1. European Centre for the Validation of Alternative Methods, Institute for Health and Consumer Protection, Joint Research Centre, European Commission, Ispra (VA), Italy.
2. Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Wroclaw, Poland.
3. Nanotechnology and Molecular Imaging Unit, Institute for Health and Consumer Protection, Joint Research Centre, European Commission, Ispra (VA), Italy.