a
NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa, Italy
E-mail: antonella.battisti@sns.it
;
Fax: +39 050509417
;
Tel: +39 050509767
b
Laboratory for Fluorescence Dynamics, University of California, Irvine, USA