Surface modified single molecules free-diffusion evidenced by fluorescence correlation spectroscopy.
We report on the free diffusion of single molecule near an interface studied using fluorescence correlation spectroscopy. In particular, we show that the chemical nature of the substrate may modify the free diffusion of a widely used molecule (rhodamine 6G), thus inducing unexpected effects in fluorescence correlation spectroscopy measurements. Our results show a strong influence, up to a few micrometer from the interface, of the surface polarity. This effect is assessed through the relative weight of the two dimensions diffusion process observed close to the surface. Our results are discussed in terms of competition between surface-solvent, solvent-molecule and molecule-surface specific interactions.
Boutin
Céline
C
Laboratoire de Nanotechnologie et d'Instrumentation Optique, LRC CEA, ICD CNRS FRE2848, Université de Technologie de Troyes, 12 rue Marie Curie, BP2060, 10010, Troyes cedex, France.
Jaffiol
Rodolphe
R
Plain
Jérôme
J
Royer
Pascal
P