabelling of TiO2 and Ag NPs and multi-wall carbon nanotubes (MWCNTs).

Direct activation of nanoparticles:

Nanoparticles can be directly activated by proton bombardement. Proton irradiation of a sufficient high energy to trigger nuclear reactions is used to produce radiotracers directly inside the original nanopowder.

This method has been successfully employed to radiolabel TiO2-NPs and MWCNTs.

Recoil activation of nanoparticles:

If no suitable nuclear reactions for direct activation of NPs are accessible, recoil labelling can be used as an alternative approach. In this case a mixture of the nanopowder with a lithium compound is irradiated. The Li-7 undergoes a nuclear (p,n) reaction to Be-7, which is then incorporated into the NP structure due to the recoil energy.

The strategy was successfully tested on TiO2-NP and MWCNTs and should be generally adoptable for a wide range of nanoparticles.

Recoil Labelling of MWCNTs

Synthesis of radiolabelled nanoparticles

If the above-mentioned strategies are not possible, radioactive precursors can be produced using a cyclotron and be used as starting material in a NP-synthesis. This approach is useful for Ag-NPs as the high energy intake during irradiation would cause the melting of Ag-NPs.


  • Talk, Qnano Conference, Prague, 2013
  • Talk, Cycleur Meeting, Ispra, 2012
  • Talk, Nanosafe 2012, Grenoble, 2012   
  • Poster, internal evaluation, Dresden, 2012


    Dr. Heike Hildebrand

    Dr. Karsten Franke

    Dr. Stefan Schymura

    Dr. Neil Gibson (JRC)


sponsored by:

QualityNano Logo