1. NEST, Istituto Nanoscienze-CNR, Scuola Normale Superiore, Piazza S. Silvestro 12, 56127 Pisa, Italy
2. Istituto Officina dei Materiali CNR, Laboratorio TASC, Area Science Park – S S 14, km 163.5, I-34012 Trieste, Italy
3. Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy
4. Center for Nanotechnology Innovation@NEST, Istituto Italiano di Tecnologia, Piazza S. Silvestro 12, 56127 Pisa, Italy